Your search found 62 records
1 Pandey, B. K.; Khare, D.; Kawasaki, A.; Meshesha, T. W. 2021. Integrated approach to simulate hydrological responses to land use dynamics and climate change scenarios employing scoring method in Upper Narmada Basin, India. Journal of Hydrology, 598:126429. [doi: https://doi.org/10.1016/j.jhydrol.2021.126429]
Climate change ; Land use change ; Land cover ; Hydrological modelling ; River basins ; Water availability ; Water balance ; Evapotranspiration ; Precipitation ; Temperature ; Meteorological factors ; Forecasting ; Discharges ; Vegetation ; Uncertainty / India / Narmada Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050469)
(11.20 MB)
Accurate spatial and temporal measurement of water budget play a crucial role in achieving the sustainable planning and management of water resources. This paper presents a comprehensive integrated approach to simulate hydrological responses under dynamics of land use land cover (LULC) and climate change scenarios over Upper Narmada Basin, India. In order to select the representative climate models, scoring method was applied at regional scale. Best five performing climate models (MIROC5, CNRM-CM5, MPI-ESM-LR, GFDL-ESM2G and IPSL-CM5A-MR) were coupled with semi-distributed hydrological model to simulate the hydrological responses. Considering the heterogeneity of the large basin, multi-site calibration and parameters sensitivity analysis were performed using Sequential Uncertainty Fitting (SUFI-2) algorithm. To compute the hydrological sensitivity against land use change, calibrated model was coupled with historical and futuristic land use scenarios (1990, 2000, 2010 and 2030). The results indicate intensified precipitation towards the late 21st century, whereas annual mean temperature could be raised by 1.79 °C and 3.57 °C under mid and high emission scenarios respectively, at the end of century. Annual and monsoon flow in the basin likely to increase during the 2050 s (2041–2070) and 2080 s (2071–2100). Moreover, the relation between climate variables and water budget components were identified to analyse the hydrological sensitivity of the basin under changing climate.
2 Tamiru, H.; Dinka, M. O. 2021. Application of ANN [Artificial Neural Networks] and HEC-RAS model for flood inundation mapping in Lower Baro Akobo River Basin, Ethiopia. Journal of Hydrology: Regional Studies, 36:100855. [doi: https://doi.org/10.1016/j.ejrh.2021.100855]
Flooding ; Mapping ; Hydrological modelling ; Neural networks ; Machine learning ; River basins ; Runoff ; Forecasting ; Rain ; Training / Ethiopia / Baro Akobo River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050485)
https://www.sciencedirect.com/science/article/pii/S2214581821000847/pdfft?md5=1534edf821b5ee38fa5413516a807b08&pid=1-s2.0-S2214581821000847-main.pdf
https://vlibrary.iwmi.org/pdf/H050485.pdf
https://vlibrary.iwmi.org/pdf/H050485.pdf
(7.58 MB) (7.58 MB)
Study region: Lower Baro River, Ethiopia.
Study focus: This paper presents the novelty of ANN and HEC-RAS model for flood inundation mapping in lower Baro Akobo Basin River, Ethiopia. ANN and HEC-RAS model is applied and successfully improves the accuracy of prediction and flood inundation in the region. This study uses 14 meteorological stations on a daily basis for 1999-2005 and 2006-2008 periods, and Topographical Wetness Index (TWI) to the train and test the model respectively. The runoff time series obtained in ANN model is linked to HEC-RAS and the flood depths were generated. The flood inundation generated in HEC-RAS model result was calibrated and validated in Normal Difference Water Index (NDWI).
New hydrological insights for the region: As the inundation map generated from the runoff values of ANN model reveals, the lower Baro river forms huge inundation depth up to 250 cm. The performance the ANN model was evaluated using Nash-Sutcliffe Efficiency (NSE = 0.86), PBIAS = 8.2 % and R2 = 0.91 and NSE = 0.88, PBIAS = 8.5 % and R2 = 0.93 during the training and testing periods respectively. The generated inundation areas in HEC-RAS and the water bodies delineated in NDWI were covered with 94.6 % and 96 % as overlapping areas during the calibration and validation periods respectively. Therefore, it is concluded that the integration of the ANN approach with the HEC-RAS model has improved the prediction accuracy in traditional flood forecasting methods.
Study focus: This paper presents the novelty of ANN and HEC-RAS model for flood inundation mapping in lower Baro Akobo Basin River, Ethiopia. ANN and HEC-RAS model is applied and successfully improves the accuracy of prediction and flood inundation in the region. This study uses 14 meteorological stations on a daily basis for 1999-2005 and 2006-2008 periods, and Topographical Wetness Index (TWI) to the train and test the model respectively. The runoff time series obtained in ANN model is linked to HEC-RAS and the flood depths were generated. The flood inundation generated in HEC-RAS model result was calibrated and validated in Normal Difference Water Index (NDWI).
New hydrological insights for the region: As the inundation map generated from the runoff values of ANN model reveals, the lower Baro river forms huge inundation depth up to 250 cm. The performance the ANN model was evaluated using Nash-Sutcliffe Efficiency (NSE = 0.86), PBIAS = 8.2 % and R2 = 0.91 and NSE = 0.88, PBIAS = 8.5 % and R2 = 0.93 during the training and testing periods respectively. The generated inundation areas in HEC-RAS and the water bodies delineated in NDWI were covered with 94.6 % and 96 % as overlapping areas during the calibration and validation periods respectively. Therefore, it is concluded that the integration of the ANN approach with the HEC-RAS model has improved the prediction accuracy in traditional flood forecasting methods.
