The effects of climate change on temperature, precipitation and drought in the the future Shadegan basin

In this study, to evaluate the effects of climate change on temperature, precipitation and future droughts in Shadegan Basin, output of the MPI-ESM-LR، BCC-CSM1-1 and NORESM1-M general circulation models under diffusion Scenarios RCP4. 5 and RCP8. 5 is used. The outputs of general circulation models are downscaled using LARS-WG software. To evaluation of drought, the standardized precipitation index (SPI) is used for the base period (1986-2005) and Future period (2020-2039) and in time scales of 6, 12 and 24 month. The results showed that the maximum temperature and minimum temperature increased in all months the future period under RCP4. 5 and RCP8. 5 scenarios in the Shadegan Basin. Precipitation changes do not show a general increasing or decreasing trend. The results showed that under RCP4. 5 scenario and in time scales of 6, 12, and 24-month, respectively 17. 16, 14. 70 and 18. 74 percent of all months the future period would be dry. In addition, Under RCP8. 5 scenario and time scales of 6, 12, and 24-month, respectively 16. 45, 17. 03 and 15. 21 percent of all months the future period will be dry. The months of dry under RCP4. 5 and RCP8. 5 scenarios in future period, in time scale 6-month respectively 2. 27 and 1. 56 percent will be increase, in time scale 12-month respectively 2. 77 and 0. 44 percent will be decrease and in time scale 24-month respectively 2. 00 and 5. 53 percent will be decreased. So anticipated under climate change in future period, the number of drought months is less than the number of months with normal and wet conditions.