Investigation of Climate Change Effect on Drought Characteristics in the Future Period using the HadCM3 model (Case Study: Khoy Station, Northwest of Iran)

     Investigation of drought event has a great importance in the natural resources and water resources management and planning. In this research, the effect of the climate change on drought characteristics in Khoy station was investigated using the HadCM3 model under B2 scenario. The statistical downscaling was executed using SDSM 4.2.9 and observed daily precipitation, observed predictors and large-scale predictors derived from the HadCM3 model. Afterwards the SPI was calculated for different time scales of 3, 12, 24, 48 months in the observed period of 1977-2006 and also three periods of 2007-2036, 2037-2066 and 2067-2096. The results show that the mean annual precipitation will decrease in the future periods, in the manner that the fourth and second periods respectively with the depletion of 48 mm (17%) and 34 mm (12%) than the observed period have maximum and minimum rate of the depletion. The results also show that the drought occurrence with more intensity, duration and frequency can occur in the future periods.