3 Ndhlovu, G. Z.; Woyessa, Y. E. 2021. Use of gridded climate data for hydrological modelling in the Zambezi River Basin, southern Africa. Journal of Hydrology, 602:126749. (Online first) [doi: https://doi.org/10.1016/j.jhydrol.2021.126749]
Hydrological modelling ; Climatic data ; River basins ; Water resources ; Hydrometeorology ; Stream flow ; Water yield ; Land use ; Land cover ; Precipitation ; Rain ; Sensitivity analysis ; Uncertainty / Southern Africa / Zambezi River Basin / Kabompo River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050589)
(3.81 MB)
The Zambezi River Basin is among many basins in Southern African region with inadequate, low resolution, poorly maintained and distributed network of hydrometeorological stations. This scenario entails scarcity of hydrological data in the basin and subsequently leads to poor assessment of water resources. This paper investigates alternative technologies in the assessment of the hydrology and water resources in the basin. The high-resolution gridded climate data together with land use and soil data were used as inputs into SWAT model to simulate hydrological processes. Calibration and validation of model were performed using SWAT-CUP. Comparison of average monthly rainfall data for gridded and observed shows 97% correlation. The statistics show NS to be 0.73 while R2 was 0.73. The uncertainty analysis was determined with a P-factor at 0.75 while the R-factor was 0.75. Therefore, use of gridded climate data for hydrological modelling in data scarce regions could be a useful tool to estimate the main hydrological parameters and water resources of an area with satisfactory accuracy.
4 Galata, A. W.; Tullu, K. T.; Guder, A. C. 2021. Evaluating watershed hydrological responses to climate changes at Hangar Watershed, Ethiopia. Journal of Water and Climate Change, 12(6):2271-2287. [doi: https://doi.org/10.2166/wcc.2021.229]
Watersheds ; Hydrological modelling ; Climate change ; Forecasting ; Precipitation ; Temperature ; Water resources ; Runoff ; Greenhouse gas emissions ; Land use ; Land cover ; Sensitivity analysis ; Uncertainty / Ethiopia / Hangar Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H050699)
https://iwaponline.com/jwcc/article-pdf/12/6/2271/934942/jwc0122271.pdf
https://vlibrary.iwmi.org/pdf/H050699.pdf
https://vlibrary.iwmi.org/pdf/H050699.pdf
(0.90 MB) (916 KB)
The aim of this study is to model the responses of Hangar Watershed hydrology to future climate changes under two representative concentration pathway (RCP) scenarios. Future changes in precipitation and temperature were produced using the output of dynamically downscaled data of a regional climate model (RCM) 0.44° resolution under RCP 4.5 and 8.5 scenarios for 2025–2055 and 2056–2086. The future projection of the RCM model of precipitation and temperatures showed an increasing trend relative to the base period (1987–2017). At 2025–2055 average annual precipitation increments of +15.7 and +19.8% were expected for RCP 4.5 and RCP 8.5, respectively. For 2056–2086 of RCP 4.5 and 8.5, a similar trend was also shown as average annual precipitation may increase by +20.1 and +23.4%, respectively. The changes of climate parameters were used as input into the SWAT hydrological model to simulate the future runoff at Hangar Watershed. The increment in precipitation projection resulted in a positive magnitude impact on average runoff flow. The average annual change in runoff at 2025–2055 of both RCP 4.5 and 8.5 may increase by +24.5 and +23.6%, respectively. In 2056–2086, a change in average annual runoff of +73.2 and +73.2% for RCP 4.5 and 8.5 may be expected, respectively.
5 Makungu, E.; Hughes, D. A. 2021. Understanding and modelling the effects of wetland on the hydrology and water resources of large African river basins. Journal of Hydrology, 603(Part C):127039. [doi: https://doi.org/10.1016/j.jhydrol.2021.127039]
River basins ; Water resources ; Wetlands ; Hydrological modelling ; Floodplains ; Uncertainty / Africa / Zambia / Zambezi River Basin / Luangwa River Basin / Luangwa Floodplain / Barotse Floodplain
(Location: IWMI HQ Call no: e-copy only Record No: H050822)
https://www.sciencedirect.com/science/article/pii/S0022169421010891/pdfft?md5=13945e03aef2e1362c10fd16ef7e3a3b&pid=1-s2.0-S0022169421010891-main.pdf
https://vlibrary.iwmi.org/pdf/H050822.pdf
https://vlibrary.iwmi.org/pdf/H050822.pdf
(6.51 MB) (6.51 MB)
Wetlands are important components of many large river systems. Some basin scale hydrological models do include explicit sub-models to deal with wetland impacts, but one of the key challenges is to estimate appropriate parameter values to represent the channel-wetland exchange processes. A combined modelling approach is applied in this study and involves the use of the detailed, daily time-step, LISFLOOD-FP hydraulic model to improve the understanding of channel-wetland exchange dynamics and to quantify the wetland parameters of a basin scale hydrological model. While there remain, many uncertainties associated with a lack of sufficient validation data, the LISFLOOD-FP results largely reflect the physical characteristics of the two floodplains (the Luangwa and Barotse in the Zambezi River basin). The LISFLOOD-FP results were also used to estimate the wetland parameters of the basin scale hydrological model with greater confidence and improved the downstream simulations results (albeit marginally). The results suggest that the influence of the floodplain on the monthly Luangwa flow regime is minimal, whereas the Barotse floodplain significantly attenuates the high flows and regulates the low flows of the Upper Zambezi River. The approach implemented in this study presents an important step towards the improvements of water resource assessments modelling for research and practical purposes in data-scarce river basins, however, further work is required to refine the model setup using additional field information related to exchange dynamics as well as high quality remote sensing data.
