Subjects -> MATHEMATICS (Total: 1013 journals)
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    - MATHEMATICS (714 journals)
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APPLIED MATHEMATICS (92 journals)

Showing 1 - 82 of 82 Journals sorted alphabetically
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 12)
Advances in Applied Mathematics and Mechanics     Full-text available via subscription   (Followers: 7)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 15)
AKCE International Journal of Graphs and Combinatorics     Open Access  
American Journal of Applied Mathematics and Statistics     Open Access   (Followers: 10)
American Journal of Applied Sciences     Open Access   (Followers: 22)
American Journal of Modeling and Optimization     Open Access   (Followers: 2)
Annals of Actuarial Science     Full-text available via subscription   (Followers: 2)
Applied Mathematical Modelling     Full-text available via subscription   (Followers: 23)
Applied Mathematics and Computation     Hybrid Journal   (Followers: 31)
Applied Mathematics and Mechanics     Hybrid Journal   (Followers: 4)
Applied Mathematics and Nonlinear Sciences     Open Access   (Followers: 1)
Applied Mathematics and Physics     Open Access   (Followers: 3)
Biometrical Letters     Open Access  
British Actuarial Journal     Full-text available via subscription   (Followers: 2)
Bulletin of Mathematical Sciences and Applications     Open Access  
Communication in Biomathematical Sciences     Open Access   (Followers: 2)
Communications in Applied and Industrial Mathematics     Open Access   (Followers: 1)
Communications on Applied Mathematics and Computation     Hybrid Journal   (Followers: 1)
Differential Geometry and its Applications     Full-text available via subscription   (Followers: 4)
Discrete and Continuous Models and Applied Computational Science     Open Access  
Discrete Applied Mathematics     Hybrid Journal   (Followers: 10)
Doğuş Üniversitesi Dergisi     Open Access  
e-Journal of Analysis and Applied Mathematics     Open Access  
Engineering Mathematics Letters     Open Access   (Followers: 1)
European Actuarial Journal     Hybrid Journal  
Foundations and Trends® in Optimization     Full-text available via subscription   (Followers: 2)
Frontiers in Applied Mathematics and Statistics     Open Access   (Followers: 1)
Fundamental Journal of Mathematics and Applications     Open Access  
International Journal of Advances in Applied Mathematics and Modeling     Open Access   (Followers: 1)
International Journal of Applied Mathematics and Statistics     Full-text available via subscription   (Followers: 3)
International Journal of Computer Mathematics : Computer Systems Theory     Hybrid Journal  
International Journal of Data Mining, Modelling and Management     Hybrid Journal   (Followers: 10)
International Journal of Engineering Mathematics     Open Access   (Followers: 4)
International Journal of Fuzzy Systems     Hybrid Journal  
International Journal of Swarm Intelligence     Hybrid Journal   (Followers: 2)
International Journal of Theoretical and Mathematical Physics     Open Access   (Followers: 13)
International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems     Hybrid Journal   (Followers: 3)
Journal of Advanced Mathematics and Applications     Full-text available via subscription   (Followers: 1)
Journal of Advances in Mathematics and Computer Science     Open Access  
Journal of Applied & Computational Mathematics     Open Access  
Journal of Applied Intelligent System     Open Access  
Journal of Applied Mathematics & Bioinformatics     Open Access   (Followers: 6)
Journal of Applied Mathematics and Physics     Open Access   (Followers: 9)
Journal of Computational Geometry     Open Access   (Followers: 3)
Journal of Innovative Applied Mathematics and Computational Sciences     Open Access   (Followers: 11)
Journal of Mathematical Sciences and Applications     Open Access   (Followers: 2)
Journal of Mathematics and Music: Mathematical and Computational Approaches to Music Theory, Analysis, Composition and Performance     Hybrid Journal   (Followers: 12)
Journal of Mathematics and Statistics Studies     Open Access  
Journal of Physical Mathematics     Open Access   (Followers: 2)
Journal of Symbolic Logic     Hybrid Journal   (Followers: 2)
Letters in Biomathematics     Open Access   (Followers: 1)
Mathematical and Computational Applications     Open Access   (Followers: 3)
Mathematical Models and Computer Simulations     Hybrid Journal   (Followers: 3)
Mathematics and Computers in Simulation     Hybrid Journal   (Followers: 3)
Modeling Earth Systems and Environment     Hybrid Journal   (Followers: 1)
Moscow University Computational Mathematics and Cybernetics     Hybrid Journal  
Multiscale Modeling and Simulation     Hybrid Journal   (Followers: 2)
Pacific Journal of Mathematics for Industry     Open Access  
Partial Differential Equations in Applied Mathematics     Open Access   (Followers: 2)
Ratio Mathematica     Open Access  
Results in Applied Mathematics     Open Access   (Followers: 1)
Scandinavian Actuarial Journal     Hybrid Journal   (Followers: 2)
SIAM Journal on Applied Dynamical Systems     Hybrid Journal   (Followers: 3)
SIAM Journal on Applied Mathematics     Hybrid Journal   (Followers: 11)
SIAM Journal on Computing     Hybrid Journal   (Followers: 11)
SIAM Journal on Control and Optimization     Hybrid Journal   (Followers: 18)
SIAM Journal on Discrete Mathematics     Hybrid Journal   (Followers: 8)
SIAM Journal on Financial Mathematics     Hybrid Journal   (Followers: 3)
SIAM Journal on Imaging Sciences     Hybrid Journal   (Followers: 7)
SIAM Journal on Mathematical Analysis     Hybrid Journal   (Followers: 4)
SIAM Journal on Matrix Analysis and Applications     Hybrid Journal   (Followers: 3)
SIAM Journal on Numerical Analysis     Hybrid Journal   (Followers: 7)
SIAM Journal on Optimization     Hybrid Journal   (Followers: 12)
SIAM Journal on Scientific Computing     Hybrid Journal   (Followers: 16)
SIAM Review     Hybrid Journal   (Followers: 9)
SIAM/ASA Journal on Uncertainty Quantification     Hybrid Journal   (Followers: 2)
Swarm Intelligence     Hybrid Journal   (Followers: 3)
Theory of Probability and its Applications     Hybrid Journal   (Followers: 2)
Uniform Distribution Theory     Open Access  
Universal Journal of Applied Mathematics     Open Access   (Followers: 1)
Universal Journal of Computational Mathematics     Open Access   (Followers: 3)
Similar Journals
Journal Cover
Modeling Earth Systems and Environment
Number of Followers: 1  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 2363-6203 - ISSN (Online) 2363-6211
Published by Springer-Verlag Homepage  [2469 journals]
  • Mathematical modelling and analysis to study the impact of mining on
           natural interactive dynamics between plants and carbon dioxide

