Subjects -> EARTH SCIENCES (Total: 771 journals)
    - EARTH SCIENCES (527 journals)
    - GEOLOGY (94 journals)
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    - HYDROLOGY (29 journals)
    - OCEANOGRAPHY (88 journals)

EARTH SCIENCES (527 journals)            First | 1 2 3     

Showing 401 - 371 of 371 Journals sorted alphabetically
Physical Geography     Hybrid Journal   (Followers: 8)
Physical Science International Journal     Open Access  
Physics in Medicine & Biology     Full-text available via subscription   (Followers: 15)
Physics of Life Reviews     Hybrid Journal   (Followers: 1)
Physics of Metals and Metallography     Hybrid Journal   (Followers: 18)
Physics of Plasmas     Hybrid Journal   (Followers: 10)
Physics of the Earth and Planetary Interiors     Hybrid Journal   (Followers: 34)
Physics of the Solid State     Hybrid Journal   (Followers: 6)
Physics of Wave Phenomena     Hybrid Journal  
Physics World     Full-text available via subscription   (Followers: 18)
Physik in unserer Zeit     Hybrid Journal   (Followers: 9)
Pirineos     Open Access  
Planet     Open Access   (Followers: 4)
Plasma Physics and Controlled Fusion     Hybrid Journal   (Followers: 6)
Plasma Physics Reports     Hybrid Journal   (Followers: 7)
Polar Record     Hybrid Journal   (Followers: 2)
Positioning     Open Access   (Followers: 4)
Pramana     Open Access   (Followers: 13)
Precambrian Research     Hybrid Journal   (Followers: 7)
Preview     Hybrid Journal  
Proceedings of the Geologists' Association     Full-text available via subscription   (Followers: 6)
Proceedings of the Linnean Society of New South Wales     Full-text available via subscription   (Followers: 2)
Proceedings of the Yorkshire Geological Society     Hybrid Journal   (Followers: 1)
Progress in Earth and Planetary Science     Open Access   (Followers: 16)
Pure and Applied Geophysics     Hybrid Journal   (Followers: 12)
Quarterly Journal of Engineering Geology and Hydrogeology     Hybrid Journal   (Followers: 4)
Quaternary     Open Access  
Quaternary Australasia     Full-text available via subscription  
Quaternary Geochronology     Hybrid Journal   (Followers: 8)
Quaternary International     Hybrid Journal   (Followers: 14)
Quaternary Research     Full-text available via subscription   (Followers: 19)
Quaternary Science Advances     Open Access  
Quaternary Science Reviews     Hybrid Journal   (Followers: 26)
Radiocarbon     Hybrid Journal   (Followers: 12)
Remote Sensing     Open Access   (Followers: 57)
Remote Sensing Applications : Society and Environment     Full-text available via subscription   (Followers: 9)
Remote Sensing in Earth Systems Sciences     Hybrid Journal   (Followers: 5)
Remote Sensing Letters     Hybrid Journal   (Followers: 45)
Remote Sensing Science     Open Access   (Followers: 29)
Rendiconti Lincei     Hybrid Journal  
Reports on Geodesy and Geoinformatics     Open Access   (Followers: 8)
Reports on Mathematical Physics     Full-text available via subscription   (Followers: 2)
Research & Reviews : Journal of Space Science & Technology     Full-text available via subscription   (Followers: 18)
Resource Geology     Hybrid Journal   (Followers: 6)
Resources, Environment and Sustainability     Open Access   (Followers: 1)
Results in Geochemistry     Open Access  
Results in Geophysical Sciences     Open Access  
Reviews in Mineralogy and Geochemistry     Hybrid Journal   (Followers: 4)
Reviews of Modern Physics     Full-text available via subscription   (Followers: 31)
Revista Cerrados     Open Access  
Revista de Ciências Exatas Aplicadas e Tecnológicas da Universidade de Passo Fundo : CIATEC-UPF     Open Access  
Revista de Ingenieria Sismica     Open Access  
Revista de Investigaciones en Energía, Medio Ambiente y Tecnología     Open Access  
Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales     Open Access  
Revista de Teledetección     Open Access  
Revista Geológica de Chile     Open Access  
Revue Française de Géotechnique     Hybrid Journal  
Rock Mechanics and Rock Engineering     Hybrid Journal   (Followers: 7)
Rocks & Minerals     Hybrid Journal   (Followers: 3)
Russian Geology and Geophysics     Hybrid Journal   (Followers: 2)
Russian Journal of Mathematical Physics     Full-text available via subscription  
Russian Journal of Pacific Geology     Hybrid Journal  
Russian Physics Journal     Hybrid Journal   (Followers: 1)
Science China Earth Sciences     Hybrid Journal   (Followers: 3)
Science News     Hybrid Journal   (Followers: 11)
Science of Remote Sensing     Open Access   (Followers: 7)
Scientific Annals of Stefan cel Mare University of Suceava. Geography Series     Open Access  
Scientific Journal of Earth Science     Open Access   (Followers: 1)
Scientific Reports     Open Access   (Followers: 85)
Sedimentary Geology     Hybrid Journal   (Followers: 20)
Sedimentology     Hybrid Journal   (Followers: 15)
Seismic Instruments     Hybrid Journal   (Followers: 1)
Seismological Research Letters     Full-text available via subscription   (Followers: 12)
Soil Dynamics and Earthquake Engineering     Hybrid Journal   (Followers: 14)
Soil Security     Open Access   (Followers: 3)
Solid Earth     Open Access   (Followers: 5)
Solid Earth Discussions     Open Access   (Followers: 1)
Solid Earth Sciences     Open Access   (Followers: 1)
South African Journal of Geomatics     Open Access   (Followers: 2)
Standort - Zeitschrift für angewandte Geographie     Hybrid Journal   (Followers: 2)
Stratigraphy and Geological Correlation     Full-text available via subscription   (Followers: 2)
Studia Geophysica et Geodaetica     Hybrid Journal   (Followers: 1)
Studia Geotechnica et Mechanica     Open Access  
Studia Universitatis Babes-Bolyai, Geologia     Open Access  
Survey Review     Hybrid Journal   (Followers: 6)
Surveys in Geophysics     Hybrid Journal   (Followers: 3)
Swiss Journal of Palaeontology     Hybrid Journal   (Followers: 4)
Tectonics     Full-text available via subscription   (Followers: 15)
Tectonophysics     Hybrid Journal   (Followers: 24)
Tellus A     Open Access   (Followers: 21)
Tellus B     Open Access   (Followers: 20)
Terra Latinoamericana     Open Access  
Terra Nova     Hybrid Journal   (Followers: 5)
The Compass : Earth Science Journal of Sigma Gamma Epsilon     Open Access  
The Holocene     Hybrid Journal   (Followers: 16)
The Leading Edge     Hybrid Journal   (Followers: 1)
Transportation Infrastructure Geotechnology     Hybrid Journal   (Followers: 8)
Turkish Journal of Earth Sciences     Open Access  
UD y la Geomática     Open Access  
Unconventional Resources     Open Access  
Underwater Technology: The International Journal of the Society for Underwater     Full-text available via subscription   (Followers: 1)
Universal Journal of Geoscience     Open Access  
Unoesc & Ciência - ACET     Open Access  
Vadose Zone Journal     Open Access   (Followers: 5)
Volcanica     Open Access  
Water     Open Access   (Followers: 10)
Water International     Hybrid Journal   (Followers: 19)
Water Resources     Hybrid Journal   (Followers: 21)
Water Resources Research     Full-text available via subscription   (Followers: 94)
Watershed Ecology and the Environment     Open Access  
Weather, Climate, and Society     Hybrid Journal   (Followers: 15)
Wiley Interdisciplinary Reviews - Climate Change     Hybrid Journal   (Followers: 33)
World Environment     Open Access   (Followers: 1)
Yearbook of the Association of Pacific Coast Geographers     Full-text available via subscription   (Followers: 2)
Yugra State University Bulletin     Open Access   (Followers: 1)
Zeitschrift der Deutschen Gesellschaft für Geowissenschaften     Full-text available via subscription   (Followers: 3)
Zeitschrift für Geomorphologie     Full-text available via subscription   (Followers: 5)
Zitteliana     Open Access  
Землеустрій, кадастр і моніторинг земель     Open Access   (Followers: 1)

  First | 1 2 3     

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Journal Prestige (SJR): 0.634
Citation Impact (citeScore): 2
Number of Followers: 10  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2073-4441
Published by MDPI Homepage  [84 journals]
  • Water, Vol. 14, Pages 2949: Pretreatment Hydrolysis
           Acidification/Two-Stage AO Combination Process to Treat High-Concentration
           Resin Production Wastewater

    • Authors: Shengping Cao, Weiwei Jiang, Minyan Zhao, Ankang Liu, Mingxiu Wang, Qu Wu, Yongjun Sun
      First page: 2949
      Abstract: The rapid development of the resin industry has led to a large amount of high-concentration resin production wastewater, which has created serious water pollution problems while limiting the development of related enterprises. In this study, a combined pretreatment hydrolysis acidification/two-stage anaerobic oxic (AO) process for high-concentration resin production wastewater was constructed, and the effect of operation time on the treatment efficiency of the hydrolysis acidification and the two-stage AO unit was investigated using chemical oxygen demand (COD), total nitrogen (TN), and NH3-H (ammonia nitrogen) as indicators. The effect of operation time on the treatment efficiency of the hydrolysis acidification and the two-stage AO unit was investigated. Results showed that the pretreatment of “alkaline digestion + ozone oxidation” could effectively remove volatile phenols and phenolic organic pollutants from the wastewater. The average removal rates of COD, TN, and NH3-H (ammonia nitrogen) of resin production were 91.96%, 85.35%, and 85.67%, respectively. The average concentrations of final biochemical effluent were 404.7, 21.4, and 11.4 mg/L, respectively.
      Citation: Water
      PubDate: 2022-09-20
      DOI: 10.3390/w14192949
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2950: Potential Toxic Impacts of Hg Migration in the
           Disjointed Hyporheic Zone in the Gold Mining Area Experiencing River Water
           Level Changes

    • Authors: Ruiping Liu, Fei Liu, Jiangang Jiao, Youning Xu, Ying Dong, El-Wardany R.M., Xinshe Zhang, Huaqing Chen
      First page: 2950
      Abstract: In order to study the occurrence form, vertical migration and transformation and the potential ecological risk of Hg in the disjointed hyporheic zone in the gold mining area is investigated. Through field investigation, in-situ test, and test analysis, the results show that: (1) the form of mercury in the original stratum where the river water-groundwater hydraulic connection is disconnected is mainly in the residual state, accounting for 77.78% of the total mercury; (2) after the water content increases or the water level changes, the various forms of occurrence in the soil surface layer decrease, and the residual state is still the main form; the main forms of mercury in the sand and pebble layer are diversified, including the residual state, strong organic state and humic acid state; (3) the mercury content in the subsurface zone in winter is higher than that in summer; (4) although the mercury content in groundwater has not been detected, the potential ecological risk of mercury in the disjointed Hyporheic zone near the river in the study area is much higher than the extreme ecological hazard threshold, which has a value of 320. The risk of groundwater pollution caused by mercury during the long-term runoff of the river is higher than that during the flood period. Therefore, relevant departments need to rectify the river as soon as possible, from the source to reduce the ecological risk of heavy metals to groundwater. The results will provide a scientific basis for groundwater control.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192950
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2951: Effect of Rill Development on Slope Erosion
           and Sediment Yield Based on Stereophotogrammetry Technology

    • Authors: Zilin Zuo, Hui Wang, Shuwen Ding, Yijin Wu
      First page: 2951
      Abstract: Rill erosion is an important kind of slope erosion and the main source of sediment. Through simulated rainfall tests, the morphological characteristics of rill were quantified by stereophotogrammetry technology, and the relationship between rill development and sediment yield was studied. The results show that there was a positive correlation between sediment yield and slope and rainfall intensities. With the increase in rainfall duration, sediment yield first increased sharply and then decreased gradually after reaching the peak value, until it reached dynamic stability. With the increase in rainfall intensity and slope, the length, width, and number of rills increased significantly, with a maximum length of 2.58 m and a maximum width and depth of 9.7 and 2.2 cm. The rill density (RD) increased from 16.67% to 62.65%; rill fragmentation degree (RFD) increased from 16.67% to 100.00%; rill complexity (RC) increased from 10.62% to 30.84%, and rill width–depth ratio (RWDR) decreased from 15.82% to 56.28% with the increase in slope from 6° to 15° and rainfall intensity from 2.0 to 3.0 mm/min. There was a good nonlinear relationship between sediment yield and RC and RWDR (R2 = 0.89, NSE = 0.85, n = 10). This study could provide help for the quantification research of rill erosion mechanisms and provide reference for the measurement and scale transformations of soil erosion at different scales.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192951
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2952: Comparison of Two Convergence Criterion in the

    • Authors: Rosalva Mendoza-Ramírez, Rodolfo Silva, Ramón Domínguez-Mora, Eduardo Juan-Diego, Eliseo Carrizosa-Elizondo
      First page: 2952
      Abstract: Stochastic dynamic programming (SDP) is an optimization technique used in the operation of reservoirs for many years. However, being an iterative method requiring considerable computational time, it is important to establish adequate convergence criterion for its most effective use. Based on two previous studies for the optimization of operations in one of the most important multi-reservoir systems in Mexico, this work uses SDP, centred on the interest in the convergence criterion used in the optimization process. In the first trial, following the recommendations in the literature consulted, the difference in the absolute value of two consecutive iterations was taken and compared against a set tolerance value and a discount factor. In the second trial, it was decided to take the squared difference of the two consecutive iterations. In each of the trials, the computational time taken to obtain the optimal operating policy was quantified, along with whether the optimal operating policy was obtained by meeting the convergence criterion or by reaching the maximum number of iterations. With each optimization policy, the operation of the system under study was simulated and four variables were taken as evaluators of the system behaviour. The results showed few differences in the two operation policies but notable differences in the computation time used in the optimization process, as well as in the fulfilment of the convergence criterion.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192952
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2953: Influence of Substrates on the Quality of
           Hermetia Meal for Fish Meal Substitution in Nile Tilapia Oreochromis

    • Authors: Sven Wuertz, Cem Hinrich Pahl, Werner Kloas
      First page: 2953
      Abstract: Commercially produced black soldier flies (Hermetia illucens) represent a promising fish meal substitute, particularly in the context of using agricultural by-products and waste. Here, the culture of Hermetia maggots on five selected substrates (potato protein (P) as a by-product of starch production, rapeseed oil cake (R) from rape oil production, maize silage (M), soybean (S) meal and, as a control, concentrated chicken feed (C)) were evaluated, assessing the growth performance of Hermetia maggots related to the overall production and the nutritional composition of the respective meal. Subsequently, their use as ingredients in aquafeed formulations was evaluated in a feeding trial with juvenile Nile tilapia Oreochromis niloticus, assessing the growth performance of the fish. Substrates used for Hermetia culture significantly affected the growth and development of the maggots, revealing substantial differences in the meal quality. Still, if incorporated in isonitrogenous and isocaloric diets (33% crude protein, 21–22 MJ/kg) replacing 75% of the fishmeal protein in the formulated diets, no significant differences in growth performance of the fish were observed compared to the fishmeal control. As a conclusion, substrates clearly affect the production yield and the composition of maggots. Nevertheless, this can be compensated by feed formulation as demonstrated by the feeding trial.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192953
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2954: A Novel GRA-NARX Model for Water Level
           Prediction of Pumping Stations

    • Authors: Xiaowei Liu, Minghu Ha, Xiaohui Lei, Zhao Zhang
      First page: 2954
      Abstract: It is necessary but difficult to accurately predict the water levels in front of the pumping stations of an open-channel water transfer project because of the complex interactions among hydraulic structures. In this study, a novel GRA-NARX (gray relation analysis—nonlinear auto-regressive exogenous) model is proposed based on a gray relation analysis (GRA) and nonlinear auto-regressive exogenous (NARX) neural network for 2 h ahead for the prediction of water levels in front of pumping stations, in which an improved algorithm of the NARX neural network is used to obtain the optimal combination of the time delay and the hidden neurons number, and GRA is used to reduce the prediction complexity and improve the prediction accuracy by filtering input factors. Then, the sensitivity to changes of the training algorithm is analyzed, and the prediction performance is compared with that of the NARX and GRA-BP (gray relation analysis back-propagation) models. A case study is performed in the Tundian pumping station of the Miyun project, China, to demonstrate the reliability and accuracy of the proposed model. It is revealed that the GRA-NARX-BR (gray relation analysis—nonlinear auto-regressive exogenous—Bayesian regularization) model has higher accuracy than the model based only on a NARX neural network and the GRA-BP model with a correlation coefficient (R) of 0.9856 and a mean absolute error (MAE) of 0.00984 m. The proposed model is effective in predicting the water levels in front of the pumping stations of a complex open-channel water transfer project.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192954
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2955: Effect of Temperature and Acidification on
           Reinjection of Geothermal Water into Sandstone Geothermal Reservoirs:
           Laboratory Study

    • Authors: Haonan Gan, Zhiming Liu, Xiao Wang, Yu Zhang, Yuzhong Liao, Gui Zhao, Jichu Zhao, Zhitao Liu
      First page: 2955
      Abstract: Geothermal reinjection is a new method of geothermal development which can maintain regional geothermal reservoir pressure, and it is conducive to the sustainable development and utilization of geothermal heat. However, geothermal reinjection blockage has always been a problem that restricts geothermal development and utilization, causing geothermal reservoirs, especially the attenuation of sandstone geothermal reservoirs. Considering an example of a typical sandstone geothermal reservoir in Binzhou, in this study, in situ geothermal fluids and borehole cores were collected to conduct automatic rotary reactor experiments under different temperature and acidification conditions in laboratory studies. The chemical compositions of geothermal fluids and core samples before and after the experiment were compared. The results show that both temperature and acid have significant effects on the water–rock interaction. The effect of temperature is mainly shown on mineral solubility, while the effect of acidification is shown in the increased dissolution of calcite and feldspar minerals. Compared with high temperature (65 °C) reinjection conditions, the calcite precipitation at a low temperature (45 °C) is largely reduced, but with larger total mineral volume changes, mainly due to the formation of montmorillonite. Therefore, from the laboratory studies, it is recommended to preform reinjection using a low-temperature fluid, without adding acids.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192955
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2956: Accounting for Climate Change in Extreme Sea
           Level Estimation

    • Authors: Eleanor D’Arcy, Jonathan A. Tawn, Dafni E. Sifnioti
      First page: 2956
      Abstract: Extreme sea level estimates are fundamental for mitigating coastal flooding as they provide insight for defence engineering. As the global climate changes, rising sea levels combined with increases in storm intensity and frequency pose an increasing risk to coastline communities. We present a new method for estimating extreme sea levels that accounts for the effects of climate change on extreme events that are not accounted for by mean sea level trends. We follow a joint probabilities methodology, considering skew surge and peak tides as the only components of sea levels. We model extreme skew surges using a non-stationary generalised Pareto distribution (GPD) with covariates accounting for climate change, seasonality and skew surge–peak tide interaction. We develop methods to efficiently test for extreme skew surge trends across different coastlines and seasons. We illustrate our methods using data from four UK tide gauges and estimate sea level return levels when accounting for these long-term trends.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192956
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2957: Revision of Monoraphid Diatom Genus Platessa
           with Description of Platesiberia gen. nov. from Ancient Lake Baikal

    • Authors: Maxim S. Kulikovskiy, Anton M. Glushchenko, Sergei I. Genkal, Irina V. Kuznetsova, John Patrick Kociolek
      First page: 2957
      Abstract: A new monoraphid diatom genus, Platesiberia gen. nov., is described based on a detailed morphological investigation using light and scanning electron microscopy. The genus is based upon P. rhombicolanceolata Kulikovskiy & Lange-Bertalot and includes Platessa baicalensis Kulikovskiy & Lange-Bertalot, both species previously described from ancient Lake Baikal. Platesiberia gen. nov. is characterized by having biseriate striae on the raphe valves with uniseriate striae on the rapheless valves. Morphology of striae is helpful to distinguish the genus Platesiberia from Platessa and other monoraphid genera, and we provide a comparison of the new Baikalian genus with other freshwater monoraphid groups.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192957
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2958: Elastoplastic Coupled Model of Saturated Soil
           Consolidation under Effective Stress