6 Gintamo, T. T.; Mengistu, H.; Kanyerere, T. 2021. GIS-based modelling of climate variability impacts on groundwater quality: Cape Flats Aquifer, Cape Town, South Africa. Groundwater for Sustainable Development, 15:100663. [doi: https://doi.org/10.1016/j.gsd.2021.100663]
Climate variability ; Geographical information systems ; Hydrological modelling ; Groundwater recharge ; Water quality ; Parameters ; Aquifers ; Climate change ; Vulnerability ; Water supply ; Water balance ; Runoff ; Precipitation ; Temperature ; Salinity ; Evapotranspiration / South Africa / Cape Town / Cape Flats Aquifer
(Location: IWMI HQ Call no: e-copy only Record No: H050854)
https://www.sciencedirect.com/science/article/pii/S2352801X2100120X/pdfft?md5=5d9fdcf2defc38064e3037e32fff2ce3&pid=1-s2.0-S2352801X2100120X-main.pdf
https://vlibrary.iwmi.org/pdf/H050854.pdf
https://vlibrary.iwmi.org/pdf/H050854.pdf
(14.80 MB) (14.8 MB)
The need to improve groundwater security remains critical, especially in urban areas where demand for groundwater as an alternative source of water supply is increasing following unprecedented population growth. Climate change continues to threaten groundwater resources in such areas. This study assessed and analysed data from a variety of sources that required holistic analytical tools to demonstrate the impacts of climate change on groundwater quality at the local level. We evaluated how climate conditions affect groundwater quality using a hydrological model (WaterWorld model) in a GIS context. The Cape Flats Aquifer in the city of Cape Town in South Africa was chosen as a case study. The WaterWorld model was used to calculate hydrologic scenarios based on climate change factors and groundwater quality parameters for the period 1950–2000. Mean annual precipitation and temperature were simulated using the multi-model mean and Representative Concentration Pathway 8.5 for the years 2041–2060. Simulation results showed that annual precipitation will increase until 2041 and then decrease until 2060. A significant temperature increase of 1.9 °C–2.3 °C was predicted. Water balance simulations showed a decrease of about 8.6% per year under the future dry climate. ArcGIS 10.3 was used to combine geospatial data and develop a groundwater vulnerability map. Modelling analysis based on GIS showed that the southern and central suburbs of the study area are more susceptible to groundwater contamination and have high surface runoff and higher average temperatures. The groundwater vulnerability index and electrical conductivity concentrations showed a strong positive correlation when the model was validated using linear regression analysis (R2 = 0.99, P < 0.05). In this article, we recommend the use of the WaterWorld model in a GIS environment to simulate hydrologic scenarios on climate change and groundwater quality parameters to provide practical and feasible insights for actions to improve groundwater management.
7 Ougahi, J. H.; Cutler, M. E. J.; Cook, S. J. 2021. Modelling climate change impact on water resources of the Upper Indus Basin. Journal of Water and Climate Change, 23p. (Online first) [doi: https://doi.org/10.2166/wcc.2021.233]
Water resources ; River basins ; Climate change ; Hydrological modelling ; Precipitation ; Temperature ; Water balance ; Evapotranspiration ; Water yield ; Forecasting ; Soil moisture ; Parameters ; Calibration ; Uncertainty / Pakistan / Upper Indus Basin / Upper Jhelum River Basin / Kabul River Basin / Himalaya / Hindu Kush / Karakoram / Tarbela / Mangla / Nowshera
(Location: IWMI HQ Call no: e-copy only Record No: H050862)
https://iwaponline.com/jwcc/article-pdf/doi/10.2166/wcc.2021.233/980841/jwc2021233.pdf
https://vlibrary.iwmi.org/pdf/H050862.pdf
https://vlibrary.iwmi.org/pdf/H050862.pdf
(1.47 MB) (1.47 MB)
Climate change has implications for water resources by increasing temperature, shifting precipitation patterns and altering the timing of snowfall and glacier melt, leading to shifts in the seasonality of river flows. Here, the Soil & Water Assessment Tool was run using downscaled precipitation and temperature projections from five global climate models (GCMs) and their multi-model mean to estimate the potential impact of climate change on water balance components in sub-basins of the Upper Indus Basin (UIB) under two emission (RCP4.5 and RCP8.5) and future (2020–2050 and 2070–2100) scenarios. Warming of above 6 °C relative to baseline (1974–2004) is projected for the UIB by the end of the century (2070–2100), but the spread of annual precipitation projections among GCMs is large (+16 to -28%), and even larger for seasonal precipitation (+91 to -48%). Compared to the baseline, an increase in summer precipitation (RCP8.5: +36.7%) and a decrease in winter precipitation were projected (RCP8.5: -16.9%), with an increase in average annual water yield from the nival–glacial regime and river flow peaking 1 month earlier. We conclude that predicted warming during winter and spring could substantially affect the seasonal river flows, with important implications for water supplies.
8 Omonge, P.; Feigl, M.; Olang, L.; Schulz, K.; Herrnegger, M. 2022. Evaluation of satellite precipitation products for water allocation studies in the Sio-Malaba-Malakisi River Basin of East Africa. Journal of Hydrology: Regional Studies, 39:100983. [doi: https://doi.org/10.1016/j.ejrh.2021.100983]
Water allocation ; Precipitation ; Satellite observation ; River basins ; Hydrological modelling ; Datasets ; Rainfall patterns ; Estimation ; Runoff ; Water balance ; Rain gauges / East Africa / Kenya / Uganda / Sio-Malaba-Malakisi River Basin / Lake Victoria
(Location: IWMI HQ Call no: e-copy only Record No: H050869)
https://www.sciencedirect.com/science/article/pii/S2214581821002123/pdfft?md5=0175f7656f4a85555f7f4120eaccf665&pid=1-s2.0-S2214581821002123-main.pdf
https://vlibrary.iwmi.org/pdf/H050869.pdf
https://vlibrary.iwmi.org/pdf/H050869.pdf
(12.90 MB) (12.9 MB)
Study region: Sio Malaba Malakisi river basin, East Africa.
Study focus: Poor rain-gauge density is a limitation to comprehensive hydrological studies in Sub-Saharan Africa. Consequently, Satellite precipitation products (SPPs) provide an alternative source of data for possible use in hydrological modeling. However, there is need to test their reliabilities across varied hydro-climatic and physiographic conditions to understand their applicability. Using two approaches, we evaluated the performance of six SPPs against gauge observations for possible water allocation studies in the SMMRB: (i) a point to pixel comparison using different statistical measures; (ii) hydrological evaluation of simulated discharge using the Continuous SEmi-distributed Runoff (COSERO) model approach.
