Increased water availability and high flows in an ungauged Kenyan catchment: A comprehensive SWAT+ model evaluation for climate change assessment

Study region: The Sand River Basin, Kenya Study focus: This study presents a comprehensive methodology for assessing climate change impacts in ungauged basins. A systematic approach was applied to evaluate model performance and conduct a robust analysis of hydrological responses to climate change. F...

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Bibliographic Details
Main Authors: Pablo Sarmiento, Jingshui Huang, Timo Schaffhauser, Markus Disse
Format: Article
Language:English
Published: Elsevier 2025-08-01
Series:Journal of Hydrology: Regional Studies
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Online Access:http://www.sciencedirect.com/science/article/pii/S2214581825003222
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Summary:Study region: The Sand River Basin, Kenya Study focus: This study presents a comprehensive methodology for assessing climate change impacts in ungauged basins. A systematic approach was applied to evaluate model performance and conduct a robust analysis of hydrological responses to climate change. Five remote sensing evapotranspiration products were evaluated, with the best-performing product selected for further analysis, including climate period robustness and cross-validation with soil moisture. Climate scenarios were constructed based on three pathways (SSP1–2.6, SSP3–7.0, SSP5–8.5) for near (2025–2054) and far future (2070–2099) periods, using five General Circulation Models (GCMs) from the ISIMIP3b dataset linked to CMIP6. New hydrological insights for the region: Results show projected increases in temperature and precipitation across all climate scenarios, becoming more pronounced in the far future under SSP3–7.0 and SSP5–8.5, where early rains are expected in both rainy seasons. The hydrological responses indicate increases in water availability, with strong rises in high flows. These projections are most significant during the far future where the annual average water yield is expected to increase to 179.2 mm (+154.9 %) under SSP3–7.0 and to 185 mm (+163.1 %) under SSP5–8.5. These results highlight the potential implications of climate change on the hydrological components of the basin, providing valuable insights for mitigation and adaptation strategies in the region.
ISSN:2214-5818