    • Authors: José Roberto Galaviz-González, Jaime Horta-Rangel, Pedro Limón-Covarrubias, David Avalos-Cueva, Laura Yessenia Cabello-Suárez, Teresa López-Lara, Juan Bosco Hernández-Zaragoza
      First page: 2958
      Abstract: Soil’s consolidation is a geotechnical problem resulting from a stress-transfer process that initiates when the load is applied to the water contained in the soil, producing a reduction in pore water pressure and rearranging the solid particles, and thus causing a decrease in soil volume. Therefore, consolidation is a coupled flow–mechanical problem. Coupled models have been developed to simulate this phenomenon while considering different theories, providing consistent results. This paper presents an elastoplastic coupled model of consolidation under Terzaghi’s effective stress formulated using the equations of transient flow, balance moment, motion, and the critical state model that considered elastoplastic strains. The coupled model algorithm provided fast and easy results due to its flexibility, as it allowed combinations in loading and boundary conditions. Additionally, it considered the external/internal water flow as an inflow or outflow, which modified the pore water pressure and produced changes in the horizontal and vertical displacements. The numerical results obtained showed an appropriate behavior of the consolidation phenomenon, as well as the evolution of the vertical Uy and horizontal Ux isplacements, water pressure pw, volumetric εv and deviatoric εq strain, mean σp and deviatoric σq stress, volumetric variation Δεv, and elastic/plastic behavior of the finite elements while considering the yield surface of the critical state.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192958
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2959: Estimation of Greenhouse-Grown Eggplant
           Evapotranspiration Based on a Crop Coefficient Model

    • Authors: Yinkun Li, Wenzhong Guo, Jiale Wu, Minjie Duan, Yi Yang, Shengyao Liu
      First page: 2959
      Abstract: Accurate estimation of crop evapotranspiration (ETc) is important to determine crop water requirements in greenhouse agriculture and to improve the irrigation water use efficiency. Here, a 3-year (2017–2019) experiment with spring greenhouse-grown eggplant (Solanum melongena L.) was conducted to investigate variation in the crop coefficient (Kc) measured with a weighing lysimeter, adjust Kc based on the local climate (Kc,Adj), and estimate daily ETc using a crop coefficient model. The 3-years mean local Kc (Kc,Loc) were 0.23 ± 0.03, 0.62 ± 0.06, 1.05 ± 0.03 and 0.87 ± 0.03 at the initial, development, mid-season, and end-season stages, respectively. Significant linear correlation was observed between Kc,Adj and Kc,Loc in the 3 years (R2 = 0.873, 0.901, and 0.897 in 2017–2019, respectively). Compared with the FAO-56 recommended Kc value (Kc,FAO), the mean Kc,Adj and Kc,Loc in the 3 years were by 66.3% and 61.8% lower, respectively. The single crop coefficient model accurately estimated daily ETc for greenhouse-grown eggplant. The coefficient of determination (R2), mean absolute error (MAE), root-mean-squared error (RMSE), and index of agreement between measured ETc and that estimated by the single crop coefficient model were 0.94, 0.35 mm‧d−1, 0.26 mm‧d−1, and 0.98, respectively, for the means in 2018 and 2019. Therefore, the crop coefficient method reliably estimated evapotranspiration with adjustment for the actual environment and can serve as a useful tool to improve water use efficiency.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192959
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2960: Streamflow and Sediment Yield Analysis of Two
           Medium-Sized East-Flowing River Basins of India

    • Authors: Nageswara Reddy Nagireddy, Venkata Reddy Keesara, Venkataramana Sridhar, Raghavan Srinivasan
      First page: 2960
      Abstract: With increased demand for water and soil in this Anthropocene era, it is necessary to understand the water balance components and critical source areas of land degradation that lead to soil erosion in agricultural dominant river basins. Two medium-sized east-flowing rivers in India, namely Nagavali and Vamsadhara, play a significant role in supporting water supply and agriculture demands in parts of the Odisha districts of Kalahandi, Koraput and Rayagada, as well as the Andhra Pradesh districts of Srikakulam and Vizianagaram. Floods are more likely in these basins as a result of cyclones and low-pressure depressions in the Bay of Bengal. The water balance components and sediment yield of the Nagavali and Vamsadhara river basins were assessed using a semi-distributed soil and water assessment tool (SWAT) model in this study. The calibrated model performance revealed a high degree of consistency between observed and predicted monthly streamflow and sediment load. The water balance analysis of Nagavali and Vamsadhara river basins showed the evapotranspiration accounted for 63% of the average annual rainfall. SWAT simulated evapotranspiration showed a correlation of 0.78 with FLDAS data. The calibrated SWAT model showed that 26.5% and 49% of watershed area falling under high soil erosion class over Nagavali and Vamsadhara river basins, respectively. These sub watersheds require immediate attention to management practices to improve the soil and water conservation measures.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192960
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2961: Analysis of the Aggregation Characteristics of

    • Authors: Jiandong Li, Yating Song, Wei Zhang, Jiajia Zhu
      First page: 2961
      Abstract: Zhengzhou is located at the dividing point of the middle and lower reaches of the Yellow River, which is the core area of the origin of early Chinese civilization. Studying the influence of the ancient Yellow River distributary on the aggregation of early sites is conducive to understanding the interaction between the water environment and early humans. It will provide strong support for the systematic protection and overall display and utilization of heritage. This research is based on the data of the ancient Yellow River distributary, lakes and swamps, and early settlements. This research adopted a GIS spatial quantitative analysis method to identify early settlements. The early sites in the distributary area of the ancient Yellow River were identified from the aspects of kernel density and cluster complexity. The study analyzed the influence of the evolution of lakes and swamps on the aggregation of sites, and the distance relationship between different levels of settlements and lakes and swamps. The results show that: (1) From the Peiligang period to the Xia and Shang Dynasties, early settlements aggregated in multi-center bands along the west ancient Yellow River distributary. Moreover, the Xingyang–Guangwu trough area was an aggregation area with a large quantity and high degree of complexity. (2) From the Yangshao period to the Xia and Shang Dynasties, the settlement presented the characteristics of distributions around lakes and swamps. From a spatial perspective, the distribution of a centric zone around the Xingyang–Guangwu trough lake and swamp in the west moved to the Xingze lake in the east.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192961
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2962: Modifying Elder’s Longitudinal
           Dispersion Coefficient for Two-Dimensional Solute Mixing Analysis in
           Open-Channel Bends

    • Authors: Kyong Oh Baek, Won Seo
      First page: 2962
      Abstract: Elder’s equation for the longitudinal dispersion coefficient in two-dimensional solute transport analysis cannot be applied to curved channels because the vertical distribution of the longitudinal velocity does not obey the logarithmic law in the bends of an open channel. In this study, a two-dimensional longitudinal dispersion coefficient based on an equation that can appropriately describe the vertical distribution of flow velocity in open-channel bends is derived theoretically. The proposed equations for the vertical velocity distribution and dispersion coefficient are compared and verified with values measured from two different types of open channels, i.e., a laboratory channel and a natural-like channel. The increase in the longitudinal dispersion coefficient based on the difference in the vertical distribution of the flow velocity is evaluated quantitatively. In terms of the longitudinal dispersion coefficient, no significant difference is observed between the observed dispersion coefficient based on the concentration data and the coefficient value calculated using the equation proposed in this study. The dispersion equation proposed in this study can be easily applied to assign the value of the longitudinal dispersion coefficient for the two-dimensional mixing modelling in bends using basic hydraulic factors.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192962
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2963: Nutrient Dynamics and Ecosystem Metabolism of
           Megacity Rivers: Influence of Elevated Nutrient Concentrations in
           Beijing’s Waterways

    • Authors: Meng Zhang, Robert A. Francis, Michael A. Chadwick
      First page: 2963
      Abstract: This study evaluated nutrient flux (nitrate (NO3−), ammonium (NH4+), phosphate (PO43−), and dissolved organic carbon (DOC) at the sediment-water interface and river ecosystem metabolism (REM) to investigate how these ecological functions vary in Beijing’s urban waterways. Three tributaries of the River Beiyun were selected. Water quality varied across the study sites as each receives a mixture of wastewater treatment plant (WWTP) effluents and tributary inflows. A chamber technique was applied where water-specific nutrient concentrations were measured at two exposure times (3 and 10 min). Under the actions of physical and biological processes, NO3− and NH4+ flux was primarily controlled by equilibrium concentration and the N-cycle. However, bioabsorption appeared to regulate DOC flux. Specifically, NO3− flux ranged from −0.31 to +0.30 mg/(m2·s), NH4+ was −0.01 to +0.05 mg/(m2·s), PO43− was −0.01 to +0.01 mg/(m2·s), DOC was −0.04 to +0.13 mg/(m2·s). We applied the nighttime slope regression to estimate gross primary production (GPP) and ecosystem respiration (ER). Except in summer, net ecosystem production (GPP+ER) less than 0 indicated heterotrophic study reaches. Structural equation modelling revealed that nutrient dynamics and water temperature were the primary factors driving REM. Our study provides the needed systems-based understanding of vital ecological processes to improve in-stream management.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192963
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2964: Is Investment Contributing to Competitiveness
           in Nautical Tourism in the Atlantic Area'

    • Authors: Eleonora Santos, Rui Alexandre Castanho, Daniel Meyer
      First page: 2964
      Abstract: The blue economy contributes significantly to the creation of the Atlantic Area’s identity. In addition, the search for outdoor experiences after the COVID-19 lockdown suspensions has renewed the popularity of nautical tourism in this area and in the world. Despite the negative effects of the economic crisis on tourism, evidence suggests that some tourist destinations in the Atlantic area are resilient. Thus, whereas some branches of the blue economy face considerable challenges to increasing competitiveness, others offer opportunities for economic growth and employment. In this context, investment is necessary to lay the foundations for the sustainable development of nautical tourism. However, regarding the role of investment in productivity and competitiveness in the context of crisis, there is no consensus among academics. Thus, we investigate whether the investment contributed to competitiveness in nautical tourism in the Atlantic Area in 2016–2020. We collected data from ORBIS for 29 nautical-tourism companies and performed a quantitative and qualitative narrative analysis of competitiveness indicators, enabling comparisons pre and during crisis. The results highlight the multiplicity of ways in which crisis impacts nautical-tourism firms. The research fills a gap in the literature by investigating the dynamic capabilities of nautical-tourism SMEs in periods of recession, with a special focus on restructuring and competitiveness strategies. Some recommendations are outlined to promote the efficiency of resources and stimulate the competitiveness of companies to allow the regional development of nautical tourism in the territory of the Atlantic area.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192964
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2965: India’s Contribution to Greenhouse Gas
           Emission from Freshwater Ecosystems: A Comprehensive Review

    • Authors: Bipradeep Mondal, Kuldeep Bauddh, Amit Kumar, Nirmali Bordoloi
      First page: 2965
      Abstract: In the modern era, due to urbanization, industrialization, and anthropogenic activities in the catchment, greenhouse gas (GHG; CO2, CH4, and N2O) emissions from freshwater ecosystems received scientific attention because of global warming and future climate impacts. A developing country such as India contributes a huge share (4% of global) of GHGs from its freshwater ecosystems (e.g., rivers, lakes, reservoirs) to the atmosphere. This is the first comprehensive review dealing with the GHG emissions from Indian freshwater bodies. Literature reveals that the majority of GHG from India is emitted from its inland water, with 19% of CH4 flux and 56% of CO2 flux. A large part of India’s gross domestic product (GDP) is manipulated by its rivers. As a matter of fact, 117.8 Tg CO2 year−1 of CO2 is released from its major riverine waters. The potential of GHG emissions from hydropower reservoirs varies between 11–52.9% (mainly CH4 and CO2) because of spatio-temporal variability in the GHG emissions. A significant contribution was also reported from urban lakes, wetlands, and other inland waters. Being a subtropical country, India is one of the global GHG hotspots, having the highest ratio (GHG: GDP) of 1301.79. However, a large portion of India’s freshwater has not been considered yet, and there is a need to account for precise regional carbon budgets. Therefore, in this review, GHG emissions from India’s freshwater bodies, drivers behind GHG emissions (e.g., pH, mean depth, dissolved oxygen, and nutrients), and long-term climatic risks are thoroughly reviewed. Besides research gaps, future directions and mitigation measures are being suggested to provide useful insight into the carbon dynamics (sink/source) and control of GHG emissions.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192965
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2966: Rainfall Threshold for Shallow Landslide
           Triggering Due to Rising Water Table

    • Authors: Antonello Troncone, Luigi Pugliese, Enrico Conte
      First page: 2966
      Abstract: In the present study, a simple-to-use method is proposed for a preliminary prediction of the occurrence of shallow landslides (generally, with a thickness of 1–2 m) due to rainfall. This method can be used when a water table forms within the slope or the existing groundwater level rises due to rain infiltration, resulting in an increase in the pore water pressure. A relationship is also provided to establish when these conditions occur and the method can consequently be used. The proposed method combines a simplified solution to evaluate the change in pore water pressure within the slope due to infiltration, with the simple scheme of infinite slope to calculate a critical value of the pore water pressure that determines the incipient failure condition of the slope. In this way, a threshold curve can be also determined to readily assess whether a rainfall event with expected intensity and duration is capable of causing a slope failure at a given depth, where the initial pore water pressure is known. The method is completely analytical and only requires a few parameters as input data, which in addition can be obtained from conventional tests. A well-documented case study is considered to show how the method can be used for routine applications.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192966
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2967: Analysis of Factors Influencing Wave

    • Authors: Songgui Chen, Hanbao Chen, Cheng Peng, Yina Wang, Yuanye Hu
      First page: 2967
      Abstract: Aiming at the problem of calculating the overtopping of single-slope breakwaters, a mean impact value-backpropagation (MIV-BP) estimation model for predicting overtopping was established. Experimental data from the Tianjin Research Institute of Water Transport Engineering (TIWTE) were utilized to further enrich the dataset of the CLASH project for single-slope wave overtopping discharge. This paper established a comprehensive prediction model based on an ensemble learning average method combination strategy. There are 10 input parameters in the model, including the offshore effective wave height, average wave period, offshore water depth, toe submergence, toe width, slope tangent, armor rock surface roughness factor, crest height with respect to the static water level, wall height with respect to the static water level, and crest width; the output parameter is the mean overtopping discharge. Subsequently, a comparative analysis was conducted between this estimation model, the Chinese standard formula calculation model, and the European Van der Meer formula calculation model. Compared with the two formulas mentioned above, this estimation model’s coefficient of correlation increased by 0.23 and 0.26, respectively. Finally, a weight evaluation analysis of the 10 main factors affecting overtopping was carried out based on a MIV-BP neural network model. In the analysis, a positive correlation was found for factors, such as the wave height, average wave period, and water depth at the structure toe; a negative correlation was found for factors, such as the slope, crest height with respect to the static water level, wall height with respect to the static water level, and crest width. Overall, the results provide a significant basis and reference for optimizing the design of the wave overtopping control.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192967
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2968: Impact of Climate Change on Spatio-Temporal
           Distribution of Glaciers in Western Karakoram Region since 1990: A Case
           Study of Central Karakoram National Park

    • Authors: Muhammad Farhan Ul Moazzam, Jinho Bae, Byung Gul Lee
      First page: 2968
      Abstract: Glaciers in the Upper Indus Basin (UIB) in Pakistan are the major source of water, irrigation, and power production for downstream regions. Global warming has induced a substantial impact on these glaciers. In the present study, Landsat images were utilized to evaluate the glaciers for the period from 1990–2020 in the Central Karakoram National Park (CKNP) region to further correlate with climate parameters. The results reveal that glaciers are retreating and the highest (2.33 km2) and lowest (0.18 km2) recession rates were observed for Biafo and Khurdopin glaciers, respectively. However, a minor advancement has also been observed for the period from 1990–2001. More than 80% of glacier recession was recorded between 2009–2020 because mean summer temperature increased at both Skardu and Gilgit meteorological stations, while precipitation decreased at both stations from 2005–2020. The increase in mean summer temperature and decrease in winter precipitation resulted in glacial retreat, which will lead to water scarcity in the future as well as affect the agriculture sector and hydropower production in downstream areas of the Indus River basin.
      Citation: Water
      PubDate: 2022-09-21
      DOI: 10.3390/w14192968
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2969: Correction: Ikram et al. Biological
           Degradation of the Azo Dye Basic Orange 2 by Escherichia coli: A
           Sustainable and Ecofriendly Approach for the Treatment of Textile
           Wastewater. Water 2022, 14, 2063

    • Authors: Muhammad Ikram, Mohammad Naeem, Muhammad Zahoor, Marlia Mohd Hanafiah, Adeleke Abdulrahman Oyekanmi, Riaz Ullah, Dunia A. Al Farraj, Mohamed S. Elshikh, Ivar Zekker, Naila Gulfam
      First page: 2969
      Abstract: In the original publication [...]
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192969
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2970: A Case Study of the “7-20” Extreme
           Rainfall and Flooding Event in Zhengzhou, Henan Province, China from the
           Perspective of Fragmentation

    • Authors: Zhouying Chen, Feng Kong, Meng Zhang
      First page: 2970
      Abstract: Disaster crisis management is the last defensive line in the face of extreme rainstorm disasters. However, fragmentation undermines the effectiveness of disaster crisis management, and the “7-20” extreme rainfall flooding disaster in Zhengzhou, Henan province, China in 2021 revealed a series of fragmentation problems. The effectiveness of China’s emergency storm flooding management must be seriously considered. We used the “7-20” extreme rainfall event in Zhengzhou, Henan province in China as a case study to perform an inductive, qualitative investigation to understand what fragmentation is and how fragmentation reduces efficacy. Most of the data used for this research were gathered from Chinese official records and online news articles. This study first highlights pertinent studies that have been performed and then presents a comprehensive theoretical framework of fragmentation in catastrophe crisis management, which consists of five aspects: fragmented emergency legislation, emergency organization, information, perception, and services. Second, we have deduced which human responses in the “7-20” event represent the fragmentation issues, and we have examined the detrimental effects of fragmentation in flood crisis management. Finally, suggestions are made for China to increase the effectiveness of disaster crisis management, including encouraging regulatory convergence, matching emergency responsibility and authority, establishing an information-sharing platform, bolstering emergency education and raising risk perception, and changing the dualistic system in disaster crisis management.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192970
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2971: Ecotoxicity of Natural Nanocolloids in Aquatic

    • Authors: Shaohu Ouyang, Yuhao Li, Tong Zheng, Kangying Wu, Xin Wang, Qixing Zhou
      First page: 2971
      Abstract: Nanocolloids (Ncs) are highly dispersed mixtures of nanoscale (1–100 nm) heterogeneous systems, which are ubiquitous in aquatic environments. Ncs are considered a vital pollutant carrier due to their special surface properties and unique hydrodynamic characteristics. They play an essential role in the process of promoting pollutant migration and transformation. In recent years, with the increase in chemicals in the environment and the complexity of environmental pollution, the health threats of Ncs in ecological systems are arousing great concerning. Therefore, recent work to characterize the ecotoxicity of Ncs has focused on the potential environmental health implications, including exploration of toxicity to aquatic organisms from a wide range of the ecosystem food webs. Herein, we summarize the formation, distribution, and characterization of natural Ncs in the marine environments. Moreover, we highlight the adverse impacts of Ncs on representatives of various trophic levels aquatic organisms (e.g., algae, bacteria, invertebrates, and fish). The mechanisms of Ncs ecotoxicity at the cellular level are reviewed, and the remaining unclear points on toxic tools such as oxidative damage and metabolic disorder are presented. We also discuss the research challenges and future developments within the field of ecotoxicity. This study will bridge our knowledge gap on the ecotoxicity of Ncs.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192971
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2972: Using Deep Learning Algorithms for
           Intermittent Streamflow Prediction in the Headwaters of the Colorado
           River, Texas