New hydrological insights for the region: Our results indicate that CHIRPSv2 product performed best followed by MSWEPv2.2 as they suitably detected seasonal and annual rainfall amounts throughout the basin. However, at lower altitudes, most of the products overestimated rainfall as indicated by the performance measures. In some parts of the basin, the COSERO output signify an underperformance by PERSIANN-CDR and a good performance by GPM-3IMERG6. This could be attributed to differences in temporal dynamics of the products. In overall, seasonal trends captured by the SPPs can be used to support catchment management efforts in data scarce regions.
Study focus: Poor rain-gauge density is a limitation to comprehensive hydrological studies in Sub-Saharan Africa. Consequently, Satellite precipitation products (SPPs) provide an alternative source of data for possible use in hydrological modeling. However, there is need to test their reliabilities across varied hydro-climatic and physiographic conditions to understand their applicability. Using two approaches, we evaluated the performance of six SPPs against gauge observations for possible water allocation studies in the SMMRB: (i) a point to pixel comparison using different statistical measures; (ii) hydrological evaluation of simulated discharge using the Continuous SEmi-distributed Runoff (COSERO) model approach.
New hydrological insights for the region: Our results indicate that CHIRPSv2 product performed best followed by MSWEPv2.2 as they suitably detected seasonal and annual rainfall amounts throughout the basin. However, at lower altitudes, most of the products overestimated rainfall as indicated by the performance measures. In some parts of the basin, the COSERO output signify an underperformance by PERSIANN-CDR and a good performance by GPM-3IMERG6. This could be attributed to differences in temporal dynamics of the products. In overall, seasonal trends captured by the SPPs can be used to support catchment management efforts in data scarce regions.
9 Idrissou, M.; Diekkruger, B.; Tischbein, B.; Op de Hipt, F.; Naschen, K.; Pomeon, T.; Yira, Y.; Ibrahim, B. 2022. Modeling the impact of climate and land use/land cover change on water availability in an inland valley catchment in Burkina Faso. Hydrology, 9(1):12. (Special issue: Integrated Effect of Climate and Land Use on Hydrology and Soil Erosion) [doi: https://doi.org/10.3390/hydrology9010012]
Climate change ; Land use change ; Land cover change ; Water availability ; Catchment areas ; Hydrological modelling ; Forecasting ; Precipitation ; Climate variability ; Evapotranspiration ; Water balance ; Farmland ; Vegetation ; Impact assessment ; Uncertainty / West Africa / Burkina Faso / Bankandi-Loffing Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H050874)
(4.07 MB) (4.07 MB)
Water scarcity for smallholder farming in West Africa has led to the shift of cultivation from uplands to inland valleys. This study investigates the impacts of climate and land use/land cover (LULC) change on water resources in an intensively instrumented inland valley catchment in Southwestern Burkina Faso. An ensemble of five regional climate models (RCMs) and two climate scenarios (RCP 4.5 and RCP 8.5) was utilized to drive a physically-based hydrological model WaSiM after calibration and validation. The impact of climate change was quantified by comparing the projected period (2021–2050) and a reference period (1971–2000). The result showed a large uncertainty in the future change of runoff between the RCMs. Three models projected an increase in the total runoff from +12% to +95%, whereas two models predicted a decrease from -44% to -24%. Surface runoff was projected to show the highest relative change compared to the other runoff components. The projected LULC 2019, 2025, and 2030 were estimated based on historical LULC change (1990–2013) using the Land Change Modeler (LCM). A gradual conversion of savanna to cropland was shown, with annual rates rom 1 to 3.3%. WaSiM was used to simulate a gradual increase in runoff with time caused by this land use change. The combined climate and land use change was estimated using LULC-2013 in the reference period and LULC-2030 as future land use. The results suggest that land use change exacerbates the increase in total runoff. The increase in runoff was found to be +158% compared to the reference period but only +52% without land use change impacts. This stresses the fact that land use change impact is not negligible in this area, and climate change impact assessments without land use change analysis might be misleading. The results of this study can be used as input to water management models in order to derive strategies to cope with present and future water scarcities for smallholder farming in the investigated area.
10 Trnka, M.; Vizina, A.; Hanel, M.; Balek, J.; Fischer, M.; Hlavinka, P.; Semeradova, D.; Stepanek, P.; Zahradnicek, P.; Skalak, P.; Eitzinger, J.; Dubrovsky, M.; Maca, P.; Belinova, M.; Zeman, E.; Brazdil, R. 2022. Increasing available water capacity as a factor for increasing drought resilience or potential conflict over water resources under present and future climate conditions. Agricultural Water Management, 264:107460. (Online first) [doi: https://doi.org/10.1016/j.agwat.2022.107460]
Water availability ; Water resources ; Drought ; Resilience ; Climate change ; Water balance ; Soil water retention ; Soil moisture ; Water holding capacity ; Precipitation ; Trends ; River basins ; Hydrological modelling ; Land use / Czechia
(Location: IWMI HQ Call no: e-copy only Record No: H050925)
(16.00 MB)
The close relationship between the onset and severity of agricultural and hydrological drought is considered self-evident, yet relatively few studies have addressed the effects of applying agricultural drought adaptation to hydrological drought characteristics. The present study applies a model cascade capable of simultaneously considering the interactions between agricultural and hydrological droughts. The study area covers all river basins in the Czech Republic and includes the periods of 1956–2015 (baseline) and 2021–2080 (future). The model cascade was shown to explain 91% of the variability in the seasonal and annual accumulated runoff and allows for the analysis of increasing/maintaining/decreasing available water capacity (AWC) across the 133 defined basins with a total area of c. 78,000 km2. The study reports that the probability and extent of agricultural drought increased over the entire period with higher AWC scenario showing slower pace of such increase especially from April to June. The trends in the extent or severity of hydrological droughts were of low magnitude. The future climate has been projected through the use of ensembles of five global (CMIP5) and five regional (EURO-CORDEX) climate models. The results showed a significant increase in the duration of agricultural drought stress and in the area affected throughout the year, particularly in July–September. The hydrological drought response showed a marked difference between areas with a negative and positive climatic water balance, i.e., areas where long-term reference evapotranspiration exceeds long-term precipitation (negative climatic water balance) and where it does not (positive climatic water balance). The overall results indicate that increasing soil AWC would decrease the frequency and likely also impact of future agricultural droughts, especially during spring. This result would be especially true if the wetter winters predicted by some of the models materialized. Hydrological droughts at the country level are estimated to become more pronounced with increasing AWC, particularly in catchments with a negative climatic water balance.
