The effect of climate change on meteorological parameters and drought in Golestan province

This research was conducted to evaluate changes in minimum and maximum temperatures, precipitation and drought severity (SPI index) in Golestan province during 2016-2045 period compared to the 1986-2015. For this, the output of HadCM3 and ECHO-G models under A2 scenario downscaled by LARS-WG model in 15 meteorological stations. The ability of the models for prediction of parameters using different statistics was appropriate. Based on the forecasts of HadCM3 and ECHO-G model, the annual average of minimum temperature by 0.4 and 1.6 and maximum temperature by 0.2 and 0.7°C will be increased, respectively. Also, these models predicted increment (30.9 mm) and reduction (11.8 mm) in the annual precipitation, respectively. Models predictions showed that decrease of occurance percents of dry and wet periods and increase of normal period will be occured in monthly scale. However, in yearly scale, increase of occurance percents of dry and wet periods and decrease of normal period was predicted. Also, variation of occurance percents of different drought classes in future period in ECHO-G model was more than HadCM3 model. Results showed that most frequency (area) of annual precipitation in basic period and ECHO-G model ranged between 350-550 mm while in HadCM3 model was in range of 450-650 mm. Maximum of precipitation changes were seen in the cities of Bandar Gaz and Maravetappe under prediction of HadCM3 and ECHO-G models, respectively.