- Reservoir management under predictable climate variability and change
- Authors: Ahmad Asnaashari; Bahram Gharabaghi, Ed McBean Ali Akbar Mahboubi
Abstract: The potential effects of climate change on future water budget components and streamflow in the Mississippi River (Ontario) are assessed. Analyses of historic hydrometric data indicate an increasing trend in winter streamflows due to the rising winter air temperatures across the region over the latter half of the 20th century. These temperatures have resulted in reduced snow accumulation and earlier spring snowmelt. Projected future climate data are developed using the second generation Coupled Global Climate Model and downscaled using the change factor method for the Mississippi River watershed (Ontario). The projected future climate data are then used as input to a calibrated hydrologic model for simulation of future water balance and streamflows in this river basin. These simulations predict a gradual annual rate of change of: 0.1% increase in total precipitation; 0.2% increase in rainfall; 0.7% decrease in snowfall; 0.2% increase in potential evapotranspiration; 0.1% decrease in soil moisture; 1.4% increase in water deficit; 0.5% increase in streamflow during winter months; and 0.3% decrease in summer streamflows. Cyclic pattern analysis of the historic streamflow records suggests the existence of pronounced 3-year and 12-year cycles, providing short-term streamflow forecasting opportunities for optimum reservoir management operations during the wet-year/dry-year cycles.
- Adaptive capacity of commercial real estate firms in New York City to
- Authors: Jesse M. Keenan
Abstract: This article examines the adaptive capacities of real estate firms in New York City in light of the increased risks of urban flooding. This exploratory research attempts to shed light on how and why firms of varying risk profiles are strategically adapting to these risks – if at all. Through the lens of a qualitative multi-criteria adaptive capacity framework, the results of six case studies are analyzed to identify what influences are shaping the actions and strategies of firms. The article examines the propositions that: (A) firms with observable strategies have undertaken ex post strategies which are principally driven by the firms’ financial bottom line; (B) firm strategies attribute little to no influence in their decisions to external or delayed costs and/or impacts relating to social and environmental influences; and, (C) firms with the comparatively most robust adaptive capacities will be those who: (i) are most aware of their vulnerabilities; and (ii) are themselves comparatively more vulnerable to the immediate risks associated with urban flooding. While the evidence largely supports the propositions, the results of this research can help shape the development of intelligence and strategic units within firms as they develop a capacity to adapt to ever changing conditions.
- Wavelet-based trend analysis of hydrological processes at different
- Authors: Vahid Nourani; Nasrin Nezamdoost, Maryam Samadi Farnaz Daneshvar Vousoughi
Abstract: This study analyzes involved trends in stream flow and precipitation data at monthly, seasonal and annual timescales observed at six precipitation and four stream flow stations of Tampa Bay using non-parametric Mann–Kendall (MK) and discrete wavelet transform (DWT) methods. The MK test and sequential MK analysis were applied to different combinations of DWT after removing the effect of significant lag-1 serial correlation to calculate components responsible for trend of the time series. Also, the sequential MK test was used to find the starting point of changes in annual time series. The results showed that negative trend is prevalent in the case study; generally, short-term periods were important in the involved trend at original time series. Thus, the precipitation data at three scales showed short-term periods of 2 months, 6 months and 2 years in monthly, seasonal and annual scales, respectively. In the greatest stream-flow time series at three timescales, wavelet-based detail at level 2 plus the approximations time series was conceded as the dominant periodic component. Finally, the results of Sen's trend analysis, applied to the original annual time series, also confirmed the results of the proposed wavelet-based MK test in most cases.
- The evolution of organic character in a drought- and flood-impacted water
source and the relationship with drinking water treatment
- Authors: Rolando Fabris; Kalan Braun, James Y. Morran, Lionel Ho Mary Drikas
Abstract: A pilot-scale research investigation examining treatment technologies including coagulation, ion-exchange, activated carbon and membrane filtration and their impact on water quality coincided with a period of extensive variability in source water character. Distinct water quality periods as a result of extreme climatic conditions from drought to flood were observed and the natural organic matter (NOM) removal examined using a suite of organic characterisation techniques from simple ultraviolet (UV) absorbance to more advanced spectroscopic and chromatographic methods. The low specific UV absorbance (SUVA) and apparent molecular weight (AMW) distribution of the drought-impacted NOM was recalcitrant to coagulation with significant improvement in NOM removal resulting from the multi-step treatments. Among a number of discernible changes, floodwaters introduced high AMW, UV-absorbing NOM of terrestrial origin, which was shown to be more amenable to coagulation. Nevertheless the application of multi-step treatments resulted in further reduction in both the concentration and diversity of organic components. Filtration through granular activated carbon was observed to be the most variable treatment technology across the investigated period due to diminishing adsorption capacity. Conversely, the dual stage membrane filtration was shown to remove a broad range of organic matter, regardless of source water NOM concentration and character.
