Assessing climate change impacts on surface water availability using the WEAP model: A case study of the Buffalo river catchment, South Africa

Study region: The Buffalo River (BR) catchment, KwaZulu-Natal, South Africa. Study focus: Due to the vast majority of the BR catchment’s water demands not being fully satisfied in recent years, studies investigating potential climate change impacts on the catchment's water supply availability a...

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Main Authors: N. Dlamini, A. Senzanje, T. Mabhaudhi
Format: Article
Language:English
Published: Elsevier 2023-04-01
Series:Journal of Hydrology: Regional Studies
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2214581823000174
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author N. Dlamini
A. Senzanje
T. Mabhaudhi
author_facet N. Dlamini
A. Senzanje
T. Mabhaudhi
author_sort N. Dlamini
collection DOAJ
description Study region: The Buffalo River (BR) catchment, KwaZulu-Natal, South Africa. Study focus: Due to the vast majority of the BR catchment’s water demands not being fully satisfied in recent years, studies investigating potential climate change impacts on the catchment's water supply availability are needed. The study’s objective was to therefore assess climate change-induced surface water availability (SWA) variations in the BR catchment from 2020 to 2100. To achieve this, the hydrologic Water Evaluation and Planning model was forced with the catchment's physical and hydrological data, and projected climate data from an ensemble of GCMs under RCP4.5 and RCP8.5 scenarios from CMIP5. New hydrological insights for the region: The study findings projected increased precipitation, especially in the far future (2070–2100) whereby mean annual precipitation increased by 5 % to 8286 Mm3/annum under the worst-case climate change scenario (RCP8.5). With evapotranspiration and water abstractions averaging 4500 Mm3/annum and 115 Mm3/annum, respectively, surface runoff and SWA increased by 8 % and 10 %, yielding averages of 3265 Mm3/annum and 287 Mm3/annum, respectively. Even with the increased SWA, unmet demands also increased by 113 % towards the end of the 21st century. As the study established that climate change might exacerbate the BR catchment's water supply system's insufficiency to meet growing demands, such findings present an opportunity for the integrated Water-Energy-Food nexus approach to be further utilised for formulating sustainable water management strategies.
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spelling doaj.art-2063157f45994b40b0e7874a57b01d5f2023-03-18T04:41:12ZengElsevierJournal of Hydrology: Regional Studies2214-58182023-04-0146101330Assessing climate change impacts on surface water availability using the WEAP model: A case study of the Buffalo river catchment, South AfricaN. Dlamini0A. Senzanje1T. Mabhaudhi2Bioresources Engineering Programme, University of KwaZulu-Natal, P. Bag X01, Scottsville, Pietermaritzburg, South Africa; Corresponding author.Bioresources Engineering Programme, University of KwaZulu-Natal, P. Bag X01, Scottsville, Pietermaritzburg, South AfricaCentre of Transformative Agricultural and Food Systems, University of KwaZulu-Natal, P. Bag X01, Scottsville, Pietermaritzburg, South Africa; International Water Management Institute (IWMI-SA), South Africa, Pretoria, South AfricaStudy region: The Buffalo River (BR) catchment, KwaZulu-Natal, South Africa. Study focus: Due to the vast majority of the BR catchment’s water demands not being fully satisfied in recent years, studies investigating potential climate change impacts on the catchment's water supply availability are needed. The study’s objective was to therefore assess climate change-induced surface water availability (SWA) variations in the BR catchment from 2020 to 2100. To achieve this, the hydrologic Water Evaluation and Planning model was forced with the catchment's physical and hydrological data, and projected climate data from an ensemble of GCMs under RCP4.5 and RCP8.5 scenarios from CMIP5. New hydrological insights for the region: The study findings projected increased precipitation, especially in the far future (2070–2100) whereby mean annual precipitation increased by 5 % to 8286 Mm3/annum under the worst-case climate change scenario (RCP8.5). With evapotranspiration and water abstractions averaging 4500 Mm3/annum and 115 Mm3/annum, respectively, surface runoff and SWA increased by 8 % and 10 %, yielding averages of 3265 Mm3/annum and 287 Mm3/annum, respectively. Even with the increased SWA, unmet demands also increased by 113 % towards the end of the 21st century. As the study established that climate change might exacerbate the BR catchment's water supply system's insufficiency to meet growing demands, such findings present an opportunity for the integrated Water-Energy-Food nexus approach to be further utilised for formulating sustainable water management strategies.http://www.sciencedirect.com/science/article/pii/S2214581823000174Hydrological modellingWater balanceWater-Energy-Food nexusSustainability
spellingShingle N. Dlamini
A. Senzanje
T. Mabhaudhi
Assessing climate change impacts on surface water availability using the WEAP model: A case study of the Buffalo river catchment, South Africa
Journal of Hydrology: Regional Studies
Hydrological modelling
Water balance
Water-Energy-Food nexus
Sustainability
title Assessing climate change impacts on surface water availability using the WEAP model: A case study of the Buffalo river catchment, South Africa
title_full Assessing climate change impacts on surface water availability using the WEAP model: A case study of the Buffalo river catchment, South Africa
title_fullStr Assessing climate change impacts on surface water availability using the WEAP model: A case study of the Buffalo river catchment, South Africa
title_full_unstemmed Assessing climate change impacts on surface water availability using the WEAP model: A case study of the Buffalo river catchment, South Africa
title_short Assessing climate change impacts on surface water availability using the WEAP model: A case study of the Buffalo river catchment, South Africa
title_sort assessing climate change impacts on surface water availability using the weap model a case study of the buffalo river catchment south africa
topic Hydrological modelling
Water balance
Water-Energy-Food nexus
Sustainability
url http://www.sciencedirect.com/science/article/pii/S2214581823000174
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AT asenzanje assessingclimatechangeimpactsonsurfacewateravailabilityusingtheweapmodelacasestudyofthebuffalorivercatchmentsouthafrica
AT tmabhaudhi assessingclimatechangeimpactsonsurfacewateravailabilityusingtheweapmodelacasestudyofthebuffalorivercatchmentsouthafrica