Simulation of the impact of climate change on runoff and drought in an arid and semiarid basin (the Hablehroud, Iran)

Abstract This study evaluates the impact of climate change (CC) on runoff and hydrological drought trends in Hablehroud river basin central Iran. We used a daily time series minimum temperature (Tmin), maximum (Tmax), precipitation (PCP) for baseline period (1982–2005) analysis. For future projections, we output 23 CMIP5 GCMs two scenarios, RCP 4.5 8.5; then, PCP, Tmin, Tmax were projected (2025–2048). The weighed based K-nearest neighbors algorithm. results indicated rising all months increasing PCP most throughout basin's areas period. highest increase Tmin south under 8.5 scenario, respectively, was 1.87 °C 1.80 °C. Furthermore, reduction 54.88% August scenario. flow simulated by IHACRES rainfall-runoff model. annual scenarios declined 11.44% 13.13%, respectively. had downward trend at period; however, it will have scenario an upward also analyzed calculating streamflow index different scales. Overall, face short-term medium-term