    • Authors: Farhang Forghanparast, Ghazal Mohammadi
      First page: 2972
      Abstract: Predicting streamflow in intermittent rivers and ephemeral streams (IRES), particularly those in climate hotspots such as the headwaters of the Colorado River in Texas, is a necessity for all planning and management endeavors associated with these ubiquitous and valuable surface water resources. In this study, the performance of three deep learning algorithms, namely Convolutional Neural Networks (CNN), Long Short-Term Memory (LSTM), and Self-Attention LSTM models, were evaluated and compared against a baseline Extreme Learning Machine (ELM) model for monthly streamflow prediction in the headwaters of the Texas Colorado River. The predictive performance of the models was assessed over the entire range of flow as well as for capturing the extreme hydrologic events (no-flow events and extreme floods) using a suite of model evaluation metrics. According to the results, the deep learning algorithms, especially the LSTM-based models, outperformed the ELM with respect to all evaluation metrics and offered overall higher accuracy and better stability (more robustness against overfitting). Unlike its deep learning counterparts, the simpler ELM model struggled to capture important components of the IRES flow time-series and failed to offer accurate estimates of the hydrologic extremes. The LSTM model (K.G.E. > 0.7, R2 > 0.75, and r > 0.85), with better evaluation metrics than the ELM and CNN algorithm, and competitive performance to the SA–LSTM model, was identified as an appropriate, effective, and parsimonious streamflow prediction tool for the headwaters of the Colorado River in Texas.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192972
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2973: A Review of Stakeholder Engagement in
           Integrated River Basin Management

    • Authors: Chow Hock Lim, Hui Ling Wong, Rahmah Elfithri, Fang Yenn Teo
      First page: 2973
      Abstract: To address water-related issues of river pollution, floods, droughts, and ecological water allocations, there is a need for an integrated river basin management (IRBM) plan for the successful management of all the river basins in the country. Stakeholder engagement is one of the important elements for the effective implementation of IRBM. In this study, a systematic bibliometric analysis has been successfully carried out to identify the trends, patterns, and research gaps in the establishment of stakeholder engagement frameworks in IRBM. Three renowned scientific databases were used to quantitatively assess the published literature on stakeholder engagement. The search contributed by providing a clear understanding and mechanisms for an effective stakeholder engagement, thus highlighting the research gap, whereby there is a lack of an effective stakeholder engagement framework for IRBM. Based on the analysis results, it was found that many pieces of literature have been written about the implementation of IRBM, including the importance of stakeholder engagement or participation. However, there is very limited study on how effective stakeholder engagement could be carried out to enhance water management at the river basin level. The findings also recorded that stakeholder engagement can serve as a form of social learning, and leadership plays a significant role in ensuring the effectiveness of stakeholder engagement in IRBM. From the review analysis, it was concluded that further research studies need to be carried out at the river basin level to formulate an effective stakeholder engagement framework for the sustainable management of water.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192973
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2974: Multi-Indicators and Evidence of
           Cytotoxicity—A Case Study of a Stream in Central Brazil

    • Authors: Raylane Pereira Gomes, Thais Reis Oliveira, Aline Rodrigues Gama, José Daniel Gonçalves Vieira, Lilian Carla Carneiro
      First page: 2974
      Abstract: (1) Background: Aquatic systems are important to the community and the environment, requiring careful assessment, including the monitoring of their waters. Cities are usually built close to aquatic systems, which serve as a source of water for the entire population. With the uncontrolled increase in cities, aquatic environments receive a great pollutant load. (2) Methods: In this context, the present study aimed to evaluate water contamination, evaluating multi-indicators, cytotoxicity and mutagenicity and conducting a multivariate analysis on the João Leite stream in central Brazil. (3) Results: It was demonstrated, by means of multi-indicators of water quality, that according to the CONAMA classification, current Brazilian legislation and the purpose of the João Leite stream, the water quality met some parameters (i.e., turbidity, dissolved oxygen, and bacteriological); however, in some samples, the quality was poor or very poor. Samples collected in the rainy season indicated cytotoxicity, probably due to pollutants dragged by the rain into the stream. Based on multivariate and association analysis, we suggest that the João Leite stream presents anthropogenic pollution. (4) Conclusions: This study provides data for the development of prevention, control and environmental management policies. In addition, we demonstrate that the use of multivariate statistical analyses can provide data on water pollution, its source of pollution and the association between pollutants.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192974
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2975: The Impact of Dissolved Organic Matter on
           Arsenic Mobilization from Goethite in the Presence of Silicic Acid and
           Phosphate under Reducing Conditions

    • Authors: Adeleh Aftabtalab, Eduardo Moreno-Jiménez, Jonas Henschel, Sascha Nowak, Jörg Schaller, Klaus-Holger Knorr
      First page: 2975
      Abstract: The release of arsenic (As) adsorbed onto iron oxide (Fe-oxide) surfaces is affected by dissolved organic matter (DOM), phosphate (hereafter referred to as PO4), and silicic acid (H4SiO4). Further, the reductive dissolution of As from Fe-oxide phases is also affected in reduced soils and sediments. Thus, the aim of this study was to understand the adsorption competition and redox-related mechanisms by which DOM affects As mobilization from Fe-oxide in a complex system containing both H4SiO4 and PO4. The results demonstrated that the DOM-driven, microbially mediated As biotransformation, and, thus, mobilization of As significantly increased when both dissolved inorganic H4SiO4 and PO4 were present, as the co-presence of H4SiO4 and PO4 decreased As adsorption sites on Fe-oxides. The availability of DOM in the co-presence of H4SiO4 and PO4 increased the microbial activity in the system by providing more substrates for microbial metabolism, which also decreased the redox potential (reducing conditions) and consumed acidity, causing the pH to increase from 4 to 6.8. In addition, DOM, H4SiO4, and PO4 competed with As for sorption sites on Fe-oxides. The effects of DOM on As mobility by DOM-mediated or -triggered redox reactions were apparently stronger in the co-presence of H4SiO4 and PO4 than DOM competition with arsenate for sorption sites on Fe-oxide alone. These findings advance our understanding of As mobilization processes in natural systems and can provide information for soil As management.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192975
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2976: The Influence of Pretreatment on the
           Efficiency of Electrochemical Processes in Oily Wastewater Treatment

    • Authors: Morana Druskovic, Drazen Vouk, Tomislav Bolanca, Hana Posavcic
      First page: 2976
      Abstract: Wastewater containing oil is becoming a growing problem worldwide due to increasing quantities and existing pollution. The pollutants contained in these effluents, when released into the environment, affect surface and groundwater pollution, endanger human life and health, and pollute the atmosphere. Their sustainable treatment should be cost-effective and meet all requirements to prevent the pollutants from being transferred to the environment or to humans. This study gives a brief overview of some conventional and modern technologies that have been proven in practice for the treatment of oily wastewater. Due to the high concentrations of chemical oxygen demand (COD) and total hydrocarbons (mineral oils) in oily wastewater its treatment is complex, and to achieve optimum treatment conditions and efficiency a combination of different technologies is required. This paper focuses on hybrid electrochemical process combining the electro-Fenton process (EF) using stainless steel (SS), and electrocoagulation (EC) with iron (Fe) and aluminum (Al) electrodes. The influence of the two different types of pretreatment, i.e., pretreatment of the raw wastewater on the overall efficiency of oily wastewater treatment using a hybrid treatment process, which is a combination of AOP and EC, is investigated. Two type of pretreatment were tested, with primary sedimentation and pretreatment of the mixture of raw wastewater and previously generated electrochemical sludge with primary sedimentation. During the applied treatment processes, the concentration of COD, mineral oils, and other elements in the raw and treated wastewater (As, Ca, Cd, Cr, Cu, Ni, Pb, Sn, Zn) and in the generated sludge (K, Ca, Fe, Ti, V, Cr, Mn, Ni, Cu, Zn, Ga, As, Br, Rb, Sr, Y, Zr, Pb, Th) were determined. By combining the primary sedimentation of the raw wastewater with the EF/EC process, a mineral oil removal efficiency of 72% (1.1 mg/L) and COD of 89% (170 mg/L) was achieved. Using primary sedimentation of a mixture of raw wastewater with previously generated sludge as pretreatment and followed by EF/EC treatment, a higher efficiency for mineral oils of 94% (7.6 mg/L) and COD of 98% (43 mg/L) was achieved.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192976
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2977: Genesis and Distribution of Low Fluvial
           Terraces Formed by Holocene Climate Pulses in Brazil

    • Authors: Archimedes Perez Filho, Vinícius B. Moreira, Luca Lämmle, André O. Souza, Bruno A. Torres, Pedro I. C. Aderaldo, Éverton V. Valezio, David O. B. F. Machado, Mateus M. Prebianca, Alysson F. Mazoni, Carolina Zabini, Felipe G. Rubira
      First page: 2977
      Abstract: Low fluvial terraces present azonal spatialization, encompassing several geomorphological compartments and climate zones in Brazil. Their genesis is directly related to river dynamics. When influenced by allogenic forces, such as Holocene climate pulses, it results in channel incision and posterior abandonment of the floodplain. Relatively plain landforms at different altimetric levels identified between the current floodplain and hillslope (low river terraces) are a result of these processes. Previous works using Optically Stimulated Luminescence (OSL) in low terraces of several rivers in Brazil have indicated morpho-chronologic similarities between depositional events, raising the hypothesis of feedbacks and fluvial adjustments relatively simultaneous to Holocene climate events. Considering these dynamics, this study employed OSL to obtain absolute dating information for 114 samples taken from distinct levels of the low river terraces of 30 rivers in Brazil, integrating the database of the IG-UNICAMP laboratory of Geomorphology and Environmental Analysis. Based on the data and statistical analysis (cluster and correlation analysis), this study aimed to identify relationships between different variables which might have controlled spatial homogenous and heterogeneous feedbacks during distinct paleoenvironmental contexts. The proposed methodology tested a fundamental hypothesis of the regional climatic geomorphology, and the results obtained may contribute to future discussions on the relationship between low river terraces and anthropic occupation.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192977
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2978: Response of NDVI and SIF to Meteorological
           Drought in the Yellow River Basin from 2001 to 2020

    • Authors: Jie Li, Mengfei Xi, Ziwu Pan, Zhenzhen Liu, Zhilin He, Fen Qin
      First page: 2978
      Abstract: Understanding the response of vegetation to drought is of great significance to the biodiversity protection of terrestrial ecosystem. Based on the MOD13A2 NDVI, GOSIF, and SPEI data of the Yellow River Basin from 2001 to 2020, this paper used the methods of Theil–Sen median trend analysis, Mann–Kendall significance test, and Pearson correlation analysis to analyze whether the vegetation change trends monitored by MODIS and GOSIF are consistent and their sensitivity to meteorological drought. The results showed that NDVI and SIF increased significantly (p < 0.001) at the rate of 0.496 × 10−2 and 0.345 × 10−2, respectively. The significant improvement area of SIF (66.49%, p < 0.05) is higher than NDVI (50.7%, p < 0.05), and the spatial distribution trend of vegetation growth monitored by NDVI and SIF is consistent. The negative value of SPEI-12 accounts for 65.83%, with obvious periodic changes. The significant positive correlation areas of SIF-SPEI in spring, summer, and autumn (R > 0, p < 0.05) were 7.00%, 28.49%, and 2.28% respectively, which were higher than the significant positive correlation areas of NDVI-SPEI (spring: 1.79%; summer: 20.72%; autumn: 1.13%). SIF responded more strongly to SPEI in summer, and farmland SIF was significantly correlated with SPEI (0.3424, p < 0.01). The results indicate that SIF is more responsive to drought than NDVI. Analyzing the response of vegetation to meteorological drought can provide constructive reference for ecological protection.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192978
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2979: Divalent Lead in Aqueous Solution Changes the
           Surface Morphology of Dolomite and Inhibits Dissolution

    • Authors: Liang Li, Bingjin Wu, Tianyu Guan, Wenhai Wang, Dongwen Wei
      First page: 2979
      Abstract: In groundwater systems, heavy metal ions as solutes (e.g., Pb) can adsorb onto the surface of calcite group rocks and influence their dissolution processes. The dolomite surface was examined using field emission scanning electron microscopy (SEM) and various characterization tools and the changes in water chemistry indexes were reviewed throughout the dissolution process. Pb adsorption on the dolomite surface was evident after 15 days of exposure to 1 mg/L or 50 mg/L divalent Pb salt solutions; the Pb surface phase was mainly PbCO3 with an octahedral ligand structure. SEM images show that dolomite in divalent Pb salt solutions can lead to the surface morphology exhibiting curved dissolution steps. In the closed system with Pb (1 mg/L), the total alkalinity and conductivity of the solution were lower than in the Pb-free system, and the pH difference was slight, indicating that the dibasic metal ion Pb inhibited the dolomite dissolution process. Combined with the composition of the final solid phase, it is suggested that the dolomite surface preferentially adsorbs Pb2+ on the active sites and that the newly grown solid phase is PbCO3 possesses an octahedral ligand structure. Part of the surface-active site is occupied, resulting in a change in the dissolution profile, and thus preventing further development of the dissolution profile. Ultimately, the entire dolomite surface area is prevented from dissolution. The results of this study suggest that Pb2+ may be an effective inhibitor of dolomite dissolution and may help to further refine the geological carbon sink.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192979
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2980: Flood Uncertainty Estimation Using Deep

    • Authors: Priyanka Chaudhary, João P. Leitão, Tabea Donauer, Stefano D’Aronco, Nathanaël Perraudin, Guillaume Obozinski, Fernando Perez-Cruz, Konrad Schindler, Jan Dirk Wegner, Stefania Russo
      First page: 2980
      Abstract: We propose a probabilistic deep learning approach for the prediction of maximum water depth hazard maps at high spatial resolutions, which assigns well-calibrated uncertainty estimates to every predicted water depth. Efficient, accurate, and trustworthy methods for urban flood management have become increasingly important due to higher rainfall intensity caused by climate change, the expansion of cities, and changes in land use. While physically based flood models can provide reliable forecasts for water depth at every location of a catchment, their high computational burden is hindering their application to large urban areas at high spatial resolution. While deep learning models have been used to address this issue, a disadvantage is that they are often perceived as “black-box” models and are overconfident about their predictions, therefore decreasing their reliability. Our deep learning model learns the underlying phenomena a priori from simulated hydrodynamic data, obviating the need for manual parameter setting for every new rainfall event at test time. The only inputs needed at the test time are a rainfall forecast and parameters of the terrain such as a digital elevation model to predict the maximum water depth with uncertainty estimates for complete rainfall events. We validate the accuracy and generalisation capabilities of our approach through experiments on a dataset consisting of catchments within Switzerland and Portugal and 18 rainfall patterns. Our method produces flood hazard maps at 1 m resolution and achieves mean absolute errors as low as 21 cm for extreme flood cases with water above 1 m. Most importantly, we demonstrate that our approach is able to provide an uncertainty estimate for every water depth within the predicted hazard map, thus increasing the model’s trustworthiness during flooding events.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192980
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2981: Evaluation of the Synergy Degree of Watershed
           Collaborative Governance: A Case Study of Taihu Basin, China

    • Authors: Xiaofeng Huang, Weijian Qiu, Xingying Dai, Wenwen Hua
      First page: 2981
      Abstract: Owing to the publicity and externality of watershed governance, collaborative governance among cities has become an inevitable choice to improve watershed governance performance and promote sustainable development of watersheds. Existing studies have provided many enlightenment on promoting watershed collaborative governance (WCG), while most of them investigated WCG from single or several dimensions with scanty quantitative empirical studies. Against this background, this study aims to establish a comprehensive WCG research framework involving multiple phases and diverse actors to empirically measure the synergy degree of WCG. Specifically, this study constructs a WCG index system composed of resource investment, open cooperation, and performance supervision subsystems that involves actors of government, enterprise, and the public. Using the complex system synergy model, an empirical analysis is performed to evaluate the synergy degree of Taihu Basin collaborative governance among and within cities in Jiangsu province, China during 2014–2020. The results reveal that the Tai Basin collaborative governance among cities was still in the run-in adaptation stage, which was primarily constrained by the discrete open cooperation subsystems among cities. The synergy degree of Taihu Basin collaborative governance within cities presented significant differences. Several targeted implications are proposed according to the results. This study provides a comprehensive index system for synergy degree measurement of WCG and could offer effective guidance for policymakers to design effective strategies for improving WCG performance.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192981
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2982: Study on Change of the Glacier Mass Balance
           and Its Response to Extreme Climate of Urumqi Glacier No.1 in Tianshan
           Mountains in Recent 41 Years

    • Authors: Jiajia Peng, Liping Xu, Zhongqin Li, Puchen Chen, Yutian Luo, Cui Cao
      First page: 2982
      Abstract: Glaciers are susceptible indicators of climate change and crucial parts of the world’s water cycle. In the context of global warming, we took the Urumqi Glacier No.1 (UG1) as an example, which is situated at the source of the Urumqi River on the northern slope of the Tianshan Mountains, Xinjiang, combined with the climate data of Daxigou Meteorological Station from 1980 to 2020, and the change of glacier mass balance and its response to extreme climate are discussed. The results suggest that the glacier mass balance of UG1 showed a downward trend over the studied 41-year period, and the mass loss increased. The cumulative glacier mass balance value was −19,776 mm w.e., and the average annual value was −482 mm w.e.a−1. The Mann-Kendall trend test showed that the change point occurred around 1994, and the mass balance of UG1 became more negative after 1994. In the same period, the changing mass balance trend of UG1 was not the same in different seasons. The inter-annual variation of summer mass balance was drastic, showing a marked downward trend; the inter-annual change of winter mass balance was small, showing a slight uptrend. The changing of extreme climate indices where UG1 is located showed that only TX90p and TX10p changed observably from 1980 to 2020, and the extreme precipitation indices changed evidently and had been on the rise. The changing trend of extreme climate indices indicated that the temperature was rising, the warming was significant, and the precipitation was increasing. During 1980–2020, the glacier mass balance was substantially correlated with the extreme temperature indices (TX90p, TXx) but not with the extreme precipitation indices. Analyzing on a seasonal scale, the summer mass balance was memorably correlated with the extreme temperature indices (TX90p, TX10p, TXx), and the correlation coefficient between winter mass balance and the extreme precipitation index R95p and winter precipitation was in the range 0.36~0.40 (p < 0.05). According to the correlation between glacier mass balance and extreme climate indices, the summer mass balance was mainly affected by temperature, and the winter mass balance was affected primarily by precipitation.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192982
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2983: Feasibility Study of Atmospheric Water
           Harvesting Augmented through Evaporative Cooling

    • Authors: Lesedi Kgatla, Brian Gidudu, Evans M. Nkhalambayausi Chirwa
      First page: 2983
      Abstract: The water harvesting potential of atmospheric water generators (AWGs) in high-altitude semiarid regions can be diminutive relative to the water generation capacity. Operational parameters for the dehumidification process can be augmented to increase atmospheric water in the defined zone available for harvesting. In this paper, the feasibility of augmenting the microclimates of AWGs at the point of air extraction through an evaporative cooling system (ECS) was investigated. Water yield and capacity utilisation were measured from two AWGs piloted on a plant in Ga-Rankuwa, South Africa. This was implemented between December 2019 and May 2021. The study revealed that although the ECS did impact the operating parameters through decreasing temperature and increasing relative humidity (p < 0.05), variance in water yield was not significant (p > 0.05). Capacity utilisation of the AWGs remained below 50% after augmentation. Cooling efficiency of the ECS ranged between 1.4–74.5%. Energy expenditures of 0.926 kWh/L and 0.576 kWh/L for AWGs 1 and 2 were required under pristine conditions, respectively. Under the modified conditions, energy expenditure decreased to 0.855 kWh/L for AWG 1, but increased/L to 0.676 kWh for AWG 2. ECS is deduced to not be a feasible intervention for augmenting water harvesting potential for AWGs in this semiarid zone.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192983
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2984: Flood Inundation Modeling by Integrating
           HEC–RAS and Satellite Imagery: A Case Study of the Indus River Basin

    • Authors: Afzal, Ali, Nazeer, Khan, Waqas, Aslam, Cheema, Nadeem, Saddique, Muzammil, Shah
      First page: 2984
      Abstract: Floods are brutal, catastrophic natural hazards which affect most human beings in terms of economy and life loss, especially in the large river basins worldwide. The Indus River basin is considered as one of the world’s large river basins, comprising several major tributaries, and has experienced severe floods in its history. There is currently no proper early flood warning system for the Indus River which can help administrative authorities cope with such natural hazards. Hence, it is necessary to develop an early flood warning system by integrating a hydrodynamic model, in situ information, and satellite imagery. This study used Hydrologic Engineering Center–River Analysis System (HEC–RAS) to predict river dynamics under extreme flow events and inundation modeling. The calibration and validation of the HEC–RAS v5 model was performed for 2010 and 2015 flood events, respectively. Manning’s roughness coefficient (n) values were extracted using the land use information of the rivers and floodplains. Multiple combinations of n values were used and optimized in the simulation process for the rivers and floodplains. The Landsat 5 Thematic Mapper (TM), Landsat 8 Operational Land Imager (OLI), Moderate Resolution Imaging Spectroradiometer (MODIS) MOD09A1, and MOD09GA products were used in the analysis. The Normalized Difference Water Index (NDWI), Modified NDWI1 (MNDWI1), and MNDWI2, were applied for the delineation of water bodies, and the output of all indices were blended to produce standard flood maps for accurate assessment of the HEC–RAS-based simulated flood extent. The optimized n values for rivers and floodplains were 0.055 and 0.06, respectively, with significant satisfaction of statistical parameters, indicating good agreement between simulated and observed flood extents. The HEC–RAS v5 model integrated with satellite imagery can be further used for early flood warnings in the central part of the Indus River basin.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192984
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2985: Ecosystem Service Value Response to Different
           Irrigation and Drainage Practices in a Land Development Project in the
           Yellow River Delta