11 Veettil, A. V.; Mishra, A. K.; Green, T. R. 2022. Explaining water security indicators using hydrologic and agricultural systems models. Journal of Hydrology, 607:127463. (Online first) [doi: https://doi.org/10.1016/j.jhydrol.2022.127463]
Water security ; Indicators ; Hydrological modelling ; Agriculture ; Water footprint ; Water demand ; Water scarcity ; Water stress ; Water quality ; Water storage ; Water availability ; Freshwater ; Watersheds ; Food production ; Fertilizer application ; Biofuels ; Crop management ; Irrigated farming ; Precipitation ; Spatial distribution / USA / Colorado / Big Dry Creek Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H050926)
(3.41 MB)
Water security plays an important role in socio-economic development, ecosystem management, and environmental sustainability. Over the last four decades, water security assessment has attracted much political and economic attention. An improved understanding of the relationships between water demand and supply is needed to mitigate the impacts of diminishing water resources. This study provides an overview of water security assessment by focusing on the various water security indicators and the concept of water footprint (blue, green, and grey water). The water security indicators based on the water footprint concept is currently receiving more attention because it accounts for the return flow from the total water withdrawn from a watershed. We also investigate the application of different physically-based hydrological models, such as Soil and Water Assessment Tool (SWAT) and Variable Infiltration Capacity (VIC), on water security assessment at a regional to continental scale. However, hydrological/agricultural system models cannot quantify evapotranspiration from irrigation and rainwater separately. Therefore, independent quantification of blue and green water footprint from an irrigated field is challenging. For illustration purposes, we apply the fully distributed Agricultural Ecosystems Services (AgES) model in the Big Dry Creek Watershed (BDCW), an intensively managed and irrigated watershed located in semiarid Colorado. The results indicate that the blue water footprint is higher than the green water footprint in the watershed. In addition, the spatial distribution of grey water footprint is highly correlated with the amount of fertilizer application. The variation of grey water footprint among the irrigated fields is higher than blue and green water footprints. We conclude that applying a physically distributed model can provide useful insight into the impact of climate and anthropogenic activities on water security at different scales.
12 Mohammed, I. N.; Bolten, J. D.; Souter, N. J.; Shaad, K.; Vollmer, D. 2022. Diagnosing challenges and setting priorities for sustainable water resource management under climate change. Scientific Reports, 12:796. [doi: https://doi.org/10.1038/s41598-022-04766-2]
Water resources ; Water management ; Sustainability ; Climate change ; River basins ; Water governance ; Transboundary waters ; Conflicts ; Hydropower ; Dams ; Infrastructure ; Stakeholders ; Decision making ; Indicators ; Dry season ; Wet season ; Ecosystem services ; Freshwater ; Precipitation ; Flooding ; Hydrological modelling / Lao People's Democratic Republic / Vietnam / Cambodia / Lower Mekong River Basin / Se Kong River / Sre Pok River / Se San River
(Location: IWMI HQ Call no: e-copy only Record No: H050930)
(1.72 MB) (1.72 MB)
Managing transboundary river basins requires balancing tradeoffs of sustainable water use and coping with climate uncertainty. We demonstrate an integrated approach to exploring these issues through the lens of a social-ecological system, combining remote and in-situ earth observations, hydrologic and climate models, and social surveys. Specifically, we examine how climate change and dam development could impact the Se Kong, Se San and Sre Pok rivers in the Mekong region. We find that climate change will lead to increased precipitation, necessitating a shift in dam operations, from maintaining low flows to reducing flood hazards. We also find that existing water governance systems in Laos, Vietnam, and Cambodia are ill-prepared to address the problem. We conclude that the solution space for addressing these complex issues will be highly constrained unless major deficiencies in transboundary water governance, strategic planning, financial capacity, information sharing, and law enforcement are remedied in the next decades.
13 Akhtar, F.; Awan, Usman Khalid; Borgemeister, C.; Tischbein, B. 2021. Coupling remote sensing and hydrological model for evaluating the impacts of climate change on streamflow in data-scarce environment. Sustainability, 13(24):14025. [doi: https://doi.org/10.3390/su132414025]
Climate change ; Remote sensing ; Hydrological modelling ; Forecasting ; River basins ; Stream flow ; Water resources ; Precipitation ; Land use ; Land cover ; Soil types ; Calibration / Afghanistan / Kabul River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050783)
(6.38 MB) (6.38 MB)
The Kabul River Basin (KRB) in Afghanistan is densely inhabited and heterogenic. The basin’s water resources are limited, and climate change is anticipated to worsen this problem. Unfortunately, there is a scarcity of data to measure the impacts of climate change on the KRB’s current water resources. The objective of the current study is to introduce a methodology that couples remote sensing and the Soil and Water Assessment Tool (SWAT) for simulating the impact of climate change on the existing water resources of the KRB. Most of the biophysical parameters required for the SWAT model were derived from remote sensing-based algorithms. The SUFI-2 technique was used for calibrating and validating the SWAT model with streamflow data. The stream-gauge stations for monitoring the streamflow are not only sparse, but the streamflow data are also scarce and limited. Therefore, we selected only the stations that are properly being monitored. During the calibration period, the coefficient of determination (R2) and Nash–Sutcliffe Efficiency (NSE) were 0.75–0.86 and 0.62–0.81, respectively. During the validation period (2011–2013), the NSE and R2 values were 0.52–0.73 and 0.65–0.86, respectively. The validated SWAT model was then used to evaluate the potential impacts of climate change on streamflow. Regional Climate Model (RegCM4-4) was used to extract the data for the climate change scenarios (RCP 4.5 and 8.5) from the CORDEX domain. The results show that streamflow in most tributaries of the KRB would decrease by a maximum of 5% and 8.5% under the RCP 4.5 and 8.5 scenarios, respectively. However, streamflow for the Nawabad tributary would increase by 2.4% and 3.3% under the RCP 4.5 and 8.5 scenarios, respectively. To mitigate the impact of climate change on reduced/increased surface water availability, the SWAT model, when combined with remote sensing data, can be an effective tool to support the sustainable management and strategic planning of water resources. Furthermore, the methodological approach used in this study can be applied in any of the data-scarce regions around the world.