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      Abstract: Abstract A mathematical model is formulated to delve into the changes that have been produced on the natural interactive dynamics between plants and carbon dioxide when mining intervenes between them. The model is represented as a nonlinear system of ordinary differential equations comprising dynamic interactions among plants, carbon-dioxide, and mining. In the model formulation, it is assumed that mining activities enhance carbon dioxide in the atmosphere and cause plants’ ruination. The qualitative analysis of the model is executed to obtain properties like boundedness, identification of equilibrium solutions, and their stabilities. Besides qualitative investigation, the formulated model is also quantitatively analyzed from the obtained numerical solutions. The numerical values of input model parameters are estimated from global observational data of plants and carbon dioxide. However, the influential parameters towards the model outcomes are identified through a global sensitivity analysis technique that combines the evaluation of Partial Rank Correlation Coefficients (PRCCs) with Latin Hypercube Sampling (LHS). To better elucidate the role of mining over the interactive dynamics, results obtained from the proposed model are compared with the model that does not involve mining activities as one of the dynamic variables. The overall mathematical analyses reveal that the equilibrium level of carbon-dioxide concentration exhibits a significant increase, and stability of the system gets harder to achieve in the presence of mining. It is also being deduced that system outcomes are more sensitive towards mining-related parameters than plant density and carbon dioxide concentration parameters.
      PubDate: 2022-08-12
       
  • Geospatial simulation and mapping of climate suitability for oil palm
           (Elaeis guineensis) production in Peninsular Malaysia using GIS/remote
           sensing techniques and analytic hierarchy process