    • Authors: Chen, Jiang
      First page: 2985
      Abstract: The potential for development of saline land is enormous; the concept has recently attracted great scientific attention regarding its use and development. It is especially crucial to consider the issue of ecological balance when carrying out large-scale land remediation in the Yellow River Delta region since the saline land there is rich in resources and is also typically an ecologically delicate area. In order to quantitatively estimate the value of ecosystem services under various irrigation and drainage modes, this paper uses an undeveloped land development project in the Yellow River Delta as an example, simulates five different irrigation and drainage modes, and combines the market value method and the calculation method of factor equivalents. A quantitative estimation of the ecosystem service value under different irrigation and drainage modes is carried out, exploring the impact of different irrigation and drainage modes on the ecosystem from the perspective of ecosystem service value. The findings revealed that while the “Pipeline irrigation + concealed pipe” irrigation and drainage model increased the area of cultivated land by 4.04 km2, the overall ecological value increased by only Renminbi (RMB) 6.707 × 106. It is clear that only an increase in the area of cultivated land will not increase the ecological value as a whole. Through comparison, it is found that the ecological value of ‘Pipeline irrigation + open ditch’ irrigation and drainage pattern increases the most, which is RMB 28.405 × 106. It can increase the area of cultivated land and protect the ecological benefits to a greater extent, which can better meet the requirements of the current comprehensive development. The study’s findings can serve as a foundation for the sustainable development of the area and the scientific selection of development in ecologically vulnerable coastal areas.
      Citation: Water
      PubDate: 2022-09-22
      DOI: 10.3390/w14192985
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2986: The Multi-Objective Optimization of Low-Impact
           Development Facilities in Shallow Mountainous Areas Using Genetic

    • Authors: Huiyi Sun, Yuxiang Dong, Yue Lai, Xuanyin Li, Xiaoyu Ge, Chensong Lin
      First page: 2986
      Abstract: From the perspective of whole-area sponge city construction, it is important to scientifically determine the layout plan of LID facilities for controlling urban rainfall and flooding problems, given the topographical features and rainfall runoff characteristics of shallow urban mountainous areas. Current research on the optimization of low-impact development facilities is limited to the central urban area level, with insufficient research on shallow urban mountainous areas, and there is great uncertainty in the layout of LID facilities when multiple objectives are considered. Therefore, this paper applied a genetic algorithm (NSGA-II) to optimize the layout scheme of LID facilities. Multiple objectives of the peak runoff abatement rate, cost, and land area were selected as the optimization objectives, and the optimized results were ranked using the EWM-TOPSIS and VCWM-TOPSIS methods. The 2nd Hebei Provincial Garden Flower Expo (Qinhuangdao) Park was used as the research object for the optimization design. The results showed that, under the premise of water safety, the lowest cost priority was given to the LID facility with a 15.49% share, 99.43% peak runoff reduction rate, and a cost of CNY 1.215 × 107; the lowest area priority was given to the LID facility with a 15.25% share, 99.42% peak runoff reduction rate, and a cost of CNY 1.267 × 107. The EWM-TOPSIS method was also used to obtain the best optimized solution with 16.18% LID facilities, 99.64% peak runoff abatement rate, and a cost of CNY 1.26 × 107, and the worst optimized solution with 12.55% LID facilities, 97.91% peak runoff abatement rate, and a cost of CNY 1.061 × 107. The decision results under different decision-maker preferences were obtained by the VCWM-TOPSIS method. This study showed that the combination of a genetic algorithm and TOPSIS can optimize the layout of LID facilities in shallow mountainous areas more scientifically and efficiently compared to the actual construction plan for building a sponge city.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14192986
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2987: Enhanced Adsorption of Rhodamine B on Biomass
           of Cypress/False Cypress (Chamaecyparis lawsoniana) Fruit: Optimization
           and Kinetic Study

    • Authors: Salma Gul, Hajera Gul, Maria Gul, Rozina Khattak, Gul Rukh, Muhammad Sufaid Khan, Hani Amir Aouissi
      First page: 2987
      Abstract: Many industries use various dyes to beautify their products and discharge the waste into the water without proper treatment. Such wastewater is not only dangerous for aquatic life but it is also toxic to human life and can cause numerous problems, such as skin diseases, and some dyes are carcinogenic or even mutagenic as well. Rhodamine-B (RhB) is one of those synthetic organic dyes which is widely used in textile, paper making, leather manufacturing, stained glass work, cosmetics, and many other industries owing to its high tinting strength, high stability, and bright colour. Therefore, it is essential to either remove or reduce its concentration before releasing it into aquatic streams, as well as to minimize or control the cause of several diseases. Several physical and chemical methods have been used for the removal of different dyes from wastewater; nevertheless, adsorption is one of the best techniques used for the removal of dyes due to its high efficiency and low cost. In this regard, we used Chamaecyparis lawsoniana (C. lawsoniana) fruit as a bio-adsorbent for the removal of RhB from an aqueous solution. An 85.42% dye adsorption was achieved at optimized conditions (pH 2, 40 ppm initial dye concentration, 105 min, and 50 mg adsorbent). Adsorption occurs by pseudo-second-order kinetics, according to kinetic studies. Several samples from various sources, including tap water, distilled water, river water, and filtered river water, were tested for RhB removal, and the study revealed good results even in river water. Thus, C. lawsoniana fruit can be used for its real-world application.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14192987
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2988: Effects of Temperature on Growth, Molting,
           Feed Intake, and Energy Metabolism of Individually Cultured Juvenile Mud
           Crab Scylla paramamosain in the Recirculating Aquaculture System

    • Authors: Jiahao Liu, Ce Shi, Yangfang Ye, Zhen Ma, Changkao Mu, Zhiming Ren, Qingyang Wu, Chunlin Wang
      First page: 2988
      Abstract: An eight-week experiment was conducted to investigate the effects of temperature (20, 25, 30, and 35 °C) on growth performance, feed intake, energy metabolism, antioxidant capacity, and the stress response of juvenile Scylla paramamosain in a recirculating aquaculture system. The results showed that the survival rate of the 35 °C group was 80.36 ± 5.92%, significantly lower than that of the other three groups (100%). The high molt frequency of mud crabs was observed in high-temperature groups, accompanied by a higher ecdysone level and ecdysone receptor gene expression but lower molt inhibitory hormone gene expression. However, the molt increment (73.58 ± 2.18%), food intake, and feed conversion efficiency showed a parabolic trend, with the lowest value found in the 35 °C group. Oxygen consumption rate and ammonia excretion rate increased with the increasing temperature, and oxygen-nitrogen ratio, lactic acid, triglyceride, total cholesterol, glucose, and cortisol peaked at 35 °C. Temperature also significantly affected the antioxidant system of S. paramamosain. Crabs in the 25 °C and 30 °C had a significantly higher total antioxidant capacity and lower malondialdehyde compared with the 35 °C group (p < 0.05). Although the high temperature promoted molting, it decreased the feeding rate and growth performance, leading to oxidative stress and functional hypoxia. The quadratic function model demonstrated the optimum temperature for the specific growth rate of juvenile S. paramamosain was 28.5–29.7 °C.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14192988
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2989: Site Investigation and Remediation of
           Sulfate-Contaminated Groundwater Using Integrated Hydraulic Capture

    • Authors: Nianqing Zhou, Shuaishuai Lu, Yi Cai, Shan Zhao
      First page: 2989
      Abstract: Inorganic pollution is widespread in groundwater, and sulfate pollution is one of the important types, which has an important impact on the ecological environment and human health. Elevated concentrations of sulfate ion pollutants often come from the sewage discharge of chemical plants. This study takes a sulfate-contaminated site in Dongying City, Shandong Province, China, as the research object. Nine boreholes were arranged along the sewage discharge ditches in the site to collect and analyze soil samples and groundwater samples in layers. The concentration of pollutants and the change with depths were determined; the maximum concentration of sulfate ion was 10,330 mg L−1 in groundwater, and the maximum pollution depth was no more than 8 m. A hydraulic barrier was carried out to cut off the pollution sources. Based on a comprehensive understanding of the hydrogeological conditions and pollution degree of the site, the hydraulic capture technique was used to control the water pumping and injection volume, so that the scope of the pollution plume was gradually reduced. The pumping wells were arranged in the polluted area, and the water injection wells were arranged at the outer edge of the pollution zone. According to the calculation of the single well water inflow and influence radius, 28 pumping wells and 66 water injection wells were needed to be arranged on the site. The treatment process was divided into four stages according to the following steps: water pumping, water injection, stoppage of water injection, stoppage of water pumping, collecting water samples after the water level recovered, and the completion stage of treatment. The above process was repeated twice. Chemical precipitation was employed in the last step. The results of the remediation showed that the sulfate concentrations in 54 percent of the samples decreased significantly to less than 100 mg L−1, and the rest were between 100 and 200 mg L−1 after the treatment process. Two pumping wells with serious pollution were selected as long-term monitoring wells, and two-year continuous monitoring results showed that sulfate concentrations in the monitoring wells ranged from 110 to 220 mg L−1, indicating that integrated groundwater remediation techniques are more effective and more reliable than one single technique.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14192989
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2990: Flexible Electroflotocoagulation Reactor: New
           Design and Testing in Treatment of Real Surface Water

    • Authors: Sergiu Vasilie, Liviu-Danut Vitan, Constantin-Adrian Tudoran, Florica Manea
      First page: 2990
      Abstract: A novel continuous and flexible electroflotocoagulation (EFC) reactor was built using concentric cylindrical Al and Fe electrodes, which can be operated either as anodes or cathodes linked to a DC connection. The reactor was operationally assessed related to various cell configurations that assured the required stages of coagulant dosage, mixing, reaction, and settling or flotation. The effects of several design variables and operational parameters (such as the electrode position that determines the reactor configuration, current density (i), flow rate (F), and the electrode area-treated volume ratio (Sel/V)) on the specific energy consumption versus the aluminum dose and charge loading rate were investigated. The most energy-efficient cell configuration using an aluminum anode and iron cathode was tested for the treatment of surface water (Bega river, Timisoara city, Romania) rich in hydrophobic natural organic matter (8.3 mg C∙L−1 and specific UV absorbance parameter of 3.9 L∙m−1∙mg−1) and with a high turbidity of 92 NTU, under flood conditions. The best results that assured 97% turbidity removal, 87% for absorbance recorded at 254 nm, and 60% for DOC removal, through enhanced electroflotocoagulation, were achieved for an operational current density of 10 A∙m−2 with specific energy and electrode consumption of 0.1 kW h∙m−3 and 0.017 kg Al∙m−3, respectively.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14192990
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2991: Analysis of Surface Water Quality and
           Sediments Content on Danube Basin in Djerdap-Iron Gate Protected Areas

    • Authors: Francisc Popescu, Milan Trumić, Adrian Eugen Cioabla, Bogdana Vujić, Virgil Stoica, Maja Trumić, Carmen Opris, Grozdanka Bogdanović, Gavrila Trif-Tordai
      First page: 2991
      Abstract: As water is essential to life and is an indispensable resource for ecosystems and their services and for nearly all human activities, the goal of this research was to evaluate the surface water quality of the Danube as it passes through the Romania–Serbia border in the nature reservations Djerdap and Iron Gate. The study aimed to assess the oxygen regime, nutrients and heavy metals contamination of the surface waters of the Danube on a length of about 240 km, between Bazias and Iron Gate II. Reference sampling and analytical methods (UV-VIS and AAS) were deployed to reach this goal. In addition, sediments were analyzed through back scattered SEM-EDAX for the elemental analysis of the sediment surface. Results obtained show a low environmental impact of heavy metals, while the Danube’s oxygen regime is under stress due to nutrients’ (nitrites and orthophosphates) significant concentration in the Danube surface water in the analyzed sector. Our approach can be applied to other water bodies in the area, to increase available scientific data together with societal awareness of the Danube’s environmental risks.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14192991
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2992: Differences in Fish Abundance in Rivers under
           the Influence of Open-Pit Gold Mining in the Santiago-Cayapas Watershed,
           Esmeraldas, Ecuador

    • Authors: Monsalve, Prado, Ortiz, Toulkeridis
      First page: 2992
      Abstract: Illegal gold mining is on the rise in the tropical Andes. The Santiago-Cayapas watershed is located in the north of the Pacific basin of Ecuador, in the Chocó biogeographical region It is recognized for its high biodiversity, as 62 fish species have been described in the area, and because it contains two of the largest protected areas in the Pacific coast of Ecuador: the mangroves of the Cayapas and Mataje Rivers and the Cotacachi-Cayapas Ecological Reserve. Open-pit gold mining has been described in the area since 2006 and most mining fronts operate illegally and lack any environmental control. Heavy-metal concentrations and fish communities were studied in streams that drain active and abandoned mines, in larger rivers located downstream of the mined areas and in control sites without mining activities. Open-pit mining causes a reduction of dissolved oxygen concentrations and an increase of water temperature, turbidity, and concentrations of Al, Cr, Co, Cu, Fe, Mn, and V. Fish abundance decreased in streams that drain active mines, however, metrics of taxonomic diversity remain unchanged among the study sites. The response of fish communities to open-pit gold mining was complex and driven by the pollution tolerance of each species, the presence of specific adaptions to turbid waters, and changes in the fishing pressure as locals avoid fishing activities in mined areas. Finally, streams that drain abandoned mines showed chemical characteristics, metal concentrations, and fish communities that were similar to control sites, but maintained higher water temperatures than control sites.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14192992
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2993: New Stage–Discharge Relationship for
           Triangular Broad-Crested Weirs

    • Authors: Alessio Nicosia, Francesco Giuseppe Carollo, Costanza Di Stefano, Vito Ferro
      First page: 2993
      Abstract: Simple hydraulic structures, such as weirs, allow measuring flow discharge by using the upstream flow depth and a stage–discharge relationship. In this relationship, a discharge coefficient is introduced to correct all the effects neglected in the derivation (viscosity, surface tension, velocity head in the approach channel, flow turbulence, non-uniform velocity profile, and streamline curvature due to weir contraction). In this paper, the dimensional analysis and the incomplete self-similarity theory are used to investigate the outflow process of triangular broad-crested weirs, characterized by different values of the ratio between crest height p and channel width B, and to theoretically deduce a new stage–discharge relationship. A new theoretical stage–discharge relationship is suggested for the free-flow condition, and it is tested using experimental data available in the literature for the hydraulic condition p/B > 0. The obtained stage–discharge equation, characterized by low errors in discharge estimate, is useful for laboratory and field investigations. Finally, specific analysis for the triangular broad-crested weirs with p/B > 0 was developed to modify the stage–discharge relationship obtained for the case p/B = 0. This specific stage–discharge relationship allows to reduce the errors, which are generally less than ±5%, in the estimate of discharge for triangular broad-crested weirs with p/B > 0 and is also applicable for the case p/B = 0.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14192993
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2994: First Application of the AMBI Index to the
           Macrobenthic Soft-Bottom Community of Terra Nova Bay (Ross Sea, Southern

    • Authors: Cristina Munari, Angel Borja, Cinzia Corinaldesi, Eugenio Rastelli, Marco Lo Martire, Valentina Pitacco, Michele Mistri
      First page: 2994
      Abstract: The assemblages of marine benthic organisms and sediment characteristics were investigated in the coastal area between the Mario Zucchelli Antarctic Research Station and Adelie Cove in Terra Nova Bay (Ross Sea, Southern Ocean) during the 2015 summer season. Sediment samples were taken from 11 stations at depths between 25 and 140 m. The dominance of sand characterised sites, and the biochemical composition of the sedimentary organic matter resulted in very variable between the different sites. A total of 142 taxa were identified, with Annelida (68 taxa) and Arthropoda (35 taxa) constituting the main macrobenthic groups. The benthic community at deeper stations showed higher species richness and lower dominance compared to the shallower stations. For the first time in Antarctica, we also investigated the response of the AZTI’s Marine Biotic Index (AMBI) to the organic gradient. Of the 142 taxa found, 97 were not listed in the AMBI library, and we were able to assign as many as 88 taxa to an ecological group. All of these new species were added to the new AMBI species list. AMBI showed a good response to the organic gradient.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14192994
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2995: Dispersal and Survival of Captive-Reared
           Threatened Fishes in a Tonle Sap Lake Reserve

    • Authors: Teresa Campbell, Peng Bun Ngor, Bunyeth Chan, Jackman C. Eschenroeder, Elizabeth Everest, Sudeep Chandra, Seila Chea, Kakada Pin, Samol Chhuoy, Soksan Chhorn, Sothearith Soem, Mecta Sup, Chheng Phen, Hoy Sreynov, Thay Somony, Chheana Chhut, Zeb S. Hogan
      First page: 2995
      Abstract: The Tonle Sap Lake in Cambodia supports several species of threatened megafish and contains one of the largest networks of freshwater fish reserves in the world. Despite these traits, this system remains understudied in terms of its utility for endangered fish conservation and restoration. This study was the first of a series of planned fish releases designed to test the effectiveness of conservation supplementation programs in the Tonle Sap Lake. In March 2022 (during the dry season), 1582 captive-reared fishes, including 1538 striped catfish Pangasianodon hypopthalmus, 42 giant barb Catlocarpio siamensis, and two Mekong giant catfish Pangasianodon gigas, were tagged and released into a 986-hectare fish reserve to assess post-release dispersal and survival. Brightly colored external tags with unique identification numbers were used to facilitate tag returns. A high-profile release event was held to raise awareness about the activity, bringing attention to the importance of fish reserves and endangered species conservation, and disseminating information about the research and tag return and reward program. This, in concert with other efforts, served to be an important education and outreach tool and increased tag return rates. We found that mortality from fishing was rapid and very high. Nineteen percent of released fishes were recaptured in the first 2 days after the fish release, and 46% were recaptured by day 83 after the release, indicating intense fishing pressure on the Tonle Sap Lake fisheries. Eighty percent of recaptured fishes were caught in stationary gill nets, most within 10 km of the release site. Fishing mortality rates were independent of fish size or source (pond-reared or cage-reared). Environmental DNA (eDNA) was found to be capable of detecting each of these species’ presence in the water at the release site and could prove to be a useful tool for endangered species monitoring and restoration. Future research should explore alternative release timing, release location, and other methods of increasing post-release survival. Ultimately, underlying sources of mortality, especially fishing, will need to be addressed for conservation supplementation programs to succeed in the Tonle Sap Lake. Conservation supplementation should not be viewed as a substitute for more fundamental conservation measures, such as maintenance of environmental flows, preservation of ecological connectivity, and science-based fisheries management.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14192995
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2996: Prediction of Multi-Scale Meteorological
           Drought Characteristics over the Yangtze River Basin Based on CMIP6

    • Authors: Jiaxin Yu, Han Zhou, Jiejun Huang, Yanbin Yuan
      First page: 2996
      Abstract: Drought is a common and greatly influential natural disaster, yet its reliable estimation and prediction remain a challenge. The object of this paper is to investigate the spatiotemporal evolution of drought in the Yangtze River basin. The multi-time scale drought characteristics were analyzed based on 19 models and 3 emission scenarios of CMIP6. The results show that the CMIP6 model generally has moisture deviation in the Yangtze River basin, but the accuracy has been improved after correction and ensemble. The drought conditions in the near future (2030–2059) of the Yangtze River basin will be more severe than those in the historical period (1981–2010), with the drought intensity increasing by 7.47%, 18.24%, 18.34%, and 41.48% in the order of 1-month, 3-month, 6-month, and 12-month scales, but it will be alleviated in the far future (2070–2099) to 5.97%, 11.86%, −4.09%, and −8.97% of the historical period, respectively. The 1-month scale drought events are few, and the spatial heterogeneity is strong under different scenarios; areas of high frequency of the 3-month, 6-month, and 12-month scale drought events shift from the upper and middle reaches, middle and lower reaches in the historical period to the southwestern part of the entire basin in the future, and the harm of drought in these regions is also higher. The Yangtze River basin will get wetter, and the variability will increase in the future. The larger the time scale is, the more intense the change will be, with the 12-month scale varying about three times as much as the 1-month scale.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14192996
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2997: An Overview of Light-Mediated Impact of
           Graphene Oxide on Algae: Photo-Transform, Toxicity and Mechanism