14 Richards, N.; Gutierrez-Arellano, C. 2022. Effects of community-based water management decisions at catchment scale, an interdisciplinary approach: the case of the Great Ruaha River Catchment, Tanzania. Water Practice and Technology, 17(2):598-611. [doi: https://doi.org/10.2166/wpt.2022.010]
Integrated water resources management ; Decision making ; Community organizations ; Natural resources management ; Catchment areas ; Water insecurity ; Water user associations ; Water balance ; Irrigation ; Runoff ; Water institutions ; Participatory management ; Farmland ; Dry season ; Wet season ; Lowland ; Deforestation ; Hydrological modelling ; Evapotranspiration / United Republic of Tanzania / Great Ruaha River Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H050947)
https://iwaponline.com/wpt/article-pdf/17/2/598/1012169/wpt0170598.pdf
https://vlibrary.iwmi.org/pdf/H050947.pdf
https://vlibrary.iwmi.org/pdf/H050947.pdf
(0.62 MB) (632 KB)
Water User Associations are community-based institutions that cover segments of rivers and are responsible for water management decisions. These are the result of institutional blueprints designed by the international community, widely adopted around the world. However, the implementation gaps between these generic institutional designs and the working on the ground are vast and require site-specific information to support water management decisions at the local scale. We used a hydrological modelling approach to assess how community-based decisions can maximize their outcomes and improve overall availability of water resources in the Great Ruaha River Catchment in Tanzania, a catchment that is under severe drought pressures and is of the utmost ecological, social, and political relevance at the national scale. We provide information to support decisions on when and where to focus conservation and management strategies by identifying the seasonal and spatial variability of water availability in the catchment. Our methods have the potential to be used in other catchments around the world. This study shows the importance of assessing the hydrological processes affecting the geographies of community-based institutions to identify priority areas of action.
15 Dembele, Moctar; Vrac, M.; Ceperley, N.; Zwart, Sander J.; Larsen, J.; Dadson, S. J.; Mariethoz, G.; Schaefli, B. 2022. Contrasting changes in hydrological processes of the Volta River Basin under global warming. Hydrology and Earth System Sciences, 26(5):1481-1506. [doi: https://doi.org/10.5194/hess-26-1481-2022]
River basins ; Hydrological cycle ; Global warming ; Hydrological modelling ; Climate change ; Forecasting ; Water availability ; Hydroclimate ; Climatic zones ; Spatial variation ; Datasets / West Africa / Volta River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H051026)
https://hess.copernicus.org/articles/26/1481/2022/hess-26-1481-2022.pdf
https://vlibrary.iwmi.org/pdf/H051026.pdf
https://vlibrary.iwmi.org/pdf/H051026.pdf
(4.33 MB) (4.33 MB)
A comprehensive evaluation of the impacts of climate change on water resources of the West Africa Volta River basin is conducted in this study, as the region is expected to be hardest hit by global warming. A large ensemble of 12 general circulation models (GCMs) from the fifth Coupled Model Intercomparison Project (CMIP5) that are dynamically downscaled by five regional climate models (RCMs) from the Coordinated Regional-climate Downscaling Experiment (CORDEX)-Africa is used. In total, 43 RCM–GCM combinations are considered under three representative concentration pathways (RCP2.6, RCP4.5, and RCP8.5). The reliability of each of the climate datasets is first evaluated with satellite and reanalysis reference datasets. Subsequently, the Rank Resampling for Distributions and Dependences (R2D2) multivariate bias correction method is applied to the climate datasets. The bias-corrected climate projections are then used as input to the mesoscale Hydrologic Model (mHM) for hydrological projections over the 21st century (1991–2100).
Results reveal contrasting dynamics in the seasonality of rainfall, depending on the selected greenhouse gas emission scenarios and the future projection periods. Although air temperature and potential evaporation increase under all RCPs, an increase in the magnitude of all hydrological variables (actual evaporation, total runoff, groundwater recharge, soil moisture, and terrestrial water storage) is only projected under RCP8.5. High- and low-flow analysis suggests an increased flood risk under RCP8.5, particularly in the Black Volta, while hydrological droughts would be recurrent under RCP2.6 and RCP4.5, particularly in the White Volta. The evolutions of streamflow indicate a future delay in the date of occurrence of low flows up to 11 d under RCP8.5, while high flows could occur 6 d earlier (RCP2.6) or 5 d later (RCP8.5), as compared to the historical period.
Disparities are observed in the spatial patterns of hydroclimatic variables across climatic zones, with higher warming in the Sahelian zone. Therefore, climate change would have severe implications for future water availability with concerns for rain-fed agriculture, thereby weakening the water– energy–food security nexus and amplifying the vulnerability of the local population. The variability between climate models highlights uncertainties in the projections and indicates a need to better represent complex climate features in regional models. These findings could serve as a guideline for both the scientific community to improve climate change projections and for decision-makers to elaborate adaptation and mitigation strategies to cope with the consequences of climate change and strengthen regional socioeconomic development.
