Agricultural Drought Frequency, Duration analysis in Karoon 3 Watershed under climate change

The aim of this study is investigation of climate change impact on Karoon3 basin in future periods. For this purpose, the simulated precipitation and potential evapotranspirationof four AOGCM models was used to simulate drought index. Monthly precipitation was calculated by inverse distance weighted method. Reclamation Drought Index (RDI) was used as watershed drought index. RDI was calculated in 12 months periods. LRAS-WG5 model was used to downscale data from GCM models. To determine the feasibility of future periods meteorological data production of LRAS-WG5 model, calibration and verification was performed for the base year (1991-2015). Meteorological data simulation for future periods under General Circulation Models and climate change IPCC scenarios was performed and then the drought frequency and intensity using RDI under climate change effects analyzed. Results showed that based on calculated RDI frequency rational to base period will increase 12.3 and 9.2 percent in 2011-2030 and 2046-2065, respectively. RDI in 2011-2030 and 2046-2065 will decrease about -0.8, -1.6 percent respectively.