    • Authors: Yang Gao, Li Chen, Shenghua Cheng, Ling Zhu, Lijuan Liu, Peihuan Wen, Letao Zhou, Wenjing Xue, Songhua Lu, Wei Zhang, Lean Zhou, Shiquan Sun
      First page: 2997
      Abstract: Due to the unique chemical and physical properties, graphene-based nanomaterials are increasingly being introduced into various scientific fields. They all play very important roles in different fields and are widely used. Graphene oxide (GO) is one of the most popular and representative carbon nanomaterials; scientists have great research interest in it. When carbon nanomaterials such as GO are released into the aquatic environment, their physicochemical properties will be influenced by natural light, resulting in the potential change in toxic effects on aquatic organisms. Algae, as a typical aquatic organism, is extensively regarded as a model microorganism to assess the biotoxicity of nanomaterials. In this review, we overview the light-mediated impact of GO on algae. We summarize the photo-transformation of GO under different illumination conditions and the effect of illumination on the physicochemical properties of GO. Then, we combined metabolomics, genotoxicity, and proteomics with standard toxicity assays (cell division, membrane permeability, oxidative stress, photosynthesis, cellular ultrastructure, and so on) to compare native and environmentally transformed GO induction toxicological mechanisms. By correlating lights, physicochemical properties, and biotoxicity, this review is valuable for environmental fate assessments on graphene-based nanoparticles, providing a theoretical basis and support for evaluating the potential ecological health and environmental risks of graphene-based nanoparticles in real natural water environments.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14192997
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2998: Intensity-Duration-Frequency Curve for Extreme
           Rainfall Event Characterization, in the High Tropical Andes

    • Authors: Diego Escobar-González, Mélany S. Singaña-Chasi , Juan González-Vergara , Bolívar Erazo , Miguel Zambrano, Darwin Acosta , Marcos Villacís , Mario Guallpa , Braulio Lahuatte, Diego H. Peluffo-Ordóñez
      First page: 2998
      Abstract: In fields such as hydrology, meteorology, and civil engineering, the study of extreme precipitation events is useful to prevent rainfall related disasters. A widely-used practice to address such a problem is by using statistical inferences about precipitation intensity, duration and frequency (IDF). Despite of its great usefulness, the selection of the adequate data and methodology to characterize precipitation’s IDF in the urban area of high-altitude Andean cities remains an open issue for practitioners and decision makers. In this sense, the present paper develops an approach to schematically build the IDF curves for a sub-basin of the study case Andean city, Quito–Ecuador. The here-used data holds information from 12 meteorological stations. Then, the IDF curves are obtained by using both a parametrization followed by a Gamma distribution and a 3-parameter cumulative distribution function, also called mnp. Finally, the curve-fitting process is estimated numerically by adjusting the Sherman equation. Results (average R2=0.9) demonstrated that the framework is well-suited for the high-altitude regime. As a noticeable outcome, a novel spatial interpolation-based analysis is introduced, which enabled the identification of extreme rainfall events according to its duration.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14192998
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 2999: Variation in Spectral Characteristics of
           Dissolved Organic Matter and Its Relationship with Phytoplankton of
           Eutrophic Shallow Lakes in Spring and Summer

    • Authors: Zhang, Yang, Liao, Hu, Yu, Yuan, Li, Cui
      First page: 2999
      Abstract: The compositional characteristics of dissolved organic matter (DOM) have important implications for lake water quality and aquatic ecology. Seasonal changes of dissolved organic matter (DOM) as well as phytoplankton abundance and composition in Shahu Lake from April to July were characterized by three-dimensional fluorescence spectroscopy (3DEEMs) combined with parallel factor (PARAFAC) analysis. The relationship between the response of components of the DOM and phytoplankton abundance were explored via Pearson correlation and redundancy analysis (RDA) in the overlying water. The results showed that the DOM was composed mainly of tryptophan-like (C2+C4), fulvic-acid-like (C3), humic-acid-like (C1), and tyrosine-like (C5) compounds that accounted for 44.47%, 20.18%, 20.04%, and 15.31%, respectively, of the DOM. The DOM was derived from both endogenous and terrestrial sources. With seasonal changes, endogenous DOM produced by phytoplankton growth and metabolism gradually increased. In spring and summer (April–July), Chl-a concentrations were significantly correlated with C3 (p < 0.01) and C5 (p < 0.05). The concentration of protein-like fractions (C2+C4, C5) were correlated with Cyanobacteria abundance, and the concentrations of humic-like component content (C1, C3) were correlated with the abundance of Xanthophyta, Chlorophyta, and Cryptophytes. Overall, phytoplankton density and Chl-a content increased by 125% and 197%, respectively, and the abundance of C3 and C5 in the DOM increased by 7.7% and 22.15% in parallel. Thus, seasonal phytoplankton growth had an important influence on the composition of the DOM.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14192999
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3000: A Modified Hydrologic Model Algorithm Based on
           Integrating Graph Theory and GIS Database

    • Authors: Chia-Cheng Shiu, Tzuping Chiang, Chih-Chung Chung
      First page: 3000
      Abstract: Ensuring high quantity and quality of water for humans is becoming more important because of the water supply risks in extreme climates. With increasing urbanization, urban water resource management is becoming increasingly important. The hydrologic analysis of water supply pipelines can help decision-makers understand water pressure, flow rate, water quality, and possible leakages, extending feasible strategies for sustainable development and smart cities. In this study, an improved urban hydrologic analysis model was built by integrating the connectivity of graph theory and the geographic information system (GIS) database. The Neihu Division of the Taipei Water Department in Taiwan was taken as an example to explain the proposed process and method, and 15,131 confluence data items were used to analyze the differences between the proposed method and WaterGEMS. The results show that of the total head parameters, 72% had zero differences, 28% had a difference of less than 1 m, and about 99% of the confluences had a water pressure difference of less than 1 m. The comparison of 120 on-site water pressure measurements showed that about 85% of the confluences had an error of less than 20%. The above results demonstrated the applicability of the proposed method for water resource management on similar scales and its benefit for the development of smart cities.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14193000
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3001: The Premise of Interdisciplinarity and Its
           Actual Absence—A Bibliometric Analysis of Publications on Heavy

    • Authors: Guido Sieber, Benjaming Freudenberg, Leon Netzel, Torsten Claus Schmidt, Frederik Brandenstein
      First page: 3001
      Abstract: Working together across disciplinary boundaries is considered to be the gold standard for conducting meaningful research tackling complex problems. As this is the nature of many issues concerning water, one would assume interdisciplinarity as being a widespread trait of water research. To review this assumption, we chose to conduct an analysis of research output considering issues of stormwater management and heavy precipitation, as reflected in the meta-information for more than 300,000 documents supplied by Elsevier’s Scopus literature database. For this purpose, we applied a bibliometric measure based on Jaccard similarity determining the level of interdisciplinary cooperation between different fields of research on the topic above. Contrary to interdisciplinarity being depicted as highly desirable, it turns out to be a relatively marginal phenomenon, only growing slowly over the last 50 years.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14193001
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3002: Groundwater Quality for Irrigation Purposes in
           the Diass Horst System in Senegal

    • Authors: Ousmane Coly Diouf, Hameth Khassim Sarr, Mathias Diedhiou, Lutz Weihermüller, Ndeye Maguette Dieng, Seynabou Cissé Faye, Harry Vereecken, Serigne Faye
      First page: 3002
      Abstract: Due to surface water scarcity and variability in rainwater events in the Thies region, Senegal, farmers mostly rely on groundwater resources to improve yield production, although water quality in the hydrosystem and its suitability may be an issue. The objective of this study is to evaluate suitability of the Maastrichtian and Paleocene aquifers located the central western part of Senegal in the Thies region for irrigation purposes. For this purpose, chemical analyses were carried out on the major ions on the Maastrichtian and Paleocene aquifers through a network of 62 sample locations (39 from the Maastrichtian and 23 from the Paleocene) sampled in June 2019. Different water suitability assessment indices were used to evaluate the potential for irrigation, including sodium absorption ration (SAR), percentage of sodium (Na%), permeability index, Kelly ratio (RK), and salinity potential (SP) together with Wilcox and USSL diagrams as methods. The results indicate, that the Ca-Mg-HCO3 water type is dominant in the Maastrichtian aquifer, while in the Paleocene aquifer, HCO3-Ca-Mg and Cl-Ca-Mg are the main water types. The combination of these computed index values indicates that the percentage of suitable water for irrigation purposes accounts for 89.7% and 86.9% of the samples for the Maastrichtian and the Paleocene aquifers, respectively. On the other hand, water samples unsuitable for irrigation purposes range between only 10.3% and 13.1% for the two aquifers.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14193002
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3003: Discrimination of Chemical Oxygen Demand
           Pollution in Surface Water Based on Visible Near-Infrared Spectroscopy

    • Authors: Xueqin Han, Xiaoyan Chen, Jinfang Ma, Jiaze Chen, Baiheng Xie, Wenhua Yin, Yanyan Yang, Wenchao Jia, Danping Xie, Furong Huang
      First page: 3003
      Abstract: Chemical oxygen demand (COD) is one of the indicators used to monitor the level of pollution in surface water. To recycle agricultural water resources, it is crucial to monitor, in a timely manner, whether COD in surface water exceeds the agricultural water control standard. A diagnostic model of surface water pollution was developed using visible near-infrared spectroscopy (Vis-NIR) combined with partial least squares discriminant analysis (PLS–DA). A total of 127 surface water samples were collected from Guangzhou, Guangdong, China. The COD content was measured using the potassium dichromate method. The spectra of the surface water samples were recorded using a Vis-NIR spectrometer, and the spectral data were pre-processed using four different methods. To improve the accuracy and simplicity of the model, the synthetic minority oversampling technique (SMOTE) and the competitive adaptive reweighted sampling (CARS) algorithm were used to enhance model performance. The best PLS–DA model achieved an accuracy of 88%, and the SMOTE–PLS–DA model had an accuracy of 94%. The SMOTE algorithm could improve the accuracy of the model despite the sampling imbalance. The CARS–SMOTE–PLS–DA model achieved 97% accuracy, and the CARS band selection technique improved the simplicity and accuracy of the discrimination model. The CARS–SMOTE–PLS–DA model improved the discrimination accuracy by 9% over that of the PLS–DA model. This method can not only save human and material resources but is also a new way for real-time online discrimination of COD in surface water.
      Citation: Water
      PubDate: 2022-09-23
      DOI: 10.3390/w14193003
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3004: Assessment of the Effects of COVID-19 Pandemic
           Stay-at-Home Measures on Potable Water Consumption Patterns, Location, and
           Financial Impacts for Water Utilities in Colombian Cities

    • Authors: Catalina Ortiz, Camilo Salcedo, Juan Saldarriaga
      First page: 3004
      Abstract: Several studies suggest that social distancing measures due to the COVID-19 pandemic have affected the water sector, specifically regarding its demand and supply. Given the importance of hygiene practices, this effect is heightened by the role that potable water availability has in tackling the spread of the virus. This study aimed to assess the impact of the pandemic on the water consumption patterns and location in four Colombian cities known for their important commercial, industrial, academic, and touristic features. Results exhibit diverse diminishing water consumption trends alongside COVID-19 because of different attributes of the cities (e.g., size, environmental, socioeconomic, and sociocultural characteristics). For instance, the touristic case study has been the most affected because of travel restrictions, with an average commercial demand drop of 32%. In contrast, industrial case studies have had a rapid recovery in water demand, with average industrial drops of 11–14% compared to 20–25% in non-industrial cities. These water demand changes do not affect only the operation of water utilities, but also their finances. Economic losses were estimated at 3.7%, 2.4%, and 6.4% of the expected incomes for the first 14 months of the pandemic for the case studies in this paper. Under a changing environment, understanding these changes and challenges is fundamental for ensuring that water systems are resilient in any unexpected situation.
      Citation: Water
      PubDate: 2022-09-24
      DOI: 10.3390/w14193004
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3005: Contrasting Management and Fates of Two Sister
           Lakes: Great Salt Lake (USA) and Lake Urmia (Iran)

    • Authors: Wayne A. Wurtsbaugh, Somayeh Sima
      First page: 3005
      Abstract: Many saline lakes throughout the world are shrinking due to overexploitation of water in their drainage basins. Among them are two of the world’s largest saline lakes, the U.S.A.’s Great Salt Lake, and Iran’s Lake Urmia. Here we provide a comparative analysis of the desiccation of these two lakes that provides insights on management decisions that may help save them and that are relevant to saline lake management worldwide. Great Salt Lake and Lake Urmia were once remarkably similar in size, depth, salinity, and geographic setting. High rates of population growth in both basins have fueled a demand for irrigated agriculture and other uses. In the Great Salt Lake basin, this development began in the late 1800′s and is continuing. The lake’s volume has decreased by 67%, with 75% of the loss driven by water development and 25% by a millennial drought which may portend the start of global climate change impacts. This has greatly increased salinities to 180 g L−1 stressing the invertebrates in the lake on which birds depend. Only 1% of people in the basin are employed in agriculture; thus, reducing the demand for irrigation development. Population densities in the Urmia basin are double those of the Great Salt Lake basin, and 28% of people are employed in agriculture. These demographics have led to a rapid increase in reservoir construction since 2000 and the subsequent loss of 87% of Lake Urmia’s volume. The water development of Lake Urmia was later, but much faster than that of Great Salt Lake, causing Urmia’s salinity to increase from 190 to over 350 g L−1 in just 20 years, with subsequent severe ecological decline. Dust storms from the exposed lakebeds of both systems threaten the health of the surrounding populations. To save these lakes and others will require: (1) transparent and collaborative involvement with local interest groups; (2) shifts away from an agricultural-based economy to one based on manufacturing and services; (3) consideration of the diverse ecosystem services of the lakes including mineral extraction, recreation, bird habitats in surrounding wetlands, and dust control.
      Citation: Water
      PubDate: 2022-09-24
      DOI: 10.3390/w14193005
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3006: Trend Test for Hydrological and Climatic Time
           Series Considering the Interaction of Trend and Autocorrelations

    • Authors: Saiyan Liu, Yangyang Xie, Hongyuan Fang, Huihua Du, Pengcheng Xu
      First page: 3006
      Abstract: The Mann–Kendall (MK) test was widely used to detect significant trends in hydrologic and climate time series (HCTS), but it cannot deal with significant autocorrelations in HCTS. To solve this problem, the modified MK (MMK) test and the over-whitening (OW) operation were successively proposed. However, there are still limitations for these two methods, especially for the OW operation. When an HCTS has unknown interaction scenarios of trends and autocorrelations, it is obviously unclear which of these two methods will perform better in the trend test. Additionally, the trend test is always accompanied by an autocorrelations test. In the dual test, it is also unknown how the significance level affects the accuracy of the trend test. To address these issues, this study first proposes a strategy of adding an outer loop to modify the OW-operation-based trend test. Then, two simulation experiments are designed to evaluate the performances of MMK-test-based and OW-operation-based methods, and the influence of the significance level on the trend test is analyzed. Moreover, six HCTSs in the Huaihe River basin are taken as examples to examine the consistence and difference of trend test results of these two methods. Results show that: (1) previous OW operations still have the risk of misjudging trends in the presence of significant autocorrelations, and the proposed strategy is necessary and effective to modify the OW operation; (2) these two methods are similar in the accuracy of the trend test results, but they may also produce opposite results when determining whether a significant trend is a pseudo trend or not; and (3) at a given significance level α, the accuracy rates of two methods are always less than 1-α, and the accuracy rate of the trend test tends to decrease for short HCTSs and increase for long HCTSs as the significance level decreases. This study would provide a new perspective for the trend test of HCTS based on the MK test.
      Citation: Water
      PubDate: 2022-09-24
      DOI: 10.3390/w14193006
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3007: Health Assessment of the Waterway from
           Chongqing to Yibin in the Upper Yangtze River, China

    • Authors: Pinjian Li, Jing Xue, Wei Xia, Tianhong Li
      First page: 3007
      Abstract: Ecological waterway construction and waterway health protection have become a trend and requirement of waterway development worldwide. How to assess the health status of a waterway is a fundamental concern for waterway sustainable development. This study established a comprehensive framework for health assessment of the waterway from Chongqing to Yibin in the upper reach of the Yangtze River, focusing on the coordinated development of river functions or services including navigation, flood discharge, sediment transport, water supply, self-purification, ecology, and recreation. This framework consists of a hierarchical indicator system, a weight determination method with analytic hierarchy process (AHP), an assessment model considering cask short board effect, and a sensitive analysis method. The waterway health in this river section in the periods 2016–2017 and 2018–2020 were assessed. The results showed that the river functions of navigation, flood discharge, water supply, ecology, and recreation had improved, while sediment transport had deteriorated from “Fair” to “Poor”, and self-purification remained at “Excellent” condition. The overall health of the waterway from Chongqing to Yibin has improved but remained in a “Fair” state during 2016–2020, at roughly the same healthy state as the other three waterways in the middle, middle-lower, and lower reaches. The results are conducive to understanding the health status of the whole Yangtze River waterway. They can serve as an important reference for ecological protection and development of high quality in the Yangtze River basin.
      Citation: Water
      PubDate: 2022-09-24
      DOI: 10.3390/w14193007
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3008: Geochemical Composition, Source and
           Geothermometry of Thermal Water in the Bugok Area, South Korea

    • Authors: Chanho Jeong, Yujin Lee, Yongcheon Lee, Sangwon Ahn, Keisuke Nagao
      First page: 3008
      Abstract: Thermal water from the hot springs around Bugok, South Korea, has the highest discharge temperature (78 °C), and the source of that heat is of primary interest. The key 3He/4He ratio runs along a single air-mixing line between the mantle and the crust, with the latter accounting for 97.0–97.3%. This suggests that the thermal source is radioactive decay in granodiorite, rock that intruded beneath the Cetaceous era sedimentary rock. Thermal water containing Na–HCO3 (SO4) evolved geochemically from stream water and groundwater containing Ca–HCO3. With respect to δ34S, there are two types of thermal water: low temperature with low δ34S (−3.00~+1.00‰), and high temperature with high δ34S (+4.60~+15.0‰), which is enriched by the kinetic fractionation of H2S. The thermal water samples, except for a few, reached partial chemical equilibrium. The thermal reservoir temperatures were estimated as in the range of 90–126 °C by the K–Mg geothermometer of Giggenbach and the thermodynamic equilibrium of quartz and muscovite. This study suggests a conceptual model for the formation of geothermal water, including the thermal reservoir in the Bugok area.
      Citation: Water
      PubDate: 2022-09-24
      DOI: 10.3390/w14193008
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3009: The Impacts of Chlorine and Disinfection
           Byproducts on Antibiotic-Resistant Bacteria (ARB) and Their Conjugative

    • Authors: Cen Kong, Xin He, Meiting Guo, Shunjun Ma, Bin Xu, Yulin Tang
      First page: 3009
      Abstract: Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are emerging contaminants leading to severe worldwide health problems. Chlorination, a widely used procedure, was extensively explored as one of the main methods to remove ARB and ARGs in recent years. In this study, to enrich the analyses of chlorination, several comprehensive effects of the chlorine disinfection system on ARB and their conjugative transfer ability were explored. The results presented that the low dose of chlorine (<3-log inactivation rate) had little influence on the survival of bacteria in terms of their capacity for conjugative transfer and antibiotic resistance. The high dose of chlorine (>3-log inactivation rate) triggered cell membrane changes, with little influence on the bacteria in terms of their antibiotic resistance. However, their capacity for conjugative transfer sharply decreased. Minor consumption of chloramphenicol was achieved with the chlorine dose applied in the disinfection system. Monochloroacetonitrile (MCAN) had limited effects on the frequency of conjugative transfer, indicating that the existence of MCAN would not aggravate the dissemination of ARGs by conjugative transfer. The overall impacts of the chlorine disinfection system with different containments on antibiotic resistance need further investigation.
      Citation: Water
      PubDate: 2022-09-24
      DOI: 10.3390/w14193009
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3010: Dual-Functional Nanostructures for
           Purification of Water in Severe Conditions from Heavy Metals and E. coli

