Modeling of precipitation – runoff for predicting upcoming flow streams in Halilroud basin

Climate change has an impact on discharge in rivers by changing temperature and precipitation. Iran is much more vulnerable to climate change compared to other countries because of the limit water sources and its heterogeneous distribution. Simulation of runoff play an significant role in some environmental and engineering issues. The purpose of this study was to evaluate the impacts of climate change on runoff in Halilroud basin in Kerman using IHACRES model in two time periods (2020-2050, 2070-2100). In this respect, daily data such as rainfall, temperature from 1995 to 2017 were collected.Then, the outputs of CanESM2 model which is a general circulation model (GCM) under two middle emission scenario (RCP4.5) and pessimistic scenario (RCP8.5) using SDSM model were down-scaled. The average temperature in the stations in the present and next periods decreased by 5.6 and 4.6 percent, respectively, and the precipitation in the stations increased by 42.5 percent and in the next period by 40 percent compared to the observation period (1989 - 2017). The predicted values of temperature and precipitation were entered into the IHACRES model by the SDSM climate model and then, the discharge changes were predicted in two periods of time. The average monthly discharge shows an increase in the most warm months of the year in both stations (Kenaruyeh, Cheshmeh ). The results indicated that that the reduction of the temperature and the increase of precipitation in warm months of the year lead to increase in runoff and intensity of flood events in studied area.