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      Abstract: Abstract Malaysia is estimated to have cultivated over 5 million hectares of oil palm (Elaeis guineensis), making it the most dominant plantation crop in the country. Malaysia produces about 45% of the world's total palm oil, and it exports about 80% of it. This study aims to identify suitable area for oil palm production in Peninsular Malaysia using remote sensing and GIS techniques and Analytic Hierarchy Process (AHP). Modeling the climate suitability of oil palm production in Peninsular Malaysia using the AHP model of Multi-Criteria Evaluation (MCE) revealed that an annual rainfall rate of approximately (33) was the most important factor contributing to climate suitability. Other contributing factors to climate suitability include number of dry months (17%), annual mean temperature (11%), annual maximum temperature (8%), temperature of the coldest month (7%), slope (5%), elevation (5%), mean annual water deficit (4%), soil texture (4%), soil depth (3%) and coarse fragment (3%) is the least contributing factor. The findings of the study revealed that the current climate in Peninsular Malaysia are suitable for oil palm production. A highly suitable climate is found around Selangor, Kelantan, Perak and Kedah. Climates that are unsuitable are predicted to increase by 5.6% by 2040 and by 5.72% by 2080 from 1.77% in 2020. Climate conditions will become unsuitable for oil palm production along the coast of Pahang and Selangor, and Perlis by 2080. The study recommends the use of the improved variety, appropriate selection of planting area, irrigation where necessary, enhance institutional research on climate and oil palm, communication and availability of academic findings, and the use of technology transfer.
      PubDate: 2022-08-11
       
  • Analysis of carbon mono oxide concentrations in heterogeneous traffic
           conditions: a case study of Kanpur city in India

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      Abstract: Abstract Air pollution in urban city areas is a cause of concern among the city dwellers. Air pollution not only deteriorates the health of the living beings, it also causes environmental and climatic problems. One of the major components of air pollution is carbon monoxide. In urban city areas vehicular traffic is the major source of carbon monoxide. There exists a problem in the society if the carbon monoxide is not managed properly. Therefore, this proposed research is a case study conducted in a heterogeneous traffic area to understand the concentration of carbon monoxide so that it can be managed with low concentrations. This case study was conducted in Kanpur city in India. CALINE4 software was used for modelling and the output from the standard run type model shows that the predicted Carbon monooxide concentration is mainly dependent on wind speed and wind direction. The co efficient of determination values of 0.8252 suggests that the model explained 82.52% of the original variability in the data during free flow traffic condition, while co efficient of determination value of 0.2380 suggests that the model explained 23.80% of the original variability in the data during congested condition on road. To validate the statistical significance of the model performance during different traffic flow condition, statistical analysis using model bias normalized mean square error and fractional bias is also conducted.
      PubDate: 2022-08-09
       
  • Numerical analysis of the influence of approach flow conditions on the
           efficiency of labyrinth weir

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      Abstract: Abstract The majority of published studies on labyrinth weir are limited to the influence of geometric parameters on its efficiency. However, approach flow conditions can have a significant impact on the discharge capacity of such type of weir. This study utilized numerical modeling to investigate and analyze the effects of the channel bed level on the behavior of a rectangular labyrinth weir designed with a rounded entrance. Validation of the numerical model was carried out by comparing the computed results with the experimental data previously obtained. The relative Mean Absolute Relative Error between the physical and numerical results for different discharges coefficient varies between 1.7 and 7%. These show that the numerical model is capable of correctly representing the experimental results and flow behavior over the labyrinth weir. Then, three arrangements of channel bed levels were designed and simulated: lowering both the upstream and the downstream; lowering only the upstream; and, lowering only the downstream. These simulations enable to analyze the influence of the approach flow conditions by providing more information about flow characteristics, including water surface profile and velocity field. It is found that with lowering only the downstream level leads to an increase in the discharge capacity of the labyrinth weir due to reducing the submergence effects at the outlet alveoli.
      PubDate: 2022-08-08
       
  • Detailed study of dimensioning and simulating a grid-connected PV power
           

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      Abstract: Abstract Climate problems and the need to reduce greenhouse gas emissions are driving researchers to find less polluting ways of generating electricity. One of the commonly used renewable energy sources is the sun, which is the basis for the use of photovoltaic (PV) energy to produce electricity through PV panels. In this context, based on the annual electricity consumption of the annex of the Faculty of Science in Rabat, we dimensioned the PV field needed to compensate this consumption as well as the global cost of this insultation, then using PVSYST we evaluated the annual electricity production and the percentage of power losses. The economic study determined the price per kWh and the payback period, and the environmental study showed that the use of this installation will save 6142 tCO2.
      PubDate: 2022-08-08
       
