Variations of streamflow and sediment yield in the Mosul-Makhool Basin, North of Iraq under climate change: a pre-dam construction study

The Makhool Dam has brought much attention to the Mosul-Makhool Basin (MMB) in Iraq. Dam construction needs comprehensive studies on the impact of climate change on streamflow and sediment yield in watersheds that supply dams; however, there have been no such investigations conducted on the MMB. An ensemble of three Global Circulation Models from Coupled Model Intercomparison Project Phase 6 (CMIP6) with two Shared Socioeconomic Pathways scenarios (SSP2–4.5 and SSP5–8.5) was used to predict the impact of climate change. A distribution mapping downscaling method was utilized to improve the biased climate data. The results indicate that precipitation decreased by 9.5 and 18.7% under SSP2–4.5 and SSP5–8.5 scenarios at the end of the 21st century. The average maximum and minimum temperatures are projected to rise by 2.4 and 1.8 °C in SSP2–4.5 and rise by 3.5 and 2.8 °C in SSP5–8.5 during the study period. The streamflow is expected to decrease by 36.6 and 45.9%, and sediment yield will reduce by 46 and 55% within the same scenarios. Understanding the consequences of climate change helps to face abrupt climate changes to manage dam construction and treat water resources successfully. The results of this research are expected to contribute to improving water management strategies in the study region.