Climate change impact on the hydrology of Weyb river watershed, bale mountainous area, Ethiopia
Book Chapter
Shawul, AA, Alamirew, T, Melesse, AM et al. (2015). Climate change impact on the hydrology of Weyb river watershed, bale mountainous area, Ethiopia
. 587-613. 10.1007/978-3-319-18787-7_27
Shawul, AA, Alamirew, T, Melesse, AM et al. (2015). Climate change impact on the hydrology of Weyb river watershed, bale mountainous area, Ethiopia
. 587-613. 10.1007/978-3-319-18787-7_27
Identifying local impact of climate change at a watershed level and quantitative estimates of hydrological effects of climate change is crucial for solving potential water resource management problems. The aim of this study was to downscale the global circulation model (GCM) to Weyb watershed for analyzing the impact of climate change on hydrological variability. The SDSM was used to downscale the GCM output and it has accurately replicated the observed series both for A2a and B2a scenarios. SWAT model was calibrated and validated to simulate streamflow. For each future time horizon, the change in mean annual maximum and minimum temperature has indicated a slight increment from the base period both for A2a and B2a scenarios. The projected precipitation revealed the average seasonal precipitation could increase in dry season and decrease in wet season both for A2a and B2a scenarios for the 2020s, 2050s, and 2080s time period. The change in annual streamflow with exception to 2080s shows an increase by 0.83 % and 0.64 % in 2020s and 2050s, respectively, under A2a scenario, and by 5.02 % in 2080s under B2a scenario. Subsurface flow parameters were found to be more sensitive to the streamflow of the watershed. The annual streamflow might be reduced by 1.5 % in 2080s under A2a scenario and could also be reduced by 1.14 % and 0.99 % in 2020s and 2050s, respectively, under B2a scenario. The result has revealed an increase of streamflow on dry season and reduction on the wet and intermediate seasons which has similar pattern with the rainfall. The change in the amount and distribution of rainfall and level of temperature would affect agricultural productivity and water utilizations in the region.