- Assessing climate change impact on root-zone water balance and groundwater
- Authors: Samanpreet Kaur; S. K. Jalota, K. G. Singh, Prit Pal Singh Lubana Rajan Aggarwal
Abstract: The present study employs regional climate model projections for assessing the impact of root-zone water balance and groundwater levels using crop and groundwater models. The projections from Hadley Regional Model 3 (HRM3) for A1B scenario showed an increase in temperature and rainfall (RF) of 1.8 °C and 328 mm, respectively, during mid-century (MC) (2021–2050) for Indian central Punjab. The respective increase in values for the end of century (2071–2098) would be 4.4 °C and 486 mm, compared with present time slice (PTS) (2000–2010). In future, irrigation requirement would reduce, because of increased RF and decreased transpiration from cropped area owing to a shortening of crop duration of rice-wheat cropping system with temperature. The reduced irrigation need in future would decrease groundwater withdrawal resulting in the rise of groundwater level.
- Modeling the impacts of climate change and future land use variation on
- Authors: Rory Coffey; Brian Benham, Karen Kline, Mary Leigh Wolfe Enda Cummins
Abstract: The impact of waterborne micro-organisms (potentially pathogenic) on public health may be exacerbated by the combined effects of climate and land use change. We used watershed modeling to assess the potential effects of climate change and future land management scenarios on microbial water quality in the Pigg River watershed, located in southwest Virginia, USA. The hydrologic simulation program in Fortran, climate forecasts from the Consortium for Atlantic Regional Assessment, future projections for land management, and current watershed data were used to simulate a range of potential future scenarios for the period 2040–2069. Results indicate that changes in climate will have the most significant impact on microbial fate and transport, with increased loading driven by trends in seasonal and annual precipitation. High flow and low flow periods represent periods of greatest uncertainty. As climate factors are to an extent uncontrollable, adaptation measures targeting land based source loads will be required to maintain water quality within existing regulatory standards. In addition, new initiatives may need to be identified and incorporated into water policy. This is likely to have repercussions for all watershed inhabitants and stakeholders, but will assist in sustaining water quality standards and protecting human health.
- Toward an innovative interdisciplinary method for vulnerability
assessments: the case of Taiwan
- Authors: Chia-Chi Lee; Ching-Pin Tung, Tzu-Ming Liu, Jung-Hsuan Tsao, Gin-Rong Liu, Yi-Chang Chiang Kuo-Ching Huang
Abstract: Humans live in complicated social-ecological systems within which we interact with our surrounding environment. This interaction is of concern to various disciplines, which focus on various system elements (factors), many of which are mutually interacting. Assessments of vulnerability to climate change assist us in realizing the magnitude of the impact of various climate change factors, allowing us to determine and adopt appropriate adaptation measures. Nevertheless, previous impact-driven vulnerability assessments are either disciplinary or multidisciplinary and cannot easily account for the interaction between different disciplines. This paper proposes an interdisciplinary vulnerability assessment method (IVAM) to develop a framework by which interdisciplinary vulnerabilities can be understood. In addition, IVAM processes can promote the emergence of an interdisciplinary system, which could be used to identify the scope of interdisciplinary influence of a particular policy, along with the critical elements (factors) and government stakeholders of such policies. This research seeks to further the policy goals of the national government of Taiwan vis-à-vis climate change, covering the joint cooperation of experts from fields including environmental disaster management, public health, food security, ecology, and water resource management. The specific advantage of IVAM, however, is that this universal model is not limited to any of these specific disciplines.