Results reveal contrasting dynamics in the seasonality of rainfall, depending on the selected greenhouse gas emission scenarios and the future projection periods. Although air temperature and potential evaporation increase under all RCPs, an increase in the magnitude of all hydrological variables (actual evaporation, total runoff, groundwater recharge, soil moisture, and terrestrial water storage) is only projected under RCP8.5. High- and low-flow analysis suggests an increased flood risk under RCP8.5, particularly in the Black Volta, while hydrological droughts would be recurrent under RCP2.6 and RCP4.5, particularly in the White Volta. The evolutions of streamflow indicate a future delay in the date of occurrence of low flows up to 11 d under RCP8.5, while high flows could occur 6 d earlier (RCP2.6) or 5 d later (RCP8.5), as compared to the historical period.
Disparities are observed in the spatial patterns of hydroclimatic variables across climatic zones, with higher warming in the Sahelian zone. Therefore, climate change would have severe implications for future water availability with concerns for rain-fed agriculture, thereby weakening the water– energy–food security nexus and amplifying the vulnerability of the local population. The variability between climate models highlights uncertainties in the projections and indicates a need to better represent complex climate features in regional models. These findings could serve as a guideline for both the scientific community to improve climate change projections and for decision-makers to elaborate adaptation and mitigation strategies to cope with the consequences of climate change and strengthen regional socioeconomic development.
16 Ashraf, S.; Ali, M.; Shrestha, S.; Hafeez, M. A.; Moiz, A.; Sheikh, Z. A. 2022. Impacts of climate and land-use change on groundwater recharge in the semi-arid Lower Ravi River Basin, Pakistan. Groundwater for Sustainable Development, 17:100743. (Online first) [doi: https://doi.org/10.1016/j.gsd.2022.100743]
Groundwater recharge ; Climate change ; Land use change ; River basins ; Semiarid zones ; Forecasting ; Hydrological modelling ; Water balance ; Precipitation ; Farmland / Pakistan / Ravi River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050999)
(6.98 MB)
Climate and land-use change significantly impact the hydrological cycle and water resources. Groundwater recharge of the Lower Ravi River Basin (LRRB), Pakistan, using the Soil and Water Assessment Tool (SWAT) hydrological model was studied. Three General Circulation Models (GCMs) under two Representative Concentration Pathways (RCP 4.5 and 8.5) were used to project future rainfall and temperature. Present climate and land-use were used to develop the SWAT model. Future land-use was generated by using land-use change predictor model, CA-Markov from present maps. Groundwater recharge fluctuated with changing climate and land-use with an increase of annual temperature by 2.1 °C and 3.7 °C for RCP 4.5 and 8.5 respectively, by 2050. The annual mean precipitation increased by 2.45% and 4.47% for both scenarios resulting in an 8% rise in recharge along with a seasonal shift. Future land-use change reduced recharge up to 38%. The combined impacts of climate and land-use change reduced groundwater recharge by 15%.
17 Wolfand, J. M.; Taniguchi-Quan, K. T.; Abdi, R.; Gallo, E.; Irving, K.; Philippus, D.; Rogers, J. B.; Stein, E. D.; Hogue, T. S. 2022. Balancing water reuse and ecological support goals in an effluent dominated river. Journal of Hydrology X, 15:100124. [doi: https://doi.org/10.1016/j.hydroa.2022.100124]
Rivers ; Water reuse ; Effluents ; Ecological factors ; Wastewater treatment ; Environmental flows ; Water management ; Watersheds ; Freshwater ; Water quality ; Hydrological modelling ; Dry season ; Wet season / USA / California / Los Angeles River
(Location: IWMI HQ Call no: e-copy only Record No: H051005)
https://www.sciencedirect.com/science/article/pii/S2589915522000062/pdfft?md5=5c47f02837739b38622f7930cf01aa30&pid=1-s2.0-S2589915522000062-main.pdf
https://vlibrary.iwmi.org/pdf/H051005.pdf
https://vlibrary.iwmi.org/pdf/H051005.pdf
(5.56 MB) (5.56 MB)
Flows in urban rivers are increasingly managed to support water supply needs while also protecting and/or restoring instream ecological functions, goals that are often in opposition to each other. Effluent-dominated rivers (i.e., rivers that consist primarily of discharged treated wastewater) pose a particular challenge because changes in effluent discharge may impact river ecology. A functional flows approach, in which metrics from the annual hydrograph correspond to ecological processes, was applied to understand the hydro-ecological implications of wastewater reuse in the Los Angeles River watershed (Los Angeles County, California, USA). The Los Angeles River, like many urban rivers, is dominated by effluent, particularly during dry weather. An hourly hydrologic model was created, calibrated, and validated in EPA SWMM for the Los Angeles River watershed to investigate how increases in wastewater reuse (i.e., decreases in discharge to the river) may impact river flows and subsequently ecology and recreation in the river. Current flows are shown to support freshwater marsh, riparian habitat, fish migration, and wading shorebird habitat, in addition to recreational kayaking. Functional flow metrics were assessed under future management scenarios including reducing discharge to increase recycling at three wastewater treatment plants within the watershed. Both wet-season and dry-season baseflows were most sensitive to increasing wastewater reuse, with an average decrease of 51–56% (0.93 cms) from current baseflows. Sensitivity curves that relate potential changes in wastewater discharge to changes in functional flows show that a 4% decrease in current wastewater discharge may negatively impact habitat for indicator species during the dry season. More opportunity exists for wastewater reuse during the wet season, when current wastewater discharge may be reduced by 24% with minimal impacts to ecology and recreation. The developed approach has the potential to inform similar tradeoff decisions in other urban rivers where flows are dominated by wastewater or stormdrain discharge.
