Optimal water allocation of the Zayandeh-Roud Reservoir in Iran based on inflow projection under climate change scenarios

Abstract The impact of climate change on water availability has become a significant cause for concern in the Zayandeh-Roud Reservoir Iran and similar reservoirs arid regions. This study investigates supply River Basin. For better management, Soil & Water Assessment Tool (SWAT) was used to develop hydrologic model basin. then calibrated validated two upstream stations using Sequential Uncertainty Fitting (SUFI-2) algorithm SWAT-CUP software. modeled by data derived from five Inter-Sectoral Impact Model Intercomparison Project general circulation models under four Representative Concentration Pathways (RCPs). calibration (1991–2008), Nash–Sutcliffe efficiency (NSE) values 0.75 0.61 at Ghaleshahrokh Eskandari were obtained, respectively. validation (2009–2015), NSE 0.80 0.82, reservoir inflow would probably reduce 40–50% during period 2020–2045 relative base 1981–2006. To evaluate reservoir's future performance, nonlinear optimization minimize deficits. highest annual deficit likely be around 847 MCM. lowest reliability vulnerability occurred extreme RCP8.5 pathway.