Abstract
Climate change has significant effects on hydrological cycle components especially the evapotranspiration, which is quite important in maintaining food security and environmental management in diverse ecosystems. The aim of this study to evaluate several CMIP6 models in projection of ETp under two scenarios: SSP2-4.5 and SSP5-8.5 in the Karkhe basin, Iran. Observed data of 12 synoptic stations across the basin for 1995 to 2014 was obtained for estimation of ETp using the Penman-Monteith (PM) equation as a accuracy metric of CMIP6 models. Three future periods from 2020 to 2100 were chosen for projections. Model bias was corrected using linear scaling (LS). Models were compared and ranked by statistics including, RMSE,and MSE. Based on results the HadGEM-G31-MM-2, GFDL-ESM4, UKESM1-0-LL, and CNRM-CM6-1-HR models ranked as the best models in projection ETp. These models had RMSE values of 0.57, 0.54, 0.6, 0.63 mm respectively . Also, the ESMvalTOOL was used to rank the models in the Karkhe basin, winch provided acceptable results. The two best models selected based on metrics used by this tool are HadGEM-G31-MM-2 and UKESM1-0-LL.The HadGEM-G31-MM-2 model performs well in semi arid and cold Mediterranean climates,GFDL-ESM4 model provided better projections in Mediterranean climates, and UKESM1-0-LL model is suitable for temperate arid. According to the models outputs, ETp would significantly rise in all stations during winter and spring except for the Bostan station, under two scenarios, especially in 2040-2079. In general, warmer weather predominantly leads to substantial increases in ETp in the region which should be considered in future environmental planning.
Details
Presentation Type
Paper Presentation in a Themed Session
Theme
Assessing Impacts in Diverse Ecosystems
KEYWORDS
Evapotranspiration, Climate Change, Climate model, Bias, Scenario
