Document Type : علمی - پژوهشی


دانشگده علوم انسانی /دانشگاه یزد/


Due to the statistical limitations of the data of the Grace satellite, a common time period of 16 years was chosen from 2002 to 2017. Two indices VHI and TSDI were obtained a high correlation in the south, center and some areas of the north. Finally, results of the research were validated by GLDAS data of moisture of soil and SPEI standardized precipitation-evaporation and transpiration index. Then, graph changes of the SPEI index was calculated in a long-term period of thirty years (1987-2018) and the studied time period was separated from 2002 to 2018. The results showed that the SPEI index and data of moisture GLDAS have a high agreement with the VHI and TSDI indices. Also, the maps and charts showed that this province is facing severe meteorological, agricultural and hydrological droughts, and the deficit trend of the total storage of underground water, especially since 2012, has been very dry and exceptional. This point doubles the planning spaicially in the restoration of underground water.