- Vulnerability of Mexico City's water supply sources in the context
of climate change
- Authors: Sandra Martinez; Stefanie Kralisch, Oscar Escolero Maria Perevochtchikova
Abstract: In the context of growing urbanization and climate change, the issue of how to best secure and increase future water supply in developing countries is key. To support informed decision-making in Mexico City, a comprehensive study was conducted to assess the potential effects of climate change and the vulnerability of water sources. The infrastructural, environmental and administrative factors affecting the water available from each source were identified and evaluated, and then combined with the likely impacts in regional water availability estimated using results from two global circulation models and two emission scenarios. The results obtained indicate that the water sources outside Mexico City, such as the Cutzamala and Lerma systems, are the most vulnerable. The current situation is likely to become worse as a result of climate change, as projections suggest a 10–17% reduction in water availability by 2050. When responsible agencies decide the strategies to secure and increase water supply, they will have to consider the prevailing and potential conflicts, the local water demand, the contribution to the city's greenhouse gas emissions and future changes in water availability.
- Trend analysis in climatic variables and impacts on rice yield in Nigeria
- Authors: C. O. Akinbile; G. M. Akinlade A. T. Abolude
Abstract: The effects of changes in meteorological parameters on rice yield variations were considered. Weather parameters, temperature (T), rainfall (R), relative humidity (RH) and solar radiation (SR), and rice yield variation for Ibadan were analyzed. Meteorological parameters were obtained from the International Institute for Tropical Agriculture while rice yield data were obtained from the Africa Rice Centre both in Nigeria for three decades (1980–2010). Trends analysis of past and recent variations using the weather parameters obtained showed trends of variability of each parameter with respect to rice yield. Mann–Kendall trend and Sen's slope tests were performed on the respective meteorological variables while correlation, multiple regression and variability index (VI) were also computed for these parameters. Results showed that T, RH and rice yield were negative and decreased significantly (P < 0.001) while R and SR showed statistically non-significant increasing trends in the last three decades. R and T decreased at the rate of 3% per year and 0.03% per decade, respectively. Results of annual VI showed that decreases observed in RH, SR and rice yield were rather recent. T, SR and R were found to have the most significant effect on rice yield of all the meteorological parameters considered.
- Thermal stratification of Portuguese reservoirs: potential impact of
extreme climate scenarios
- Abstract: Changes in water temperature and stratification dynamics can have a significant effect on hydrodynamics and water quality in reservoirs. Therefore, to assess future climate impacts, projections of three regional climate models for Europe, under the IPCC A1B emission scenario (2081–2100), were used with the CE-QUAL-W2 water quality model to evaluate changes in the thermal regime of 24 Portuguese reservoirs, representing different geographic regions, morphologies, volumes and hydrological regimes. Simulation results were compared with reference simulations for the period 1989–2008 and changes in water temperature and thermal stratification characteristics were evaluated. Future inflow scenarios were estimated from precipitation-runoff non-linear correlations and outflows were estimated considering present water uses, including hydropower, water supply and irrigation. Results suggest a significant increment in the mean water temperature of the reservoirs for the entire water volume and at water surface of 2.3 and 2.5 °C, respectively, associated with a runoff reduction of approximately 23%. Overall, variations in annual stratification patterns are characterized by changes in the mean annual length of stratification anomaly that ranged from −21 to +39 days. Results also show the influence of depth and volume over the reservoir's temperature anomaly, highlighting the importance of future water uses and operation rule curves optimization for reservoirs.
- Using climate scenarios to evaluate future impacts on the groundwater
resources and agricultural economy of the Texas High Plains
- Authors: Rachna Tewari; Jeff Johnson, Steven Mauget, Gary Leiker, Katharine Hayhoe, Annette Hernandez, Darren Hudson, Chenggang Wang, Dennis Patterson Ken Rainwater
Abstract: This study evaluated the impacts of future climate scenarios on the groundwater resources and agricultural economy of the Texas High Plains, using Hale county as a case study. Climate change impacts were incorporated into regional economic models using weather projections to develop crop response functions from crop models. These projections are based on quantitative projections of precipitation, potential evapotranspiration, and temperature trends driven by simulations from the latest IPCC AR4 climate models (Community Climate System Model (CCSM), Geophysical Fluid Dynamics Laboratory (GFDL), UK Met Office Hadley Model (HadCM3), and Parallel Climate Model (PCM)) under two specific emissions scenarios, A1B (mid-range) and A1FI (higher). Results indicated that for both the emission scenarios, saturated thickness, water use per cropland acre, and irrigated acreage declined under climatic predictions by all four models. At the end of the 90 year horizon, the A1B scenario resulted in a decline in average net income per acre as predicted by the CCSM and HadCM3 models, while the GFDL and PCM models predicted an increase in average net income per acre. Under the A1FI scenario, the CCSM, GFDL, and PCM model projections led to increased average net income per acre, while climate projections under the HadCM3 model indicated a decline in average net income per acre at the end of the 90 year horizon.
