Effects of Climate Change on Drought Duration and Severity in Arid and Semi-arid Stations (Bandarabbassand Shahrekord), Based on HADCM3 Model

The aim of this paper is assessment and comparison of potential impacts of climate change on drought indices in an arid and a semiarid station. For this purpose, daily data of minimum and maximum temperature, sunshine and precipitation are used. This data were downscaled statistically by using LARS-WG model based on A2, B1 and A1B scenarios. These climatic parameters are projected for 2011-2040, and RDI index was extracted for both observed (1961-1990) and projected data from HADCM3 model. The research outcomes show drought severity has increased under each scenario in both stations, except for Shahrekord under B1 scenario. For Bandarabbbas station, percent of droughts are about 6.7, 10 and 10 under A1B, A2 and B1 scenarios respectively. This parameter is 6.7 and 3.3 percent under A1B and A2 in Shahrekord station and the number (percent) of droughts will decrease about %10 under B1 scenario in this station.