Sixteenth International Conference on Climate Change: Impacts & Responses

Abstract

Evapotranspiration is important in agricultural water management especially in water scarce regions. The current research assesses the performance of the water management model WEAP for projection of potential evapotranspiration in Karkhe Basin, southwest of Iran. The model was run using projections of two climate model under SSP2-4.5 and SSP5-8.5 climate change scenarios. The required observed meteorological data of selected synoptic stations located in the study basin were collected from Iran Meteorological Stations and used to estimate evapotranspiration using FAO-Penman Monteith equation. These obtained values were used as an evaluation measure of WEAP model performance in estimation of ET. Projected values of potential evapotranspiration using KIOST-ESM and MPI-ESM1-2-LR from CMIP6 project under SSP2-4.5 and SSP5-8.5 scenarios for future period of 2020 to 2100 were retrieved from ESGF climate database and the bias was corrected using delta method. Then these projected values of ET were compared with FAO-PM equation estimations using future period climate data under both climate change scenarios. The corresponding values of RMSE for two models of KIOST-ESM and MPI-ESM1-2-LR under SSP2-4.5 و SSP5-8.5 scenarios were 0.5,0.63.1.09,1.05 respectively which shows higher accuracy of KIOST-ESM model. Among the study stations best performance in ET projection under both scenarios using KIOST-ESM was observed in Khoramabad with RMSE 0.44. for the MPI-ESM1-2-LR model under both scenarios, the highest agreement between projections and estimated values using PM equation was observed in Asadabad station with RMSE values of 0.52 and 0.45 for two scenarios, respectively.