عنوان مقاله [English]
In this research, the effect of climate change on the amount of potential evapotranspiration (ETp) in the southern part of the Aras River basin was estimated and evaluated using the downscaled data of the CanESM2 climate model at the SDSM downscaling model under the RCP scenarios during the period 2021-2050 using the Hargreaves-Samani method and compared with the values of the base period (1985-2005). The ETp estimated by this method for the Aras Basin during the future period based on the down-scaled temperature data of the CanESM2 model under RCP scenarios showed that the amount of this variable under the RCP2.6 scenario compared to the base period, slightly decreased and under the RCP4.5 and RCP8.5 will have a slight increase. ETp of this basin according to stations in Ardabil, Ahar and Khoi will have a decreasing change and an increasing change in ParsAbad and Jolfa. The amount of this increase was estimated to be 29 mm at ParsAbad and 12.2 mm at Jolfa. The monthly ETp of the basin in the future period was estimated to increase approximately in January, April to June and August with a range between 0.1 to 24.3 mm maximum compared to the base period, and if the scenarios occur in the future period, this increase means an increase in the water requirement of plants in the future period in during the growing season, a decrease in infiltration and an increase in evaporation of water resulting from rainfall and a decrease in the feeding of aquifers.