- Relationship between solar activity and flood/drought disasters of the
Second Songhua river basin
- Authors: Li Hong-yan; Xue Li-jun Wang Xiao-jun
Abstract: Based on the direct correlation method, this paper analyzes the correlation of sunspot number (SSN) and western Pacific subtropical high (WPSH) ridge index with flood/drought disasters in the Second Songhua River (SSHR) basin, combined with long sequences of SSN, WPSH ridge index, precipitation and other data. Results show that SSN is clearly correlated with flood/drought disasters, what is more, flood years mainly appear in three phases: Solar Maximum Year, years after Solar Maximum Year and Solar Minimum Year. In addition, there is an alternate change of flood/drought with a 10-year cycle. This paper uses the commensurable method to identify the periods of floods and droughts in the study area. According to the commensurable diagram, catastrophic nodes of the future floods or droughts in SSHR basin can be primarily predicted as follows: 2021 will be a flood year, while 2013, 2016 and 2024 will be high flow years; 2012 and 2022 will be dry years, while 2014, 2018 and 2027 will be low flow years. Moreover, forecast accuracy of flood/dry years is higher than the one of high/low flow years. Prediction of flood/drought has an error of ±1 year, which can be tracked and corrected with a scatter diagram.
- Efficiency of maize irrigation scheduling in climate variability and
extreme weather events in eastern Croatia
- Abstract: This study was conducted (2010–2012) to analyse the efficiency of irrigation scheduling in maize production based on soil moisture measurements (Watermark soil moisture sensors) in years with extreme weather events at the research site of the Agricultural Institute in Osijek, eastern Croatia. Three irrigation treatments and four maize hybrids were studied. In the extremely rainy 2010, the highest yield of maize grain was obtained in rainfed plots (control = 9.24 t ha−1). A significantly (P < 0.01) lower yield (−8%) was obtained in fully irrigated plots (a3 = 8.59 t ha−1). This was opposite to the results obtained from the extremely warm 2011 and very dry 2012, when grain yield was higher as the amount of irrigation water was increased. Maize grain yield in the fully irrigated plot was 25% (2011) and 40% (2012) higher compared with the control plots (dryland). According to our results, the main factor for irrigation efficiency in extreme weather conditions is to properly determine the optimum level for soil moisture sensors and ground water level in relation to root depth.
- Evaluation of climate change impacts and adaptation strategies for maize
cultivation in the Himalayan foothills of India
- Authors: Proloy Deb; Anthony S. Kiem, Mukand S. Babel, Sang Thi Chu Biplab Chakma
Abstract: This study evaluates the impacts of climate change on rainfed maize (Zea mays) yield and evaluates different agro-adaptation measures to counteract its negative impacts at Sikkim, a Himalayan state of India. Future climate scenarios for the 10 years centered on 2025, 2055 and 2085 were obtained by downscaling the outputs of the HadCM3 General Circulation Model (GCM) under for A2 and B2 emission scenarios. HadCM3 was chosen after assessing the performance analysis of six GCMs for the study region. The daily maximum and minimum temperatures are projected to rise in the future and precipitation is projected to decrease (by 1.7 to 22.6% relative to the 1991–2000 baseline) depending on the time period and scenarios considered. The crop simulation model CERES-Maize was then used to simulate maize yield under future climate change for the future time windows. Simulation results show that climate change could reduce maize productivity by 10.7–18.2%, compared to baseline yield, under A2 and 6.4–12.4% under B2 scenarios. However, the results also indicate that the projected decline in maize yield could be offset by early planting of seeds, lowering the farm yard manure application rate, introducing supplementary irrigation and shifting to heat tolerant varieties of maize.