  • Modelling cropland expansion and its drivers in Trans Nzoia County, Kenya

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      Abstract: Abstract Population growth and increasing demand for agricultural production continue to drive global cropland expansions. These expansions lead to the overexploitation of fragile ecosystems, propagating land degradation, and the loss of natural diversity. This study aimed to identify the factors driving land use/land cover changes (LULCCs) and subsequent cropland expansion in Trans Nzoia County in Kenya. Landsat images were used to characterize the temporal LULCCs in 30 years and to derive cropland expansions using change detection. Logistic regression (LR), boosted regression trees (BRTs), and evidence belief functions (EBFs) were used to model the potential drivers of cropland expansion. The candidate variables included proximity and biophysical, climatic, and socioeconomic factors. The results showed that croplands replaced other natural land covers, expanding by 38% between 1990 and 2020. The expansion in croplands has been at the expense of forestland, wetland, and grassland losses, which declined in coverage by 33%, 71%, and 50%, respectively. All the models predicted elevation, proximity to rivers, and soil pH as the critical drivers of cropland expansion. Cropland expansions dominated areas bordering the Mt. Elgon forest and Cherangany hills ecosystems. The results further revealed that the logistic regression model achieved the highest accuracy, with an area under the curve (AUC) of 0.96. In contrast, EBF and the BRT models depicted AUC values of 0.86 and 0.77, respectively. The findings exemplify the relationships between different potential drivers of cropland expansion and contribute to developing appropriate strategies that balance food production and environmental conservation.
      PubDate: 2022-08-06
       
  • Urban flood susceptibility mapping in Ilorin, Nigeria, using GIS and
           multi-criteria decision analysis

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      Abstract: Abstract The objective of this study is to assess and map flood hazard zones in Ilorin (North-Central, Nigeria). Flood susceptibility zones were identified by utilizing the multi-criteria decision analysis (MCDA) technique integrated with Geographic Information System (GIS). Eight factors considered the most influential variables for runoff accumulation and stagnation in the city during excess rainfall and surface water runoff were taken into account. These factors include elevation, slope, topographic wetness index, convergence index, drainage density, altitude above channel, land use, and rainfall. To obtain the weights of each factor, the Analytical Hierarchical Process (AHP) was applied. The final flood hazard assessment and mapping were done using the Weighted Overlay operation. Essential findings of this study reveal that a critical percentage of the area (38.4%, corresponding to 127.01 km2) has a high flood risk. About 20.5% (67.85 km2) area shows moderate flood risk, while approximately 35.6% (117.77 km2) and 4.2% (13.98 km2) areas are identified as low and very low flood risk areas, respectively. The high flood risk zones need immediate attention because they are mostly found in the densely populated low-lying gentle slope (< 5o) areas. Accuracy assessment of the flood-hazard map indicates a considerable high value (87.5%). A combination of flood susceptibility and vulnerability has shown that about 35% of the metropolitan area is under the threat of high flood risk. The result of this study may be useful for the residents of the city, decision-makers, and urban planners for sustainable flood disaster planning and management in Ilorin.
      PubDate: 2022-08-06
       
  • Modelling COVID-19 in Senegal and China with count autoregressive models

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      Abstract: Abstract COVID-19 is a global health burden. We propose to model the dynamics of COVID-19 in Senegal and in China by count time series following generalized linear models. One of the main properties of these models is that they can detect potentials trends on the contagion dynamics within a given country. In particular, we fit the daily new infections in both countries by a Poisson autoregressive model and a negative binomial autoregressive model. In the case of Senegal, we include covariates in the models contrary to the Chinese case where the fitted models are without covariates. The short-term predictions of the daily new cases in both countries from both models are graphically illustrated. The results show that the predictions given by the negative binomial autoregressive model are more accurate than those given by the Poisson autoregressive model.
      PubDate: 2022-08-04
       
  • Soil erosion and sediment yield modeling for the Maruba dam catchment,
           Machakos County, Kenya

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      Abstract: Abstract Soil erosion and sediment yield modeling is important for reservoir management, especially in developing countries. Previous research has focused on spatial modeling of soil erosion in large catchments, particularly in Kenya. The purpose of this research was to predict soil erosion and sediment yield at the Maruba dam catchment. This study was carried out using the Revised Universal Soil Loss Equation for spatial modeling of soil erosion and reservoir sedimentation assessment using a bathymetric survey that utilized multi-frequency acoustics, and validated using sediment core data. According to the study, annual soil loss ranged from 0 to 29 t ha−1 yr−1, with an average of 0.9708 t ha−1 yr−1. The reservoir had a total capacity of 2,395,139.5 m3, a surface area of 256,622.85 m2, and a depth range of 0 to 13.5 m, according to the bathymetric survey. The reservoir’s overall sediment accumulation was calculated to be 290,434.6 m3, which corresponds to a 10.8% overall storage loss. It was estimated that the annual rate of reservoir capacity loss was 26,403.15 m3, or around 1%, which is in line with global averages. For the RUSLE-based and reservoir-based approaches, the sediment yields were estimated to be 0.1775 and 0.0054 t ha−1 yr−1, respectively. The variation in sediment yields demonstrated that the reservoir-based approach provided accurate estimates of sediment yields, especially in small catchments. The study’s findings provide crucial scientific information that would be helpful in formulating policies and making decisions on the management of dam reservoirs.
      PubDate: 2022-08-03
       