    • Authors: Abdulaziz Abdulrahman AMulla, Osama Saber, Mohamed Farouk Ezzeldin, Mahmoud Mohamed Berekaa, Waleed I. M. El-Azab
      First page: 3010
      Abstract: Because of industrial water, many groundwater sources and other water bodies have a strongly acidic medium. Increased bacterial resistance against multiple antibiotics is one of the main challenges for the scientific society, especially those commonly found in wastewater. Special requirements and materials are needed to work with these severe conditions and treat this kind of water. In this trend, nanolayered structures were prepared and modified in different ways to obtain an optimum material for removing different kinds of heavy metals from water in severe conditions, alongside purifying water from a Gram-negative bacteria (E. coli), which is an indication for fecal pollution. An ultrasonic technique effectively achieved this dual target by producing nanolayered structures looking like nanotapes with dimensions of 25 nm. The maximum removal percentages of the heavy metals studied (i.e., iron (Fe), copper (Cu), chromium (Cr), nickel (Ni), and manganese (Mn)) were 85%, 79%, 68%, 63%, and 61%, respectively for one prepared structure. In addition, this nanostructure showed higher antimicrobial activity against the most common coliform bacterium, E. coli (inhibition zone up to 18.5 mm). This study introduces dual-functional material for removing different kinds of heavy metals from water in severe conditions and for treating wastewater for Gram-negative bacteria (E. coli).
      Citation: Water
      PubDate: 2022-09-24
      DOI: 10.3390/w14193010
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3011: Applying the C-Factor of the RUSLE Model to
           Improve the Prediction of Suspended Sediment Concentration Using Smart
           Data-Driven Models

    • Authors: Haniyeh Asadi, Mohammad T. Dastorani, Khabat Khosravi, Roy C. Sidle
      First page: 3011
      Abstract: The accurate forecasts and estimations of the amount of sediment transported by rivers are critical concerns in water resource management and soil and water conservation. The identification of appropriate and applicable models or improvements in existing approaches is needed to accurately estimate the suspended sediment concentration (SSC). In recent decades, the utilization of intelligent models has substantially improved SSC estimation. The identification of beneficial and proper input parameters can greatly improve the performance of these smart models. In this regard, we assessed the C-factor of the revised universal soil loss equation (RUSLE) as a new input along with hydrological variables for modeling SSC. Four data-driven models (feed-forward neural network (FFNN); support vector regression (SVR); adaptive neuro-fuzzy inference system (ANFIS); and radial basis function (RBF)) were applied in the Boostan Dam Watershed, Iran. The cross-correlation function (CCF) and partial autocorrelation function (PAFC) approaches were applied to determine the effective lag times of the flow rate and suspended sediment, respectively. Additionally, several input scenarios were constructed, and finally, the best input combination and model were identified through trial and error and standard statistics (coefficient of determination (R2); root mean square error (RMSE); mean absolute error (MAE); and Nash–Sutcliffe efficiency coefficient (NS)). Our findings revealed that using the C-factor can considerably improve model efficiency. The best input scenario in which the C-factor was combined with hydrological data improved the NS by 16.4%, 21.4%, 0.17.5%, and 23.2% for SVR, ANFIS, FFNN, and RBF models, respectively, compared with the models using only hydrological inputs. Additionally, a comparison among the different models showed that the SVR model had about 4.1%, 13.7%, and 23.3% (based on the NS metric) higher accuracy than ANFIS, FFNN, and RBF for SSC estimation, respectively. Thus, the SVR model using hydrological data along with the C-factor can be a cost-effective and promising tool in SSC prediction at the watershed scale.
      Citation: Water
      PubDate: 2022-09-24
      DOI: 10.3390/w14193011
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3012: Influence of Data Length on the Determination
           of Data Adjustment Parameters in Conceptual Hydrological Modeling: A Case
           Study Using the Xinanjiang Model

    • Authors: Thandar Tun Zin, Minjiao Lu
      First page: 3012
      Abstract: Minimum data length is vital to guarantee accuracy in hydrological analysis. In practice, it is sometimes determined by the experiences of hydrologists, leading the selection of the acceptable minimum data length to an arguable issue among hydrologists. Therefore, this study aims to investigate the impact of data length on parameter estimation and hydrological model performance, especially for data-scarce regions. Using four primary datasets from river basins in Japan and USA, subsets were generated from a 28-year dataset and used to estimate data adjustment parameters based on the aridity index approach to improve the parameter estimation. The influence of their length on hydrological analysis is evaluated using the Xinanjiang (XAJ) model; also, the effectiveness of outlier removal on the parameter estimation is checked using regression analysis. Here, we present the estimation of the most acceptable minimum data length in parameter estimation for assessing the XAJ model and the effectiveness of parameter adjustment by removing the outliers in observed datasets. The results show that between 10-year to 13-year datasets are generally sufficient for the robust estimate of the most acceptable minimum data length in the XAJ model. Moreover, removing outliers can improve parameter estimation in all study basins.
      Citation: Water
      PubDate: 2022-09-24
      DOI: 10.3390/w14193012
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3013: Comparative Evaluation of Five Hydrological
           Models in a Large-Scale and Tropical River Basin

    • Authors: Leandro Ávila, Reinaldo Silveira, André Campos, Nathalli Rogiski, José Gonçalves, Arlan Scortegagna, Camila Freita, Cássia Aver, Fernando Fan
      First page: 3013
      Abstract: Hydrological modeling is an important tool for water resources management, providing a feasible solution to represent the main hydrological processes and predict future streamflow regimes. The literature presents a set of hydrological models commonly used to represent the rainfall-runoff process in watersheds with different meteorological and geomorphological characteristics. The response of such models could differ significantly for a single precipitation event, given the uncertainties associated with the input data, parameters, and model structure. In this way, a correct hydrological representation of a watershed should include the evaluation of different hydrological models. This study explores the use and performance of five hydrological models to represent daily streamflow regimes at six hydropower plants located in the Tocantins river basin (Brazil). The adopted models include the GR4J, HYMOD, HBV, SMAP, and MGB-IPH. The evaluation of each model was elaborated considering the calibration (2014–2019) and validation period (2005–2010) using observed data of precipitation and climatological variables. Deterministic metrics and statistical tests were used to measure the performance of each model. For the calibration stage, results show that all models achieved a satisfactory performance with NSE values greater than 0.6. For the validation stage, only the MGB-IPH model present a good performance with NSE values greater than 0.7. A bias correction procedure were applied to correct the simulated data of conceptual models. However, the statistical tests exposed that only the MGB-IPH model could preserve the main statistical properties of the observed data. Thus, this study discusses and presents some limitations of the lumped model to represent daily streamflows in large-scale river basins (>50,000 km2).
      Citation: Water
      PubDate: 2022-09-25
      DOI: 10.3390/w14193013
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3014: Adsorption of Remazol Brilliant Violet-5R from
           Aqueous Solution Using Sugarcane Bagasse as Biosorbent: Kinetic and
           Thermodynamic Studies

    • Authors: Toheed Ullah, Hajera Gul, Fatima Khitab, Rozina Khattak, Yousaf Ali, Shagufta Rasool, Muhammad Sufaid Khan, Ivar Zekker
      First page: 3014
      Abstract: Sugarcane bagasse is an inexpensive and eco-friendly natural biosorbent for the removal of various organic pollutants. The adsorption of Remazol Brilliant Violet-5R (RBV-5R) dye on sugarcane bagasse (SCB) was studied. Biosorbent was characterized using EDX and FTIR. The effect of various experimental parameters, such as pH, biosorbent dosage, initial dye concentration, contact time, adsorption with shaking and without shaking, and the temperature, was optimized. At pH 6, maximum biosorption of 92.22% was achieved using 0.15 g of SCB. The equilibrium was attained within 30–40 min for the removal of RBV-5R. The initial dye concentration of 10 µg/mL was determined as an optimum concentration for maximum removal of RBV-5R at 30 °C. Langmuir and Freundlich adsorption isotherms were applied, and it was found that the biosorption of RBV-5R follows Freundlich adsorption isotherms. Kinetic studies were also carried out and it was found that the proposed method followed the pseudo-second-order kinetic model (R2 = 0.98). From desorption study, it was found that maximum desorption in the increasing order was obtained using ethanol, methanol, and 0.2 M sodium hydroxide (NaOH). The biosorption study was applied to actual textile waste effluent to pave way for the practical usage of this technology on a larger scale and the results were found effective.
      Citation: Water
      PubDate: 2022-09-25
      DOI: 10.3390/w14193014
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3015: Impact of Environmental Conditions and
           Seasonality on Ecosystem Transpiration and Evapotranspiration Partitioning
           (T/ET Ratio) of Pure European Beech Forest

    • Authors: Peter Petrík, Ina Zavadilová, Ladislav Šigut, Natalia Kowalska, Anja Petek-Petrik, Justyna Szatniewska, Georg Jocher, Marian Pavelka
      First page: 3015
      Abstract: Partitioning of evapotranspiration (ET) into transpiration (T) and residual evaporation (E) is a challenging but important task in order to assess the dynamics of increasingly scarce water resources in forest ecosystems. The T/ET ratio has been linked to the ecosystem water use efficiency of temperate forests, and thus is an important index for understanding utilization of water resources under global climate change. We used concurrent sap flow and eddy-covariance measurements to quantify the ET partitioning in pure European beech forest during the 2019–2020 period. The sap flow data were upscaled to stand level T and combined with stand level ET to calculate the T/ET ratio. We analysed intra-annual dynamics, the effect of seasonality and the impact of meteorological conditions on T, ET and T/ET. Annual T/ET of a pure European beech ecosystem was 0.48, falling at the lower end of reported global T/ET values for forest ecosystems. T/ET showed significant seasonal differences throughout spring (T/ET = 0.28), summer (T/ET = 0.62) and autumn (T/ET = 0.35). Air temperature (R2 = 0.45–0.63), VPD (R2 = 0.47–0.6) and PAR (R2 = 0.32–0.63) affected the daily dynamics of T, ET and T/ET; however, soil water content (SWC) had no significant effect. Mature European beech trees showed more anisohydric behaviour and relatively stable T/ET, even under decreasing SWC. The results improve the understanding of ecosystem scale T, ET and T/ET intra-annual dynamics and environmental constraints in anisohydric mature European beech.
      Citation: Water
      PubDate: 2022-09-25
      DOI: 10.3390/w14193015
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3016: Pig Slaughterhouse Wastewater: Medium Culture
           for Microalgae Biomass Generation as Raw Material in Biofuel Industries

    • Authors: Johanna Medrano-Barboza, Kevin Herrera-Rengifo, Alberto Aguirre-Bravo, José Rubén Ramírez-Iglesias, Rosalía Rodríguez, Victoria Morales
      First page: 3016
      Abstract: Microalgae are photosynthetic microorganisms with high lipid content, capable of degrading nutrients from wastewater. In this research, two strains of microalgae, Scenedesmus sp. and Chlorella vulgaris were cultivated in sterilized pig slaughterhouse wastewater using outdoor flat photobioreactors. Cell growth, total lipids, free fatty acids (FFA), fatty acid methyl esters (FAME) and physicochemical parameters of wastewater were measured. The results indicated that pig slaughterhouse wastewater is adequate to grow these species of microalgae, obtaining a higher biomass growth for Scenedesmus sp. compared to Chlorella vulgaris (0.41 g/L vs. 0.2 g/L); additionally, these species can be used in bioremediation processes due to the nutrient removal achieved in terms of Total Nitrogen (TN), Total Phosphorous (TP) and Total Organic Carbon (TOC). Methylcyclohexane, chloroform: methanol (1:2) and ethyl acetate had better yield of lipids and FFA. The percentages of FAMEs from FFA were in the range of 52.5–89.5 wt% for Scenedesmus sp. and for Chlorella vulgaris from 52–80.5 wt%. Although the values of lipids, FFA and FAME are below of the range reported by other authors, the use of this type of wastewater as culture medium for the two species cannot be ruled out for lipid extraction in biofuel production.
      Citation: Water
      PubDate: 2022-09-25
      DOI: 10.3390/w14193016
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3017: Identifying Cost-Effective Low-Impact
           Development (LID) under Climate Change: A Multi-Objective Optimization

    • Authors: Yasir Abduljaleel, Yonas Demissie
      First page: 3017
      Abstract: Low-impact development (LID) is increasingly used to reduce stormwater’s quality and quantity impacts associated with climate change and increased urbanization. However, due to the significant variations in their efficiencies and site-specific requirements, an optimal combination of different LIDs is required to benefit from their full potential. In this article, the multi-objective genetic algorithm (MOGA) was coupled with the stormwater management model (SWMM) to identify both hydrological and cost-effective LIDs combinations within a large urban watershed. MOGA iteratively optimizes the types, sizes, and locations of different LIDs using a combined cost- and runoff-related objective function under both past and future stormwater conditions. The infiltration trench (IT), rain barrel (RB), rain gardens (RG), bioretention (BR), and permeable pavement were used as potential LIDs since they are common in our study area—the city of Renton, WA, USA. The city is currently adapting different LIDs to mitigate the recent increase in stormwater system failures and flooding. The results from our study showed that the optimum combination of LIDs in the city could reduce the peak flow and total runoff volume by up to 62.25% and 80% for past storms and by13% and 29% for future storms, respectively. The findings and methodologies presented in this study are expected to contribute to the ongoing efforts to improve the performance of large-scale implementations of LIDs.
      Citation: Water
      PubDate: 2022-09-25
      DOI: 10.3390/w14193017
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3018: Research on Hydraulics and River Dynamics

    • Authors: Vlassios Hrissanthou
      First page: 3018
      Abstract: River engineering is one of the most important subjects in hydraulic engineering [...]
      Citation: Water
      PubDate: 2022-09-26
      DOI: 10.3390/w14193018
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3019: The Role of Hydrographic Mapping in the Study
           of Emerging Aquatic Insects on the Landscape Scale

    • Authors: Rémi Gerber, Benjamin Bergerot, Romain Georges, Jean-Marc Roussel, Christophe Piscart
      First page: 3019
      Abstract: Emerging aquatic insects constitute one of the main biological flows connecting aquatic and terrestrial ecosystems. In a landscape, there are many sources of emergence, which vary in space and time. Thus, they must be clearly defined when studying the inland dispersal of aquatic insects. In this study, we defined five types of hydrographic networks (including or not including ponds and ditches) on the basis of cartographic data of varying degrees of detail (from OpenStreetMap to field map) in order to explain the abundance of aquatic insects. We sampled Ephemeroptera, Plecoptera, Trichoptera, and Megaloptera (ETPM) with 64 sticky traps homogeneously covering a 75 ha agricultural landscape. The abundance of aquatic insects is logically better explained by the hydrographic networks recorded directly in the field than by the reference network, which is incomplete (OpenStreetMap). The results show that, depending on the sampling period, not all water bodies in the landscape are necessarily sources of emergence. To our knowledge, the issue of defining the sources of emerging aquatic insects has never been raised. Based on a practical example, this short note shows that, by refining the hydrographic network to better match the sources of emergence, the explanatory power of inland aquatic insect abundance can be greatly improved.
      Citation: Water
      PubDate: 2022-09-26
      DOI: 10.3390/w14193019
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3020: A Novel Slug Heat Test Theoretical and Indoor
           Model Research for Determining Thermal Property Parameters of Aquifers and
           Rock-Soil Skeletons

    • Authors: Zhao, Wei, Rong, Dong, Zhang, Huang, Wang
      First page: 3020
      Abstract: As important parameters for characterizing heat transfer, thermal property parameters of aquifers and rock-soil skeletons have important research significance in the development and utilization of geothermal resources. The slug heat test is inspired by the slug test, and the heat is instantaneously excited in the test well so as to change the temperature of test section in the test well instantaneously. Based on the thermal radial convection-dispersion theory and the principle of heat conservation, the theoretical model of the slug heat test is established, and the model is solved by Laplace transform and inverse transform to obtain multiple sets of standard curves under different conditions. The slug heat tests were conducted in the indoor model, the slug heat test data under different hydrodynamic conditions were fitted with the standard curves and the thermal property parameters, including effective thermal conductivity, stagnant thermal conductivity, thermal mechanical dispersion coefficient, thermal dispersive degree, thermal diffusivity, heat capacity of aquifer, heat capacity and thermal conductivity of rock-soil skeletons, were accurately obtained. The test results are in good agreement with the empirical values. Meanwhile, the effective thermal conductivity of the aquifer also clearly increases with the increase of flow rate. The excitation temperature difference had little effect on the effective thermal conductivity of the aquifer. At the same time, numerical simulation methods are used to establish a numerical model consistent with the indoor test model, and the numerical model is assigned with the thermal property parameters obtained from the indoor slug heat test, and the measured values of temperature changes in the test well during the slug heat test under different hydrodynamic and excitation strength conditions are compared with the simulated values for verification. The research results show that the slug heat test has the characteristics of high applicability, simple operation and rapid testing, and can effectively determine the thermal properties parameters of aquifers and rock-soil skeletons.
      Citation: Water
      PubDate: 2022-09-26
      DOI: 10.3390/w14193020
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3021: Arsenic Concentration, Fraction, and
           Environmental Implication in Fe–Mn Nodules in the Karst Area of

    • Authors: Wenbing Ji, Rongrong Ying, Zhongfang Yang, Zhewei Hu, Qiong Yang, Xu Liu, Tao Yu, Lei Wang, Jianxun Qin, Tiansheng Wu
      First page: 3021
      Abstract: We determined the concentrations, geochemical fractions, and potential environmental implications of arsenic (As) via pH-static extraction experiments, X-ray photoelectron spectroscopy (XPS), and sequential extraction. Compared with the corresponding soils, the enrichment factors followed the order As (4.27) > Fe (2.14) > P (1.71) > Mn (1.41) > Al (0.95) > Ti (0.44) > Si (0.39) > Mg (0.28) > K (0.13). As showed a higher enrichment factor than all other elements. Arsenic showed a high linear correlation with iron in the FMNs, which can be expressed as As = 18.68Fe − 175.89 (r2 = 0.97, p < 0.01), indicating that Fe plays an important role in the geochemical behavior of As. Most of the As occurred as As (V) (83.79%) in the Fe–Mn nodules (FMNs), and As (III) (16.21%) only occupied a small portion. The distribution of As in the geochemical fractions of the FMNs followed the order F5 (99.54%) > F3 (0.25%) > F4 (0.10%) > F2 (0.09%) > F1 (0.02%), indicating that the residual fraction (F5) of As is the most dominant component. The total release of As from the nodules was extremely low (<0.01%) under neutral pH conditions (pH 6.0–8.0), and As was adsorbed and stabilized by the FMNs under neutral pH conditions (pH 6.0–8.0). However, overacidification or alkalization of the soil environment will promote As release, with subsequent ecological hazards.
      Citation: Water
      PubDate: 2022-09-26
      DOI: 10.3390/w14193021
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3022: Alteration of Dissimilatory Nitrate Reduction
           Pathways in the Intertidal Sediment during Macroalgae Blooms

    • Authors: Yukiko Senga, Tsubasa Sato, Kanae Shibaki, Megumi Kuroiwa, Seiichi Nohara, Yuichi Suwa
      First page: 3022
      Abstract: To elucidate the effect of macroalgae blooms on dissimilatory nitrate reduction pathways (denitrification, anammox, and DNRA) in sediments of the hypereutrophic Yatsu tidal flat, eastern Japan, sediment denitrification, anammox, and DNRA rates were measured using a 15N tracer technique at two sites affected and unaffected by macroalgae (Ulva) blooms and in incubation experiments with and without Ulva. Anammox was insignificant at both sites and in both experiments. The denitrification rate was consistently higher than the DNRA rate, and its contributions to the total dissimilatory nitrate reduction were 82% and 85% at sites affected and unaffected by Ulva, respectively. In a sediment incubation experiment with Ulva, the contribution of DNRA had increased to approximately 30% on day 7, which is when the sulfide concentration was the highest. Sulfide produced by sulfate reduction during macroalgae blooms inhibited denitrification and did not change the DNRA, and consequently increased the DNRA contribution. On day 21, after reaching the peak sulfide concentration during the late macroalgae collapse, the DNRA contribution decreased to 15%. These results indicated that the DNRA contribution was greater during the macroalgae blooms than at the collapse, although denitrification dominated DNRA regardless of the macroalgal status. Therefore, vigorous macroalgae cover and sulfide production under the macroalgae cover had an important impact on the nitrogen dynamics.
      Citation: Water
      PubDate: 2022-09-26
      DOI: 10.3390/w14193022
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3023: CSM-CERES-Wheat Sensitivity to
           Evapotranspiration Modeling Frameworks under a Range of Wind Speeds