18 Marques, A. C.; Veras, C. E.; Rodriguez, D. A. 2022. Assessment of water policies contributions for sustainable water resources management under climate change scenarios. Journal of Hydrology, 608:127690. [doi: https://doi.org/10.1016/j.jhydrol.2022.127690]
Water policies ; Assessment ; Water resources ; Water management ; Sustainability ; Climate change ; Water availability ; Water security ; Water demand ; Water supply ; River basins ; Stream flow ; Forecasting ; Precipitation ; Vulnerability ; Decision making ; Public policies ; Hydrological modelling / Brazil / Paraiba do Sul River Basin / Guandu River
(Location: IWMI HQ Call no: e-copy only Record No: H051006)
(4.90 MB)
Economic development alongside unsustained population growth are among the leading factors of hydrological depletion. Facing climate change impacts, long-term policy planning via scenario analysis is an essential tool to ensure water security. This investigation utilized an approach based on numerical model experiments and sustainability indexes to assess the impact of public policies for water resources management over a long-term horizon. Streamflow projections (2011–2099) from the hydrological model MHD-INPE (Distributed Hydrological Model – National Institute for Space Research) were evaluated as means to investigate water supply scenarios. Monthly flows were accounted into 30-year moving average intervals. Sustainability Indexes were then calculated to evaluate the performance of a water system as IPCC’s Specific Warming Levels were reached. In this study, the contribution of public policies for water resources sustainability under climate change scenarios in the Paraíba do Sul river basin, which supports the water supply of the two major Brazilian metropolitan areas, were analyzed. Results indicated that the system will operate with more stress facing climate change impacts. Finally, the assessment of water availability scenarios is concluded to benefit decision-makers in incorporating adaptation measures, identifying uncertainties, and foreseeing potential effects of climate change.
19 Mensah, J. K.; Ofosu, E. A.; Yidana, S. M.; Akpoti, Komlavi; Kabo-bah, A. T. 2022. Integrated modeling of hydrological processes and groundwater recharge based on land use land cover, and climate changes: a systematic review. Environmental Advances, 8:100224. [doi: https://doi.org/10.1016/j.envadv.2022.100224]
Hydrological modelling ; Groundwater recharge ; Land use change ; Land cover change ; Climate change
(Location: IWMI HQ Call no: e-copy only Record No: H051080)
https://www.sciencedirect.com/science/article/pii/S266676572200059X/pdfft?md5=1e1fa4273fd95cdf7b681f7387c5922e&pid=1-s2.0-S266676572200059X-main.pdf
https://vlibrary.iwmi.org/pdf/H051080.pdf
https://vlibrary.iwmi.org/pdf/H051080.pdf
(6.22 MB) (6.22 MB)
Groundwater is the main available freshwater resource and therefore its use, management and sustainability are closely related to the Sustainable Development Goals (SDGs). However, Land Use Land Cover (LULC) and climate change are among the factors impacting groundwater recharge. The use of land-use and climate data in conjunction with hydrological models are valuable tools for assessing these impacts on river basins. This systematic review aimed at assessing the integrated modeling approach for evaluating hydrological processes and groundwater recharge based on LULC and climate change. The analysis is based on 200 peer-reviewed articles indexed in Scopus, and the Web of Science. Continuous research and the development of context-specific groundwater recharge models are essential to increase the long-term viability of water resources in any basin. The long-term impacts of natural and anthropogenic drivers on river basin interactions require integrating knowledge and modeling capabilities across biophysical responses, environmental problems, policies, economics, social, and data.
20 Ijaz, M. A.; Ashraf, M.; Hamid, S.; Niaz, Y.; Waqas, M. M.; Tariq, M. A. U. R.; Saifullah, M.; Bhatti, Muhammad Tousif; Tahir, A. A.; Ikram, K.; Shafeeque, M.; Ng, A. W. M. 2022. Prediction of sediment yield in a data-scarce river catchment at the sub-basin scale using gridded precipitation datasets. Water, 14(9):1480. (Special issue: Innovate Approaches to Sustainable Water Resource Management under Population Growth, Lifestyle Improvements, and Climate Change) [doi: https://doi.org/10.3390/w14091480]
Sediment yield ; Forecasting ; River basins ; Catchment areas ; Precipitation ; Datasets ; Hydrological modelling ; Watershed management ; Dams ; Runoff ; Sediment load ; Soil erosion ; Soil types ; Land use ; Rain ; Semiarid zones ; Spatial distribution / Pakistan / Gomal River Catchment / Kot Murtaza Barrage / Gomal Zam Dam
(Location: IWMI HQ Call no: e-copy only Record No: H051151)
https://www.mdpi.com/2073-4441/14/9/1480/pdf?version=1652347380
https://vlibrary.iwmi.org/pdf/H051151.pdf
https://vlibrary.iwmi.org/pdf/H051151.pdf
(2.15 MB) (2.15 MB)
Water-related soil erosion is a major environmental concern for catchments with barren topography in arid and semi-arid regions. With the growing interest in irrigation infrastructure development in arid regions, the current study investigates the runoff and sediment yield for the Gomal River catchment, Pakistan. Data from a precipitation gauge and gridded products (i.e., GPCC, CFSR, and TRMM) were used as input for the SWAT model to simulate runoff and sediment yield. TRMM shows a good agreement with the data of the precipitation gauge (˜1%) during the study period, i.e., 2004–2009. However, model simulations show that the GPCC data predicts runoff better than the other gridded precipitation datasets. Similarly, sediment yield predicted with the GPCC precipitation data was in good agreement with the computed one at the gauging site (only 3% overestimated) for the study period. Moreover, GPCC overestimated the sediment yield during some years despite the underestimation of flows from the catchment. The relationship of sediment yields predicted at the sub-basin level using the gauge and GPCC precipitation datasets revealed a good correlation (R2 = 0.65) and helped identify locations for precipitation gauging sites in the catchment area. The results at the sub-basin level showed that the sub-basin located downstream of the dam site contributes three (3) times more sediment yield (i.e., 4.1%) at the barrage than its corresponding area. The findings of the study show the potential usefulness of the GPCC precipitation data for the computation of sediment yield and its spatial distribution over data-scarce catchments. The computations of sediment yield at a spatial scale provide valuable information for deciding watershed management strategies at the sub-basin level.
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