  • Hybrid particle swarm optimization and group method of data handling for
           short-term prediction of natural daily streamflows

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      Abstract: Abstract Hydrological forecasts have been developed since the earliest civilizations allowing to plan actions such as agriculture, grain storage, and the construction of reservoirs to supply water during long periods of drought. These forecasts are becoming increasingly essential given the growing dependence on water resources in the most diverse activities such as hydroelectric power generation. In this study, we develop a hybrid approach to forecasting the daily flow of the Zambezi River at the Cahora Bassa dam in Mozambique. These forecasts use daily historical data on flow, evaporation, relative humidity, and rainfall to predict the weather one day in advance. The model employs the seven past days as inputs to the Group Method of Data Handling (GMDH) algorithm optimized by the Particle Swarm Optimization (PSO) algorithm. GMDH is a neural network composed of neurons arranged in several layers, consisting of polynomial functions with two variables combined in a cascade to produce the output at the end of the network. The PSO promotes a search for optimal GMDH parameters to minimize the error values between the predicted and the actual river flow observed values. The simulations are performed 25 times to reduce the effects of the random values characteristic of the tested models. The results obtained by the proposed approach are compared with the other neural networks, such as extreme learning machine (ELM) and Multi-layer perceptron (MLP). The models’ performances were compared using five metrics, statistical tests, and uncertainty analysis. These results show that the GMDH model produced better flow prediction capability than the other two models.
      PubDate: 2022-08-03
       
  • Estimation of atmospheric chloride deposition using new model based on the
           theory of perfect gases

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      Abstract: Abstract Understanding atmospheric circulation is essential to study particle transport in the atmosphere. This applies to certain ions (chloride, sodium, calcium, sulfate, lead, and so on) as well as certain radio-elements (cesium, polonium, tritium, etc.…). The transfer factors are primarily controlled by atmospheric dispersion and diffusion. The spatial distribution and estimation of chloride deposits in precipitation are more than necessary for such use and quantification of recharge. The aim of this paper is to calculate the annual deposition of atmospheric chloride in the semi-arid area of Djelfa using a model derived from the perfect gas theory. This model, described as parsimonious, includes two basic parameters: rainfall and temperature. It is particularly useful in semi-arid areas with varying precipitation over time and space. Overall, this new numerical modeling approach emphasizes the importance of quantifying the distribution of chloride deposition in watersheds where data is frequently missing or scarce. Its implementation on site allowed the measurement of chloride mass deposition rates ranging from 1.52 to 31.70 g/m2/year with an average of 13.41 g/m2/year. Over the entire catchment area (1300 km2), the average annual deposit is around 13,500 tons/year.
      PubDate: 2022-08-03
       
  • A modeling approach for evaluating the impacts of Land Use/Land Cover
           change for Ziway Lake Watershed hydrology in the Ethiopian Rift