    • Authors: Milad Nouri, Gerrit Hoogenboom, Mohammad Bannayan, Mehdi Homaee
      First page: 3023
      Abstract: Crop modeling uncertainty is expected to be high under weather data limitations; thus, jeopardizing decision-making on food-water security. Missing near-surface wind speed (u2) data required to accurately estimate reference evapotranspiration (ETo) seemed to significantly affect both the potential evapotranspiration (ETP) and yield simulations for data-scarce windy regions. In this study, the uncertainty in crop modeling based on different ETP approaches was assessed. In this regard, wheat yield and evapotranspiration were simulated with the CSM-CERES-Wheat model using either the Priestley-Taylor/Ritchie (PT) or the Penman-Monteith DSSAT (PM) methods under “rain-fed, low-nitrogen stress”, “rain-fed, high nitrogen stress”, “full irrigation, low nitrogen stress”, and “full irrigation, high nitrogen stress” scenarios for a u2 range from 0.8 to 3.5 m s−1. The daily weather data required to run the model were retrieved from 18 semi-arid areas located in western Iran. The statistically significant differences in mean yield and cumulative distribution were determined by the non-parametric Wilcoxon signed-rank and the Kolmogorov-Smirnov tests, respectively. The deviation in evaporation and transpiration simulated by applying PT and PM was lower under rain-fed condition. Under “rain-fed, low-nitrogen stress”, the PT-simulated yield deviated significantly (p < 0.05) from PM-simulated yield by more than 26% for the sites with u2 above 3 m s−1. The deviation in ETP estimates did not, however, lead to statistically significant difference in yield distribution curves for almost all sites and scenarios. Nitrogen deficiency resulted in a smaller difference in yield for rain-fed condition. The yield results showed a deviation below 6% under full irrigation condition. Under windy rain-fed condition, high deviation in leaf area index (LAI) and ETP estimates caused a large difference in the actual transpiration to potential transpiration ratio (Ta/TP), and yield. However, the deviation between PT- and PM-simulated LAI and Ta/TP for the full irrigation scenarios was less than 6%. Overall, the results from this study indicate that when soil moisture is depleted, resembling rain-fed condition, simulation of yield appears to be highly sensitive to the estimation of ETP for windy areas.
      Citation: Water
      PubDate: 2022-09-26
      DOI: 10.3390/w14193023
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3024: Drought Severity and Frequency Analysis Aided
           by Spectral and Meteorological Indices in the Kurdistan Region of Iraq

    • Authors: Heman Abdulkhaleq A. Gaznayee, Ayad M. Fadhil Al-Quraishi, Karrar Mahdi, Joseph P. Messina, Sara H. Zaki, Hawar Abdulrzaq S. Razvanchy, Kawa Hakzi, Lorenz Huebner, Snoor H. Ababakr, Michel Riksen, Coen Ritsema
      First page: 3024
      Abstract: In the past two decades, severe drought has been a recurrent problem in Iraq due in part to climate change. Additionally, the catastrophic drop in the discharge of the Tigris and Euphrates rivers and their tributaries has aggravated the drought situation in Iraq, which was formerly one of the most water-rich nations in the Middle East. The Kurdistan Region of Iraq (KRI) also has catastrophic drought conditions. This study analyzed a Landsat time-series dataset from 1998 to 2021 to determine the drought severity status in the KRI. The Modified Soil-Adjusted Vegetation Index (MSAVI2) and Normalized Difference Water Index (NDWI) were used as spectral-based drought indices to evaluate the severity of the drought and study the changes in vegetative cover, water bodies, and precipitation. The Standardized Precipitation Index (SPI) and the Spatial Coefficient of Variation (CV) were used as meteorologically based drought indices. According to this study, the study area had precipitation deficits and severe droughts in 2000, 2008, 2012, and 2021. The MSAVI2 results indicated that the vegetative cover decreased by 36.4%, 39.8%, and 46.3% in 2000, 2008, and 2012, respectively. The SPI’s results indicated that the KRI experienced droughts in 1999, 2000, 2008, 2009, 2012, and 2021, while the southeastern part of the KRI was most affected by drought in 2008. In 2012, the KRI’s western and southern parts were also considerably affected by drought. Furthermore, Lake Dukan (LD), which lost 63.9% of its surface area in 1999, experienced the most remarkable shrinkage among water bodies. Analysis of the geographic distribution of the CV of annual precipitation indicated that the northeastern parts, which get much more precipitation, had less spatial rainfall variability and more uniform distribution throughout the year than other areas. Moreover, the southwest parts exhibited a higher fluctuation in annual spatial variation. There was a statistically significant positive correlation between MSAVI2, SPI, NDWI, and agricultural yield-based vegetation cover. The results also revealed that low precipitation rates are always associated with declining crop yields and LD shrinkage. These findings may be concluded to provide policymakers in the KRI with a scientific foundation for agricultural preservation and drought mitigation.
      Citation: Water
      PubDate: 2022-09-26
      DOI: 10.3390/w14193024
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3025: Evaluation of a Slum Upgrading Program for
           Improvement of Water Supply in Bandung City, Indonesia

    • Authors: Dina Urfanisa, Shinobu Kazama, Satoshi Takizawa
      First page: 3025
      Abstract: A slum upgrading program has provided communal boreholes (KOTAKU boreholes) to improve water supply in slums of Indonesia. However, the achievement of the program was only estimated by the number of households served with the boreholes. We evaluated the water supply improvement by comparing actual water consumption, quality, and expenditure and household satisfaction of existing water sources in a slum of Bandung City, Indonesia. A high iron concentration and microbial contamination were observed in some KOTAKU boreholes, but the quality was better than that in the previous sources of the current KOTAKU borehole users. Twenty percent of the users spend more than 4% of their income on water due to bottled water and vended water for drinking and cooking. However, KOTAKU boreholes replaced that water for drinking and/or cooking, resulting in less water expenditure in low-income households. The average consumption was 134 L per capita per day (LPCD), which was higher than the target (60 LPCD) of the program. However, it was found that a highly intermittent water supply was the reason for household dissatisfaction rather than the amount of consumption. The program improved water supply; however, this study revealed the limitations of the water supply, namely, a lack of attention to continuous water supply and water quality.
      Citation: Water
      PubDate: 2022-09-26
      DOI: 10.3390/w14193025
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3026: How Complex Groundwater Flow Systems Respond
           to Climate Change Induced Recharge Reduction'

    • Authors: Timea Trásy-Havril, Szilvia Szkolnikovics-Simon, Judit Mádl-Szőnyi
      First page: 3026
      Abstract: Our recent knowledge about the role of different fluid driving forces in the response of groundwater flow systems to climate change is still limited. This current study aimed to evaluate possible spatial and temporal changes in complex, gravity- and overpressure-driven groundwater flow systems induced by climate change and look for general trends and characteristics of the flow field using 2D transient groundwater flow simulations. Results showed significant large-scale changes in the transient subsurface flow field and flow dynamics due to recharge reduction. Local gravity-driven flow systems are the most vulnerable to atmospheric processes, while overpressured regimes are expected to be independent of direct climatic variability. By the involvement of different degrees of overpressure, it was revealed that, as the degree of overpressure increases, the penetration depth of the topography-driven local flow systems decreases. The higher the overpressure, the lower the climate change-induced groundwater level decrease over time, suggesting the buffering effect of overpressure as a fluid driving force in the flow systems’ response to the changes in hydrologic parameters. The main novelty of the study is the involvement of different fluid driving forces in the evaluation with the combination of a regional scale investigation, which is unique in the context of climate change effects on groundwater systems.
      Citation: Water
      PubDate: 2022-09-26
      DOI: 10.3390/w14193026
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3027: ENSO Signals Recorded by Ash Tree Rings in
           Iberian Riparian Forests

    • Authors: Jesús Julio Camarero
      First page: 3027
      Abstract: Climate–atmospheric patterns affect ecological processes. The El Niño Southern Oscillation (ENSO) represents the strongest global source of climate variability at annual scales, but its impacts on Mediterranean forests are still understudied. Here, ENSO signals recorded by river flow and radial growth series of Mediterranean riparian forests are uncovered in the middle Ebro basin, northeastern Spain. A chronology or mean series of tree ring widths (period 1970–2018, 27 trees) was built for narrow-leaved ash (Fraxinus angustifolia). Growth indices increased as the river flow did during the prior winter and from May to September. Ash growth indices and river flow of the hydrological year were positively related (r = 0.54, p < 0.001), suggesting that a higher soil moisture enhances growth. This correlation remained significant after taking out the influence of precipitation. Ash growth indices (r = −0.46, p = 0.001) and river flow during the hydrological year (r = −0.30, p = 0.03) were negatively associated with the January Southern Oscillation Index (SOI). These relationships suggest that high SOI values corresponding to La Niña events lead to reduced river flow, thus decreasing ash radial growth. Further approaches could be used to better understand how the ENSO impacts drought-prone riparian forests subjected to increasing aridity.
      Citation: Water
      PubDate: 2022-09-26
      DOI: 10.3390/w14193027
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3028: Testing Groundwater Quality in Jouamaa Hakama
           Region (North of Morocco) Using Water Quality Indices (WQIs) and Fuzzy
           Logic Method: An Exploratory Study

    • Authors: El Mustapha Azzirgue, El Khalil Cherif, Taha Ait Tchakoucht, Hamza El Azhari, Farida Salmoun
      First page: 3028
      Abstract: Groundwater is one of the important determinants of human health in many regions of Morocco. Indeed, it is one of the government’s top concerns. However, slow and wrong decisions are hindering the advancement of the quality of groundwater in Morocco. The traditional monitoring methods are costly, time-consuming, and human-resource-intensive, especially in such a developing country. An exploratory study was conducted in the Jouamaa Hakama region in Morocco to test and compare groundwater quality using in situ measurements, water quality indices (WQIs), and a fuzzy logic (FL) method. The methodology followed in this study involves using and comparing four WQIs and FL based on in situ measurements at nine different wells along the Ouljat Echatt River downstream of the Chrafate wastewater treatment station. Twelve physical–chemical and bacteriological parameters: potential of hydrogen (pH), temperature (T°), turbidity (TURB), chemical oxygen demand (COD), biochemical oxygen demand in five days (BOD5), suspended matter (SM), phosphate (PO43-), nitrite (NO2−), nitrate (NO3−), ammonium (NH4+), dissolved oxygen (DO), electrical conductivity (EC), and fecal coliforms (FC) were measured in 2016 and 2017. The results show that all wells are of poor quality according to FL and WQIs; the Weighted Geometric WQI and Oregon WQI indicate that the groundwater is below the acceptable standard for human consumption, while the Weighted Arithmetic WQI and Logarithmic WQI indicate that the majority of wells are of good quality. These tested indices represent an excellent tool to support decision making and can be highly helpful in monitoring groundwater quality in vulnerable areas such as the Jouamaa Hakama region in the north of Morocco.
      Citation: Water
      PubDate: 2022-09-26
      DOI: 10.3390/w14193028
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3029: Discharge Estimation over Piano Key Weirs: A
           Review of Recent Developments

    • Authors: Raj Kumar Bhukya, Manish Pandey, Manousos Valyrakis, Panagiotis Michalis
      First page: 3029
      Abstract: The piano key (PK) weir has advanced over the labyrinth weir to increase the discharge capacity. Piano key weirs exhibit nonlinear flow behavior and are easy to place on the existing spillway or newly constructed dam with less base area. Various investigators are given equations to calculate the discharge coefficient for free and submerged flow conditions. The study focuses on reviewing the impacts of the PK weir geometry on the weir flow discharge coefficient, including weir length and height, upstream and downstream key widths, and apex overhangs. In this study, all possible aspects of PK weirs were briefly reviewed. From sensitivity analysis, it is observed that the discharge coefficient of the PK weir is more sensitive for the L/W dimensionless ratio followed by the B/P ratio. L is total length of the weir crest, W is width of the weir, B is total width of PK weir and P is height of the weir. This review paper is intended to serve as an accessible resource for hydraulic structures researchers and hydraulic engineering professionals alike interested in the hydraulics of PK weirs.
      Citation: Water
      PubDate: 2022-09-26
      DOI: 10.3390/w14193029
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3030: What Inspiring Elements from Natural Services
           of Water Quality Regulation Could Be Applied to Water Management'

    • Authors: Magali Gerino, Didier Orange, José Miguel Sánchez-Pérez, Evelyne Buffan-Dubau, Sophie Canovas, Bertrand Monfort, Claire Albasi, Sabine Sauvage
      First page: 3030
      Abstract: Theoretical and functional ecology is a source of useful knowledge for ecological engineering. The better understanding of the natural service of water quality regulation is now inspiring for optimization of water resource management, restoration and bioremediation practices. This transfer with a biomimicry approach applies particularly well in the urban, rural and agricultural areas, but is yet underexplored for water quality purposes. This natural service intensely involves the benthic boundary layer as a biogeochemical hot spot with living communities. A selection of processes related to the bioturbation phenomena is explored because of their influence on properties of the aquatic environment. The applications are valuable in a range of fields, from water treatment technology to management of ecosystems such as constructed and natural wetlands, streams, rivers, lagoons and coastal ecosystems. This paper gathers the more obvious cases of potential applications of bioturbation research findings on the biomimicry of natural services to water practices. These include pollution pumping by bioturbated sediment, water column oxygen saving during early diagenesis of deposits under conveyors transport and conservation of macroporous as well as fine sediment. Some applications for constructed devices are also emerging, including infiltration optimization and sewage reduction based on cross-biological community involvement.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193030
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3031: Investigation on the Impact of Different
           Absorber Materials in Solar Still Using CFD Simulation—Economic and
           Environmental Analysis

    • Authors: Chandrakant Sonawane, Ali Jawad Alrubaie, Hitesh Panchal, Ali J. Chamkha, Mustafa Musa Jaber, Ankit D. Oza, Sasan Zahmatkesh, Dumitru Doru Burduhos-Nergis, Diana Petronela Burduhos-Nergis
      First page: 3031
      Abstract: Solar stills are one of the low water production desalination systems, but its low yield makes it necessary to investigate different design and performance parameters to improve its productivity. This paper aims to perform a parametric analysis of a solar still desalination system and study the effect of different absorber materials on the performance of a single-slope solar desalination unit employing computational fluid dynamics (CFD) numerical simulation via COMSOL® Multiphysics software. To consider the absorptivity of water with different absorbing materials, simulation was conducted with the application of effective emissivity for the solar still walls. In addition, the economic, exergoeconomic, and CO2 mitigation of solar stills were studied. The results revealed that the hourly water output of the solar desalination unit, with different absorbing materials (black ink, black dye, and black toner), reached the maximum values at 1:00 PM. On comparing the simulation results of solar stills with and without absorbing materials, it has been observed that the solar still painted with black toner shows the highest improvement in hourly productivity, the exergy of evaporation, and evaporative heat transfer coefficient with a maximum increase in respective values by 10.52%, 13.68% and 5.37%. The CO2 mitigation and enviroeconomic parameter of the solar still using black toner were equal to 31.4 tons and 455.3 USD, respectively. Moreover, the lowest cost per liter (CPL) of the solar still was obtained using black toner, which was about 0.0066 USD/L.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193031
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3032: Calibration and Evaluation of Empirical
           Methods to Estimate Reference Crop Evapotranspiration in West Texas

    • Authors: Ripendra Awal, Atikur Rahman, Ali Fares, Hamideh Habibi
      First page: 3032
      Abstract: Evapotranspiration is an essential component of the hydrologic cycle, and its accurate quantification is crucial for managing crop water requirements and the operation of irrigation systems. Evapotranspiration data is key to hydrological and water management research investigations, including studying the impact of various climatic factors on crop water requirements. It has been estimated as the product of the reference crop evapotranspiration and crop coefficient. Daily reference crop evapotranspiration (ETo) can be determined by several methods and equations. The Food and Agriculture Organization Penman-Monteith equation requires complete weather data, whereas empirical equations such as Hargreaves and Samani, Valiantzas, Priestley-Taylor, Makkink, and Stephens-Stewart require limited weather data. This work evaluated different empirical equations for West Texas using the standard FAO Penman-Monteith method and calibrated their parameters to improve ETo estimation. Detailed meteorological data from West Texas Mesonet and high resolution (800 m) Parameter-elevation Regressions on Independent Slopes Model (PRISM) datasets from 2007 to 2016 were used. Daily ETo calculated using the standard FAO Penman-Monteith equation was compared to ETo estimated based on different empirical methods. The results show that all original empirical equations underestimated ETo. Calibration improved the performance of tested equations; however, there seems to be underestimation of ETo in the 8–16 mm range. Overall, the monthly Hargreaves and Samani equation with either original or calibrated values of its parameters outperformed all tested models. This equation seems to be a reasonable estimator, especially under limited weather data conditions.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193032
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3033: Evaluation of Grand Ethiopian Renaissance Dam
           Lake Using Remote Sensing Data and GIS

    • Authors: Asem Salama, Mohamed ElGabry, Gad El-Qady, Hesham Hussein Moussa
      First page: 3033
      Abstract: Ethiopia began constructing the Grand Ethiopian Renaissance Dam (GERD) in 2011 on the Blue Nile near the borders of Sudan for electricity production. The dam was constructed as a roller-compacted concrete (RCC) gravity-type dam, comprising two power stations, three spillways, and the Saddle Dam. The main dam is expected to be 145 m high and 1780 m long. After filling of the dam, the estimated volume of Nile water to be bounded is about 74 billion m3. The first filling of the dam reservoir started in July 2020. It is crucial to monitor the newly impounded lake and its size for the water security balance for the Nile countries. We used remote sensing techniques and a geographic information system to analyze different satellite images, including multi-looking Sentinel-2, Landsat-9, and Sentinel-1 (SAR), to monitor the changes in the volume of water from 21 July 2020 to 28 August 2022. The volume of Nile water during and after the first, second, and third filling was estimated for the Grand Ethiopian Renaissance Dam (GERD) Reservoir Lake and compared for future hazards and environmental impacts. The proposed monitoring and early warning system of the Nile Basin lakes is essential to act as a confidence-building measure and provide an opportunity for cooperation between the Nile Basin countries.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193033
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3034: An Eco-Study for a Feasible Project:
           “Torun and Its Vistula Stretch—An Important Green Navigation
           Spot on a Blue Inland Waterway”

    • Authors: Valentina-Mariana Manoiu, Alexandru-Ioan Craciun, Katarzyna Kubiak-Wójcicka, Marina Antonescu, Bogdan Olariu
      First page: 3034
      Abstract: This paper aims to present the main trends of an eco-study for a possibly challenging future inland waterway transportation project. The study will prove if Torun and its Vistula stretch represent a viable and profitable spot on this inland waterway, and its outcomes will constitute a sound baseline that can be used for the project itself but also for many scientific, educational and economic purposes. The eco-multilayer research will comprise the following elements: hydrology and biology of the Torunian Vistula (TV) stretch, and water quality; a public opinion survey; the urban functions of the TV segment (social, educational, urban planning, aesthetical, recreational, cultural, utilitarian and economical). The conclusion is that the eco-research and the project will improve Torun City’s image as a Green Urban Space, in terms of respect towards the environment, a sustainable form of transport, and attractive ways of relaxation and spending leisure time by Torun’s population and visitors. The eco-study and the project will contribute to promoting the Torun region by supporting the possibility of watching beautiful landscapes (sightseeing tours) spread along the Vistula River. The project itself will have a positive impact on the Torunian economy and on the lifestyle of Torun’s citizens.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193034
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3035: Parameters Tuning of Fractional-Order
           Proportional Integral Derivative in Water Turbine Governing System Using
           an Effective SDO with Enhanced Fitness-Distance Balance and Adaptive Local

