Investigating the effect of climate change on Increasing thetemperature and potential evapotranspiration using SDSM model in Ahvaz city

Climate change due to increasing the concentration of greenhouse gases (especially CO2) in the atmosphere causes changes in the rainfall regime, runoff rate, wind speed and solar radiation of atmosphere. In the present research, the maximum and minimum temperature parameters were simulated during the base period of 1979-2088 and two future periods of 1979-2070 and 2070-2090 using daily weather data of Ahvaz synoptic station and Hadcm3 model data, under A2 and B2 scenarios The determination of coefficient (R2) and Root Mean Square Error (RMSE) were used to evaluate the ability of the model to simulate climatic parameters. In addition, potential evapotranspiration (ETp) values were calculated and predicted for the aforementioned periods with the Hargreaves-Sammani method. The results showed that the maximum temperature, minimum temperature, and potential evapotranspiration would increase under scenario A2 and B2 at Ahvaz station in the future. The maximum and minimum temperatures for the future period (2020-2049) were 33.47 and 19.042 oC under scenario A2, 33.49 and 19.036 oC under scenario B2 and for the future period (2070-2099) were 34.13 and 19.95 oC under A2 scenario and 33.80 and 19.95 oC under scenario B2. The average of potential evapotranspiration simulated for the future period (2020-2049) was as much as 10.97 and 10.95 mm per day under the scenario A2 and B2 and this amount for the future period (2070-2099) was as much as equal to 11.33 and 11.26 mm per day under scenario A2 and B2. The highest increase for all three periods and under both scenarios was observed in June.