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      Abstract: Abstract Many parts of the Ethiopian Rift are undergoing significant Land Use/Land Cover (LULC) changes. In many places, the natural LULCs are converted into agricultural land to sustain the increasing food demand arising from a rapidly growing population. Modelling the responses of LULC changes on the hydrology of the area at the watershed scale is crucial for sustainable development of land and water resources. This study investigates the historic LULC change and its potential impacts on the hydrology of Ziway Lake Watershed in the Ethiopian Rift. Commonly, such assessments are accomplished by integrating physically based and semi-distributed hydrological model with Remote Sensing and Geographic Information System techniques. A hybrid LULC classification approach was applied to classify Landsat images of 1985, 1995, 2005 and 2020 and detect the LULC changes in the watershed. Subsequently, Soil and Water Assessment Tool was utilized to simulate the response of the hydrological process (water balance and stream flow) to LULC changes from 1985 to 2020. The image classifications of 1985, 1995, 2005 and 2020 revealed four LULC maps with eight LULC types. The relative change assessment results in the past 35 years from 1985 to 2020 revealed that the major expansion in Settlement, Cultivation and Agroforest resulting in a reduction of Woodlands. However, 58.3% of the watershed has remained intact while 41.7% has shown some degree of change. At the watershed level, these LULC changes had increased SURQ (87.07%), WYLD (31.86%) and ET (4.91%). Conversely, the observed change had reduced PERC (63.22%). But, the spatial analysis of the water balance components due to LULC changes were found to be non-uniform across the watershed. On the other hand, the seasonal stream flow analysis results indicated that Katar flow is increased by 15.36% and declined by 3.86% during the wet and dry seasons, respectively. Similarly, Meki flow showed a decrement during the dry seasons and an increment during the wet seasons by 7.04% and 20.66%, respectively. Beside the observed change, the results of the hypothetical LULC change scenarios justified a pronounced impact of historic LULC change on the water balance components of the watershed. These change in hydrological components and stream flow substantially attributed to the transformation of Woodland to agricultural land. Among the water balance components, the increment of SURQ may have a wider implication for increasing soil erosion and lake bed siltation. The continuous decline in PERC also highly affected the available groundwater resource of the watershed. The study will have significance for watershed managers and decision makers to improve the LULC and water management practices in the area by formulating mechanisms to maintain a sustainable hydrological balance in the watershed.
      PubDate: 2022-08-02
       
  • Experimental and numerical analyzes of parallel drains series performance
           in earth dams

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      Abstract: Abstract This paper aims to provide a tool for sizing the drain spacing and length of a series of parallel drains based on the geometry of the dam and the upstream water level. This technique, adopted for small dams not exceeding 15 m in height, has certain advantages such as ease of use, construction materials’ availability, and cost-effectiveness. Before checking the influence of the spacing and the length of the drains on the leakage rate, the interstitial pressure, the phreatic line, and the hydro-mechanical stability of the structure, experiments on a physical model made it possible to validate the numerical model. Experimental and Plaxis 3D results are in good agreement for flow rates and pore pressure. The numerical parametric study carried out for several combinations of spacing and length of the drains shows that the spacing of the drains depends on several parameters, such as the drain length, the embankment height, and the downstream slope. To minimize the leakage flow rate, the maximum length of the drains should not exceed one-third of the base of the backfill. The results of the numerical application on a real dam (reservoir of Oued El Magroune) by integrating the proposed drainage system and those with the existing drainage system (horizontal drain) show the reliability of this choice.
      PubDate: 2022-08-01
       
  • Adaptation of the revised universal soil loss equation (RUSLE) to soil
           loss modeling in a semi-arid watershed: a case study from western high
           atlas, Morocco

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      Abstract: Abstract Soil loss called also soil erosion is one of the most irreversible natural phenomena that affect the topsoil of Earth’s surface worldwide, as it causes soil fertility reduction, water availability decrease, and initiation of geo-hazards, which leads to negative repercussions on agricultural production, considered the main source of income for most of the autochthonous in the moroccan High Atlas. Due to its climatic and anthropogenic conditions, this region is considered one of the most vulnerable areas to soil erosion in Morocco, with consequential environmental and socioeconomic concerns. This study assesses soil loss in the upstream part of the High Souss watershed in the moroccan western High Atlas, using an integrated analysis of Remote Sensing, GIS, and the Revised Universal Soil Loss Equation (RUSLE). This assessment is based on the integration of different influencing factors: climate, soil erodibility, topography, vegetation cover, and soil conservation practices. Results reveal that the High Souss watershed is exposed to significant erosion, with an average soil loss of 57.27 t/ha/year and an annual erosion amount of 7.3 million tons. This rate is considered to be intensively high in the moroccan context. Moreover, areas subjected to intensive erosion risk are mainly located in the upstream part of the basin, where moderate to steep slope lands are concentrated. The used methodology and results have been compounded to facilitate the analysis of this risk, providing an important basis for government decision-makers, helping the design of meaningful conservation planning programs to reduce soil erosion and conserve natural resources, thus supporting regional development.
      PubDate: 2022-08-01
       