    • Authors: Weiguo Zhao, Hongfei Zhang, Zhenxing Zhang, Kaidi Zhang, Liying Wang
      First page: 3035
      Abstract: Supply-demand-based optimization (SDO) is a swarm-based optimizer. However, it suffers from several drawbacks, such as lack of solution diversity and low convergence accuracy and search efficiency. To overcome them, an effective supply-demand-based optimization (ESDO) is proposed in this study. First, an enhanced fitness-distance balance (EFDB) and the Levy flight are introduced into the original version to avoid premature convergence and improve solution diversity; second, a mutation mechanism is integrated into the algorithm to improve search efficiency; finally, an adaptive local search strategy (ALS) is incorporated into the algorithm to enhance the convergence accuracy. The effect of the proposed method is verified based on the comparison of ESDO with several well-regarded algorithms using 23 benchmark functions. In addition, the ESDO algorithm is applied to tune the parameters of the fractional-order proportional integral derivative (FOPID) controller of the water turbine governor system. The comparative results reveal that ESDO is competitive and superior for solving real-world problems.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193035
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3036: Development Trends and Research Frontiers of
           Preferential Flow in Soil Based on CiteSpace

    • Authors: Chao Liu, Ying Yuan, Aihong Zhou, Lefan Guo, Hongrui Zhang, Xuedi Liu
      First page: 3036
      Abstract: Preferential flow is a non-equilibrium flow in unsaturated soil through which water infiltrates deep into the ground quickly. It has been studied in many fields, such as environment, agriculture, and hydrology. However, researchers from different disciplines have a different understanding of preferential flow, and it is difficult to grasp its development trends and research frontiers through qualitative analysis in a single field, while they can be quantitatively and objectively analyzed through bibliometrics with scientific knowledge map tools. This paper collects 3315 research studies on preferential flow in soil from the Web of Science (WoS) core collection database within 30 years, conducts a statistical analysis on keywords, countries, and research institutions of these studies based on CiteSpace, draws visualized scientific knowledge maps, and presents the development trends and research frontiers of preferential flow. Results showed that preferential flow is a multi-scale coexistence phenomenon, and researchers from different disciplines study preferential water flow movement and pollution at different research scales. New techniques and ideas are research hotspots and directions. Moreover, the difference between bibliometrics methods and review methods is analyzed. This paper is presented to provide a referable knowledge structure and new ideas for research in related fields and to help promote cross-integration between disciplines.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193036
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3037: Quickly Assess the Direct Loss of Houses
           Caused by a Typhoon-Rainstorm-Storm Surge–Flood Chain: Case of
           Haikou City

    • Authors: Jinhong Wan, Lisha Wang, Yaojie Yue, Zhiyuan Wang
      First page: 3037
      Abstract: With changing climate, coastal areas are facing increasingly threats from the typhoon–rainstorm–storm surge-flood (TRSSF) chain. However, among various exposures of the TRSSF chain, it is still a great challenge to quickly assess the direct losses of houses, due to the complex mechanisms underlying building damage. The objective of this article is therefore to explore a simple method of quickly assessing the house losses caused by the TRSSF chain, based on a small amount of data. To achieve this goal, a method of multi factors regression and a spatial information network were proposed. The results in Haikou City show that the loss rate of house assets is significantly lower than that of indoor property. Spatially, the areas with higher loss rates are generally distributed along the Nandu River. The direct economic losses associated with houses in the return periods of 10, 20, 50, and 100 years range from 1.3 to 2 billion RMB. Our findings highlight the significance and possibility of quickly assessing the direct house losses caused by TRSSF chain using a small amount of data. It indicates that the house losses are not only determined by TRSSF intensity, but also closely related to socio-economic, topography and house location.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193037
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3038: Response of the Headcut Erosion Process to
           Flow Energy Variation in the Loess Gully Region of China

    • Authors: Qianhua Shi, Wenlong Wang, Lanqian Feng
      First page: 3038
      Abstract: In the headcut erosion process, flow energy is transformed and consumed when runoff is used to transport sediment. Therefore, flow energy variations are critical in the study of headcut erosion. The aim of this study was to illustrate the effects of the upslope inflow discharge and slope gradient on flow energy and the response of the sediment yield of headcut erosion to flow energy variations in China’s Loess Plateau. This study examined the headcut erosion using slope gradients ranging from 1° to 7° and designed and upslope inflow discharges of 3.6, 4.8, 6.0 and 7.2 m3·h−1. The rainfall intensity was set as invariable 0.8 mm·min−1. The results showed that the kinetic energy at the downstream gully bed was 0.03~0.16 J·s−1 lower than that in the upstream catchment area because of the concentrated flow drop at the gully head. The potential energy at the summit and bottom of the plot were both affected by upstream inflow discharge and slope gradient. The flow energy consumption values of the gully head increased by approximately 1.26 times as the inflow discharge increased by 1.2 m3·h−1. Greater energy consumption occurred at the gully head than in the upstream catchment area and downstream gully bed, and the gully head contribution to the flow energy consumption was 44.30~64.29%, which showed an increasing trend as the upslope inflow discharge increased and slope gradient decreased. The influence of the slope gradient on the sediment yield was stronger than that of the upslope inflow discharge, and a nonlinear regression equation was established to calculate the sediment yield. The flow energy consumption showed a significant correlation with the sediment yield (p < 0.01). Our results could enhance the understanding of the flow energy variations and headcut evolution process during headcut erosion and can also be helpful in the design of gully erosion prevention measures.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193038
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3039: Analysis of Water Supply Capacity of a Sand

    • Authors: Il-Moon Chung, Jeongwoo Lee, Min Gyu Kim, Il-Hwan Kim, Bisrat Ayalew Yifru
      First page: 3039
      Abstract: A sand dam is an old technology used to trap sand materials and store water in dry riverbeds. Besides the volume of sand stored, the water storage and supply capacity of the sand dam depends principally on material properties including hydraulic conductivity (K) and the specific yield (Sy). In this study, the water supply capacity of a sand dam, applied in South Korea with a modified scheme, was analyzed. Imported sand materials were placed in three layers, and perforated drain pipes were installed to abstract the water to a collection tank. Using a Modular Finite-Difference Groundwater Flow (MODFLOW) model, the drain pipe discharge related to aquifer properties and supply capacity of a sand dam was evaluated. Using the model, the productivity of the sand storage with several cases of inflow conditions was assessed. For the period from 9 March 2020 to 16 May 2022, the results of calculation of water supply for the installation and operation of new sand dam are as follows. Regarding the actual inflow condition, compared to the average water supply of the existing water intake source, the sand dam installation increased water supply by 61.6%, and the sand dam installation showed an effect of improving the water supply by 36.0% for the minimum water supply. The calculated water supply for the condition where the inflow was reduced by 50% showed an effect of improving water supply by over 70% on average due to the installation of the sand dam. The findings would be a benchmark for future expansions of the scheme in related places, and management and maintenance of the system.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193039
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3040: Pollution Evaluation of the El Pueblito River
           in Queretaro, Mexico, Using the Water Quality Index

    • Authors: Enrique Rodriguez-Nuñez, Christian Hernandez-Mendoza, Victor Perez-Moreno, Arely Cardenas
      First page: 3040
      Abstract: This study evaluated the water pollution of the El Pueblito River by employing physicochemical parameters and biological indicators. Monitoring was conducted weekly during three months at seven sampling sites. To ease the representation of the results of this analysis, the water quality index (WQI) was calculated. The results obtained by the physicochemical analysis show the same trends as those of the analyses performed with bioassays using Daphnia magna and the WQI. The obtained values showed a deterioration of water quality from upstream to downstream due to the discharges into the river that occurred as it went through the city of Corregidora. The WQI values shifted from good water quality (83.00 ± 7.40) upstream to poor water quality (27.00 ± 0.85) downstream. This study also shows the utility of the WQI and how a Daphnia magna toxicity test can be an affordable and fast tool used to indicate high levels of pollution, such as in the case of El Pueblito River.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193040
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3041: Two-Step Simulation of Underwater Terrain in
           River Channel

    • Authors: Yan Liang, Bo Wang, Yehua Sheng, Changqing Liu
      First page: 3041
      Abstract: When studying river hydrodynamics and water quality evolution laws on the basis of numerical simulation analysis, it is necessary to carry out topographic interpolation along the bend direction of the river on the basis of the measured river section, as this can provide accurate and reliable topographic data for river numerical modeling. In this paper, a two-step terrain simulation method based on sparse and discrete river sections is proposed by comprehensively considering the river trends and the lack of monitoring sections. On the basis of establishing a reference using the river centerline and coding the spatial relationship of the river, the linear weight method, which uses the distance and gradient change between the known sampling elevation section to realize the preliminary encryption of spatial points with any number of longitudinal sections and any horizontal distance, is carried out first. Considering the structural and anisotropic characteristics of the river, the improved inverse distance weighting (IDW) method is further used to locally interpolate the encrypted points to obtain the continuous surface of the river terrain. In order to prove the effectiveness of this method, a part of the Qinhuai River in Nanjing was taken as the research object. The experiment was carried out by setting different spacing distances for preliminary densification and by using different interpolation methods for further local terrain simulation. Root mean square error (RMSE) and mean absolute error (MAE) are used to evaluate the overall performance of different simulation methods. The experimental results show that the method proposed in this paper overcomes the obvious inaccuracy of directly using an interpolation algorithm to generate the river terrain due to sparse section data. The river terrain generated by the preliminary densification and improved IDW interpolation calculation method is more reasonable, and continuous and unobstructed, reflecting the original river terrain more accurately.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193041
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3042: Experimental and Theoretical Explanations for
           the Initial Difference in the Hydraulic Head in Aquitards

    • Authors: Yongliang Xu, Chaoyang Du, Haizhi Ma, Wei Pang, Suhang Huang, Shimin Li
      First page: 3042
      Abstract: Accurate estimation of the buoyancy forces exerted on underground structures is a problem in geotechnical engineering that directly impacts the construction safety and cost of these structures. Therefore, studying the buoyancy resistance of underground structures has great scientific and practical value. In this study, an initial difference in the hydraulic head, Δh0, was discovered to be present in aquitards through analysis of water-level data collected from the observation of real-world structures and in laboratory control tests. That is, seepage occurs beyond a threshold Δh0. Analysis of test data reveals that a deviation from Darcy’s law is the theoretical basis for Δh0 and that Δh0 equals the initial hydraulic gradient multiplied by the length of the seepage path. The general consistency between the experimentally measured and theoretically calculated values of Δh0 validates the theoretical explanation for Δh0. The results of this study provide a basis for scientifically calculating the buoyancy resistance required for the construction of underground structures.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193042
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3043: Local Governance of Groundwater Resources
           through the Lens of Stakeholders in the Context of State-Led Management in
           the Lower Mekong Region

    • Authors: Preeyaporn Muenratch, Thi Phuoc Lai Nguyen
      First page: 3043
      Abstract: Local groundwater governance in the Lower Mekong Region (LMR) is often inadequate and ineffective because of policy incoherence and lack of public participation; thus, groundwater exploitation and pollution have been accelerated in many LMR countries. Through a case study in Khon Kaen, Thailand, this study aims to assess the state of local groundwater governance (GWG) through the stakeholders’ perception by using Water Governance Framework developed by the Organization for Economic Co-operation and Development (OECD). Although it is useful for the assessment at the national scale, it is still inadequate and has some limitations on the local scale. Hence, the principles were reconsidered and translated to fit the local context. Descriptive statistical analysis was used to explain the state of GWG, while confirmatory factor analysis (CFA) was used to examine the relations between GWG indicators and GWG dimensions. The findings show that clear roles and responsibilities are have the highest performance. However, integrity and transparency are the challenges of GWG. We found that the indicators explained the effectiveness, efficiency, and trust and engagement in the GWG model. Consequently, this study contributes stakeholder involvement in GWG assessment. The findings show to policymakers and policy practitioners the current state of GWG and propose key indicators in groundwater governance assessment at the local context.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193043
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3044: Variability of Carbon Export in the Lower
           Mississippi River during an Extreme Cold and Warm Year

    • Authors: Lee Potter, Y. Jun Xu
      First page: 3044
      Abstract: The Mississippi River (MR) discharges on average 474 km3 of water annually into the Northern Gulf of Mexico (NGOM) with a large quantity of carbon, playing a vital role in the ecosystem’s food chain and water quality. In this study, we analyzed exports of dissolved inorganic (DIC) and organic carbon (DOC) from January 2021 to December 2021, during which the contiguous United States experienced one of the coldest winters as well as the hottest summer on record. Bi-weekly in situ river measurements and water sampling were conducted in the lower MR at Baton Rouge in Louisiana, USA, approximately 368 km from the river’s mouth. We found that the MR transported 12.61 Tg C of DIC and 4.54 Tg C of DOC into the NGOM during the study period. Much of the DOC mass export occurred during the winter (~38%), while much of the DIC mass export took place in the spring months (~35%). The seasonality of DOC and DIC exports was affected by their concentrations, water temperature, and discharge. DIC concentrations were significantly higher in the fall (32.0 mg L−1) than those during the winter (20.4 mg L−1), while DOC concentrations were highest during the winter months (11.3 mg L−1) and varied seasonally, however, not significantly. Partial pressure of dissolved carbon dioxide (pCO2) in the MR averaged 1703 ± 646 µatm peaking in the summer at 2594 µatm and reaching a low in the winter at 836 µatm. Outgassing of CO2 (FCO2) peaked in the spring averaging 3.43 g C m2 d−1 and was lowest in the winter at 1.62 g C m2 y−1. Our findings validate our initial hypotheses that seasonal variability and weather extremes strongly affect terrestrial-aquatic carbon transfer, and that climate change will likely intensify carbon export from the Mississippi River Basin.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193044
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3045: Dynamic Formation Processes and
           Characteristics of “28 June 2012” Debris Flow in Aizi Valley,
           Ningnan County, Sichuan Province, China

    • Authors: Na He, Daxiang Liu, Xianggang Zhang, Linjuan Xu, Zhiquan Yang
      First page: 3045
      Abstract: On 28 June 2012, a large debris flow occurred in Aizi gully, Ningnan County, Sichuan Province, China. It was the most significant debris flow disaster at a construction site in 2012 in China, which left 40 people dead or missing. Field investigations and model calculations were conducted following the event in order to determine dynamic parameters and execute engineering mitigation measures. Analyzing the collected data, it is found that earthquake and drought play a dominant role in debris flow initiation, and from 1 January 1986 to 31 December 2010, 43 earthquakes with a magnitude greater than 3.0 occurred around the study area. Through calculation it was found that the inducive radius of 16 earthquakes was larger than the distance between the epicenter and the study area, and it proves that the study area is frequently affected by seismic activities. Furthermore, on the basis of calculation of rainfall anomaly index H from January 2011 to June 2012, it can be seen that the rainfall of 2011 is extremely low. The percentage of the rainfall anomaly index is almost less than −34%, which indicates that the drought in the basin is serious. Under the influences of repeated seismic activities and continuous droughts, the structure of soil was destroyed and its strength and permeability changed significantly, providing favorable conditions for debris flow initiation. On 28 June 2012, heavy rainfall with the intensity of 23.3 mm/h occurred, and the total amount of precipitation reached 66.1 mm before 6am of 28 June 2012. Debris flow was induced due to the triggering effect of the torrential rain. Studying the causes of the large-scale debris flows in construction sites can significantly facilitate the prevention and mitigation of future debris flow disasters, as well as reduce the potential of hazards caused by debris flows in major engineering areas.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193045
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3046: Sentinel-1 and Sentinel-2 Data to Detect
           Irrigation Events: Riaza Irrigation District (Spain) Case Study

    • Authors: Anna Balenzano, Giuseppe Satalino, Francesco Paolo Lovergine, Annarita D’Addabbo, Davide Palmisano, Riccardo Grassi, Ozlem Ozalp, Francesco Mattia, David Nafría García, Vanessa Paredes Gómez
      First page: 3046
      Abstract: This paper investigates the use of high resolution (~100 m) surface soil moisture (SSM) maps to detect irrigation occurrences, in time and space. The SSM maps have been derived from time series of Copernicus Sentinel-1 (S-1) and Sentinel-2 (S-2) observations. The analysis focused on the Riaza irrigation district in the Castilla y León region (Spain), where detailed information on land use, irrigation scheduling, water withdrawal, meteorology and parcel borders is available from 2017 to 2021. The well-documented data basis has supported a solid characterization of the sources of uncertainties affecting the use of SSM to map and monitor irrigation events. The main factors affecting the irrigation detection are meteo-climatic condition, crop type, water supply and spatial and temporal resolution of Earth observation data. Results indicate that approximately three-quarters of the fields irrigated within three days of the S-1 acquisition can be detected. The specific contribution of SSM to irrigation monitoring consists of (i) an early detection, well before vegetation indexes can even detect the presence of a crop, and (ii) the identification of the irrigation event in time, which remains unfeasible for vegetation indexes. Therefore, SSM can integrate vegetation indexes to resolve the irrigation occurrences in time and space.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193046
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3047: Communal Wastewater Treatment Plants’
           Effectiveness, Management, and Quality of Groundwater: A Case Study in

    • Authors: Widodo Brontowiyono, Thomas Boving, Adelia Anju Asmara, Suphia Rahmawati, Andik Yulianto, Noviani Ima Wantoputri, Annisa Nur Lathifah, Yuli Andriansyah
      First page: 3047
      Abstract: The Special Region of Yogyakarta is one of the provinces in Indonesia with a large number of communal wastewater treatment plants (CWWTPs). However, less than 40% of CWWTPS in the province are able to be operated well. This study aims to determine the effectiveness of CWWTPs concerning the quality of the surrounding groundwater. The research location was in Mlati, one of three sub-districts with the highest number of CWWTPs and highest population density in the province. Technical data were analyzed in a laboratory, including water quality of CWWTPs and groundwater quality. This study also analyzed non-technical data related to CWWTP management. These data were collected through in-depth interviews with CWWTP managers and users. The data were analyzed systematically, not only quantitatively but qualitatively. The distribution of water quality from CWWTP treatment and groundwater was mapped using inverse distance weighting (IDW). The results show that the CWWTP effluent meets quality standards for pH, temperature, COD, oil and grease, and ammonia. However, some CWWTPs fail to meet the quality standards for the TSS and E. coli parameters. Groundwater has an acidic pH, with ammonia, nitrite, and zinc parameters meeting quality standards, but oil and grease, COD, nitrate, and Pb concentrations exceed quality standards in several wells. This study indicates that the presence of CWWTPs is not correlated with the quality of groundwater due to the inefficiency of the CWWTPs, the unmet coverage area, and the conditions of sanitation facilities at the location.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193047
      Issue No: Vol. 14, No. 19 (2022)
  • Water, Vol. 14, Pages 3048: Preparation of Powdered Activated Carbon
           Composite Material and Its Adsorption Performance and Mechanisms for
           Removing RhB

    • Authors: Yarui Song, Kaisheng Wang, Fajun Zhao, Zhaoxi Du, Biao Zhong, Guangyu An
      First page: 3048
      Abstract: For solving the problem of low efficiency about dyes and slow precipitation rate for powdered activated carbon (PAC), this study successfully prepares a kind of powdered activated carbon-based composites (PACMC) to remove Rhodamine B (RhB) in wastewater as an adsorbent. PACMC derived from potassium humate and polyaluminium chloride (PACl)-modified PAC were fabricated via a chemical precipitation method. We confirmed the micro-morphology and chemical composition of PACMC by scanning electron microscopy energy-dispersive X-ray spectrometer (SEM-EDS) and fourier infrared spectroscopy (FT-IR), certifying that PACMC was synthesized by chemical reaction of raw materials. PACMC has layered porous structure and functional groups, which is beneficial to the transport and diffusion of RhB molecules. The specific surface area (10.098 m2·g−1) and average particle size (142.9 µm) of PACMC and the specific surface area (710.1 m2·g−1) and average particle size (11.9 µm) of PAC were measured. By comparison, it can be seen that PACMC has larger average particle size conducive to solid–liquid separation. The static adsorption experiments were carried out to investigate the adsorption properties of RhB by PACMC. The results showed that the adsorption capacity of PACMC for RhB was 2–3 times as high as that of PAC. The pH value of the solution had a significant effect on the adsorption of RhB by PACMC and the maximum adsorption was observed at pH = 4.5 (qe = 28.56 mg·g−1, C0 = 40 mg·L−1). The adsorption of RhB by PACMC can be well described by the pseudo-second-order kinetics. The kinetic results revealed that the adsorption process involved several steps, where the chemical adsorption and intra-particle diffusion both played the important roles. The isothermal adsorption data were in accordance with the Dubinin–Radushkevich model, which indicated that the adsorption was dominated by the chemisorption mechanism. Therefore, the adsorption mechanisms included chemical binding/chelation effect and electrostatic adsorption effect.
      Citation: Water
      PubDate: 2022-09-27
      DOI: 10.3390/w14193048
      Issue No: Vol. 14, No. 19 (2022)
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
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