Climate Change Impacts on Water Resources in Arid and Semi-Arid Regions: A Case Study in Saudi Arabia

In the coming years, climate change is predicted to impact irrigation water demand considerably, particularly in semi-arid regions. The aim of this research investigate expected adverse impacts on management Saudi Arabia. We focus influence requirements Al Quassim (97,408 ha) region. Different models were used for intermediate emission SSP2-4.5 and high SSP5-8.5 Coupled Model Intercomparison Project Phase 6 (CMIP6) scenarios. FAO-CROPWAT 8.0 model was calculate reference evapotranspiration (ETo) using weather data from 13 stations 1991 2020 both scenarios 2040s, 2060s, 2080s, 2100s. findings indicated that, 2100s, forecast annual average ETo increases 0.35 mm/d (6%) 0.7 (12.0%), respectively. Net requirement (NIWR) growth (GIWR) main crops region assessed current, SSP2-4.5, For SSP5-8.5, GIWR 2100s are increase by 2.7, 6.5, 8.5, 12.4%, respectively, compared current scenario (1584.7 million m3). As a result, there will be higher deficits 2100 under major crops, with 15.1%, 10.7%, 8.3%, 13.9%, 10.7% crop areas wheat, clover, maize, other vegetables, dates, Optimal planning, pattern selection, modern technologies, combined proposed NIWR values, can support resources management. assist managers policymakers better identifying adaptation strategies similar climates.