  • Soil loss assessment by RUSLE in the cloud-based platform (GEE) in Nigeria

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      Abstract: Abstract This study was conducted to predict annual soil loss at the district level in Nigeria for proper conservation measures. The method applied was the revised universal soil loss equation (RUSLE) and all factors used in RUSLE were calculated using Earth Engine’s public data archive. The pattern of soil loss was obtained using the spatial autocorrelation (Morans I) statistic. Ordinary least squares (OLS) linear regression model was used to estimate soil loss in terms of the relationships to its factors R, K, LS, C, and P. The grouping analysis tool was used to group districts based on soil loss. The results indicate that the estimated spatial average soil erosion was 7141 t ha−1 y−1 in Nigeria. The pattern of soil loss at the district level was found highly clustered with a z score of 10.045. The results obtained from linear regression were statistically significant p value (p < 0.01) and adjusted R-Squared (0.87). Twenty-six districts were identified in the very high category of soil loss based on standardized residuals above 1.5. The grouping analysis shows that the districts within groups 2 and 3 are in the outlier positions of soil loss due to the high LS factor. This work highlights valuable information for decision-makers and planners to take suitable land administration measures to minimize the soil loss in the districts of high soil loss. It, therefore, indicates Google Earth Engine is a significant platform to analyze the RUSLE model for evaluating and mapping soil erosion quantitatively and spatially.
      PubDate: 2022-07-31
       
  • Derivation of unit hydrograph using genetic algorithm-based optimization
           model

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      Abstract: Abstract The surface runoff can be predicted using hydrographs, and hence, the hydrographs become a prerequisite in designing hydrologic structures. The concept of unit hydrograph have been used widely in the field of hydrology in the past. There are different methods for the derivation of unit hydrographs like the ordinate method, matrix method, and the method of linear programming. In this study, a Genetic Algorithm-based optimization model has been created to identify the ordinates of unit hydrograph [U] to obtain a unique solution and avoid the challenges connected with the inversion of [P]T[P] matrix. The excess rainfall and direct runoff data sets are used to create an objective function for this purpose. The sum of the squares of the difference between the observed and the simulated direct runoffs is used to get the objective function. The simulated direct runoff values can be computed using the convolution equation [P][U] = [Q]. The Genetic Algorithm is then used to minimize the objective function in order to discover the ordinates of the unit hydrograph while taking into account, respectively, the 80%, 10%, and 10% of the total population size for elitism, crossover, and mutation. The root-mean-squared error of predicted values for three datasets obtained from the literature has been computed as 0.0126, 5.108, and 5.292.
      PubDate: 2022-07-27
       
  • Impact of initial conditions on modelling extreme precipitation: case of
           November 29–30, 2010 floods over Morocco

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      Abstract: Abstract Extreme Precipitation is a weather hazard that affects the society directly and harmfully. Because of the process involved in the formation of precipitation at several spatial and temporal scales, the forecast of precipitation is still challenging the weather models. The aim of this work is to evaluate the impact of initial condition on the modelling of extreme precipitation by the Numerical Weather Prediction (NWP) limited area model ALADIN (Aire Limitée Adaptation dynamique Developpement INternational) at 10 km horizontal resolution. The case study corresponds to the extreme flooding event of November 29–30, 2010 across Morocco with daily precipitation reaching 178 mm over Casablanca city. A detailed description of the atmosphere dynamic during this event is given to help the understanding of the precipitation generation. Several experiments were performed to assess the impact of conventional and satellite data. Furthermore, sensitivity studies were carried out for the surface initialisation and the start mode. The assimilation experiment with an optimal setting had produced dynamical fields that were more favourable for the heavy precipitation occurrence. The evaluation of precipitation forecast has been performed by comparison to the surface precipitation observations. The results showed that the combined surface/upper-air assimilation of both conventional and satellite observations produced a clear improvement in term of precipitation location and intensity forecast.
      PubDate: 2022-07-26
       
  • Evaluating the dynamics of hydroclimate and streamflow for data-scarce
           areas using MIKE11-NAM model in Bilate river basin, Ethiopia

