Abstract:
Abstract: It is anticipated that climate change will impact sediment yield in watersheds. The purpose
of this study was to investigate the impacts of climate change on sediment yield from the Logiya
watershed in the lower Awash Basin, Ethiopia. Here, we used the coordinated regional climate
downscaling experiment (CORDEX)-Africa data outputs of Hadley Global Environment Model
2-Earth System (HadGEM2-ES) under representative concentration pathway (RCP) scenarios (RCP4.5
and RCP8.5). Future scenarios of climate change were analyzed in two-time frames: 2020–2049 (2030s)
and 2050–2079 (2060s). Both time frames were analyzed using both RCP scenarios from the baseline
period (1971–2000). A Soil andWater Assessment Tool (SWAT) model was constructed to simulate
the hydrological and the sedimentological responses to climate change. The model performance was
calibrated and validated using the coe cient of determination (R2), Nash–Sutcli e e ciency (NSE),
and percent bias (PBIAS). The results of the calibration and the validation of the sediment yield R2,
NSE, and PBIAS were 0.83, 0.79, and 23.4 and 0.85, 0.76, and 25.0, respectively. The results of
downscaled precipitation, temperature, and estimated evapotranspiration increased in both emission
scenarios. These climate variable increments were expected to result in intensifications in the mean
annual sediment yield of 4.42% and 8.08% for RCP4.5 and 7.19% and 10.79% for RCP8.5 by the 2030s
and the 2060s, respectively.