- Analysis of monsoon rainfall variability over Narmada basin in central
India: Implication of climate change
- Authors: T. Thomas; S. S. Gunthe, N. C. Ghosh K. P. Sudheer
Abstract: Daily rainfall of 23 high resolution (1° × 1°) grid cells covering the Narmada basin has been analyzed to investigate the trend in extreme rainfall events. The trend analysis of the 1-day maximum rainfall series showed a significant positive trend at 95% significance level with the Mann–Kendall test statistic value of z = 3.66 over the entire basin. The analysis further suggested that there has been an increasing trend in the magnitude of 1-day maximum rainfall over the basin with more areas in the basin experiencing high intensity storms, which was more prominent in the most recent 20 years. Drought duration estimated by the standardized precipitation index for the periods 1951–1970 and 1989–2008 indicated that the entire basin has experienced frequent droughts during the recent two decades, with the middle zone of the basin being more prone to droughts. The analysis also suggested that appropriate measures may be proposed for better management of the water resources in the basin, and also for mitigation of floods and droughts, considering the increased risk of the high intensity storms as well as the increased frequency of drought occurrence during the recent two decades.
- A case study of regional risk assessment of river restoration projects:
Nakdong River Basin, South Korea
- Authors: Jong-Suk Kim; Sun-Kwon Yoon, Minha Choi Young-Il Moon
Abstract: An integrated approach to risk assessment that can pose significant challenges to mitigation and adaptation at the local or regional levels in the context of climate change was developed. First, a conceptual framework for flood risk analysis was developed based on the hydrologic hazard and the socioeconomic vulnerability of a region. Second, weighting factors for each indicator were estimated using the modified Delphi approach based on the results of a survey of an expert group. Third, geographic information system analysis described the hydrologic risk at the regional level before and after completion of the Four Major Rivers Restoration Project at the Nakdong River Basin, South Korea. Finally, sensitivity analysis was conducted to evaluate the extent of the resilience of the Nakdong River Basin based on climate change scenarios to extend the existing research. It was found that the effect of the river restoration project in the future would be insignificant in terms of risk control over regions where floods are likely to increase upon climate change. We believe that this study provides useful information for the development of scientific, effective risk management tools for consistent application in a time of changing climate.
- April–June precipitation reconstruction for Xi'an and
drought assessment for the Guanzhong Plain from tree rings of Chinese pine
- Authors: Feng Chen; Yujiang Yuan, Wenshou Wei, Ziang Fan, Ruibo Zhang Shulong Yu
Abstract: Variations in earlywood width (EWW) of Chinese pine in the Nanwutai Mountain were used to develop high-resolution climate proxy data to extend existing climate records in Guanzhong Plain, Shaanxi Province, China. Growth–climate response analyses showed the EWW series in Nanwutai Mountain are mainly influenced by spring and early summer precipitation. Based on the EWW series derived from the Nanwutai Mountain, we developed an April–June precipitation reconstruction for Xi'an for the period 1800–2009. The climate/tree-growth model accounts for 36.4% of the instrumental precipitation variance during the period 1951–2009. Spatial climate correlation analyses with the gridded precipitation data revealed that our precipitation reconstruction contains a strong regional precipitation signal for the Guanzhong Plain. Our reconstruction successfully captured recent climatic changes and agreed, in general, with other tree-ring-based precipitation reconstructions from nearby regions on a decadal timescale. The rainfall/drought series in northern China also showed highly synchronous decreasing trends since the 1970s, suggesting that precipitation related to the East Asian summer monsoon has decreased by large spatial and temporal (decadal) scales. In addition, wavelet analysis revealed the existence of some decadal (13.3-year) and interannual (9.1-, 5.4-, 3.1-, and 2.1-year) cycles, which may potentially be the fingerprints of some proposed climate change forcings, such as El Niño-Southern Oscillation and solar activities.
- Climate change impact on rainfall and temperature in Muda irrigation area
using multicorrelation matrix and downscaling method
- Authors: Nurul Nadrah Aqilah Tukimat; Sobri Harun
Abstract: Statistical downscaling model was used to generate 30-year climate trend of Kedah – the state which has the largest cultivation area in Malaysia, resulting from climate changes. To obtain a better predictors set, multicorrelation matrix analysis was added in the climate model as a screening tool to explain the multiple correlation relationship among 26 predictors and 20 predictands. The performance of the predictor set was evaluated statistically in terms of mean absolute error, mean square error, and standard deviation. The simulation results depict the climatic changing trend in this region in terms of temperature, rainfall, and wet and dry length compared to historical data captured from 1961 to 2008. Annual temperature and rainfall depth are expected to increase 0.2 °C per decade and 0.9% per year, respectively, from the historical record. The months of November and January are expected to receive the highest and lowest rainfall depth, respectively, because of the two monsoon seasons. The wet spell is estimated to be from May to November in the middle of Kedah. The annual dry spell shall be from January to March, and is expected to shorten yearly.