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      Abstract: Abstract Dynamics of hydroclimatic factors in Bilate basin of Ethiopia have altered rainfall–runoff and hydrological processes. The objective is to generate streamflow in the area with restricted hydrometric data and predicting rainfall–runoff under varying climatic conditions. Limited study has been done on estimating streamflow in ungauged catchments due to lack of sufficient hydrometric information in this basin. Using multiple linear regression (MLR)-based regionalization and the deterministic, lumped, and conceptual hydrological MIKE11-NAM model, surface-runoff systems and river flow conditions have been studied elaborately. Hydro-climatic data from 1995 to 2020 were utilized as input to the model. The total stretch of years is distributed into three parts that includes the warm-up period (1995–1997), calibration (1997–2012), and the remaining for validation (2012–2020). Rainfall has been observed to be in decreasing order especially during the spring and summer. Streamflow in the basin is expected to decrease during the dry months due to decrease in precipitation and rise in temperature. During calibration and validation, the R2 values and water balance error were 0.83 and 4.9, and 0.76 and 8.6, respectively. The model’s average yearly flow during calibration is 253.9 mm/year. Streams originating from the northern, northwest, and southwest highlands feed the river with a maximum inflow of 188.86 m3/s, comprising of 44% of the basin’s mean annual streamflow. The basin’s central part has the lowest mean annual streamflow of 112.62 m3/s (26% of total flow). The average streamflow in the non-observable catchment is 130.37 m3/s over the years. The MIKE11-NAM model has an advantage over any other model when the landscape is rugged, inaccessible, and availability of limited data from the gauging stations.
      PubDate: 2022-07-25
       
  • Understanding the genesis of a dense fog event over Delhi using
           observations and high-resolution model experiments

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      Abstract: Abstract The present study aims to understand the three-dimensional structure of a dense fog event during the Winter Fog Experiment (WiFEX) 2016–2017 carried out at the Indira Gandhi International Airport (IGIA). The event is analysed with the help of ground-based measurements and the Weather Research and Forecasting (WRF) model. Sensitivity experiments were conducted using different initial conditions and compared to various observations. We find that higher resolution dynamical downscaling and the initial conditions from the Indian Institute of Tropical Meteorology’s Global Forecasting System (IITM-GFS) database yield satisfactory agreements with the observations carried out during the fog event. We note that a strong surface inversion layer exists in the model and observations before the fog onset. Once the fog forms, the simulations suggest that the fog layer grows vertically, destabilizing the temperature stratification. The intensity of the longwave radiative cooling near the fog top increases as the fog grows vertically and shows maximum liquid water content (LWC) near the fog top. The vertical evolution of fog in the model is well identified by the intensity of turbulent kinetic energy (TKE), which is low before the development of dense fog and endures more TKE as the fog becomes dense and vertically thick. The results demonstrate that the WRF model captures the complexity of the physical process and their interaction during the fog evolution in a manner that can be explored further to improve the accuracy of the operational fog forecast.
      PubDate: 2022-07-25
       
  • The effect of growth compounds with different doses on physiological
           characteristics of rice in the treasury

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      Abstract: Abstract To examine the effect of application of humic acid, folic acid, and seeding treatment with various levels of phosphorous compounds on vegetative characteristics, yield and nutrient uptake capacity of rice (Tarom cultivar) in the nursery at different sowing dates, a split-split plot experiment in a randomized complete block design (RCBD) was performed with three replications in Sari in 2017 and 2018. Experimental factors included an equal combination of humic acid and folic acid as the main factor in the four levels of control and, 3, 6 and 9 g/l, the combination of phosphoric acid solution and monoammonium phosphate as the sub-factor in the four levels of control and 5, 10 and 15 g/l, and the planting date as a sub-sub-factor in three levels in March 10th, March 19th and March 30th. The results revealed that the application of humic acid and folic acid increased root length and the wet and dry weight of the plant compared with the control, and the greatest effect was obtained in the treatment of 6 g/l humic acid and folic acid. The application of humic acid and folic acid caused an increase in the grain and straw nitrogen and the grain phosphorus content but a decrease in the straw phosphorus content. Feeding the seedlings with phosphorus compounds led to a significant increase in the root length and the wet and dry weight of the plant compared with the control. The greatest effect was observed in the treatment of 10 g/l of different phosphorus compounds. Feeding the seedlings with phosphorous compounds increased the nitrogen and phosphorus contents of the grain and straw. Also, the maximum root length and the wet and dry weights of the plant were obtained on the planting dates of March 10th and 19th. In general, it was observed that the greatest dry weight of the plant was 1.017 g, belonging to the treatment of consumption of 6 g/l humic acid and folic acid with 10 g/l of various phosphorus compounds planted on March 10th. The highest amount of white rice (64.18%) was related to the treatment of 10 g/l phosphorus. On planting date, 24 April, more white rice (63.59%) was obtained than the planting dates of 14 April (62.34%) and 4 May (61.28%). The simple correlation between the measured traits showed that the amount of white rice had a positive and significant correlation (at the level of 1% probability) with all measured traits except gel consistency and hard rice and had a significant negative correlation with a gel consistency and hard rice husk.
      PubDate: 2022-07-21
       
 
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