Impact of Climate Change on Soil Water Availability and Sorghum Water Needs in the Tseriari Watershed, Tekeze Basin, Ethiopia

Climate change poses significant challenges to water resources and crop production, particularly in vulnerable regions such as the Tseriari Watershed in Ethiopia's Tekeze Basin. This study assesses the projected impacts of climate change on soil water availability and sorghum water requirements under SSP2-4.5 and SSP5-8.5 scenarios. From the most suitable CMIP6 climate models for Ethiopia based six models were selected based on recent evaluations are NorESM2-MM, MPI-ESM1-2-HR, ACCESS-CM2, BCC-CSM2-MR, MRI-ESM2-0, and MPI-ESM1-2-LR. The climatic meteorological and hydrological (Cmhyd) model bias correction method was applied. The current and projection climate change impact on soil water availability was estimated using the Soil and water assessment tool (SWAT) model, and sorghum water requirement was determined using CROPWAT Model for baseline period (1980 -2014) and future (2015-2060; 2061-2100) period. Future climate projections indicate increases in both rainfall and temperature by the 2030s and 2050s, with Kiremt rainfall expected to rise by up to 21.73% and mean temperatures by as much as 5.13°C. Soil water content trends showed an initial increase followed by a decline, with projected soil moisture reductions of up to 6.02% during the Kiremt season. Sorghum crop water needs are anticipated to increase by up to 10.28% relative to the baseline. These findings suggest that future climate variability will reduce soil water availability while increasing crop water demands. Therefore, this highlights the need for adaptive water management and crop planning strategies to ensure sustainable agricultural production within the watershed