Forecasting drought years of Zanjan province during the period 2011 - 2050 using outputs of Statistical downscaling model (LARS-WG)

According to studies and research of Hadley Climate Prediction Center, in the 21st century, pervasive and severe drought, will be threatened the lives of millions of people around the world because of global warming. Forasmuch as the drought affects different sectors of society, therefore, monitoring and evaluation of this phenomenon in the future to proper planning is essential. To this end, the climate data should be produced for future periods. In this study, using the output of GCM models and downscaling them to help LARS-WG model, rainfall data was simulated over the period 2050 - 2011 for four stations in Zanjan province. Since there are uncertainty in climate studies, to achieve more certainty in the results, was used from different outputs of GCM models with different emission scenarios. According to, in this study, the four Coupled Ocean-Atmosphere GCM models (BCM2, HADCM3, HADGEM- A1 and IPCM4) and their different scenarios was used. To determine the best model, was used inverse of absolute error of each model. And finally the model that has the highest weight factor, were selected as the best model for the study of future and the downscaling and generating of climate data and to study drought. The results indicate that the climatic parameter of precipitation over the next 40 years is decreasing relative to the base period (Since the establishment of the stations until 2014), forecasted with minimum reduction for Zanjan station by 2 mm and the maximum reduction for Khodabandeh and Mahneshan station by 24 mm. In order to study and evaluate the drought state of Zanjan province, SPI and PN were used during this period. The results show that these two drought indices are consistent with each other well, and over the next four decades, we will see for at least a drought decade.