Meteorological Drought Monitoring and Spatial Analysis Using by SPI, ZSI, and EDI (Case Study: Isfahan Province)

Water shortages and droughts can cause serious crises in human life. Drought is a reversible phenomenon that can indirectly lead to social crisis and public health risks and have negative effects on the environment, ecology, and so on. In this research, in order to analyze meteorological drought in Isfahan province, precipitation data of 21 meteorological stations were used for the period of 1993-2017 and EDI, SPI and ZSI indices were calculated using MATLAB codes. Kriging estimator which is the best estimate for drought zoning based on literature reviews, was used to provide isovalue map of different calculated indices in ArcGIS10.3. The results showed that severity of the EDI, SPI and ZSI indices are different. Based on SPI values and drought intensity classification, the area faced moderate and severe drought classes during 1993 to 2017 has increased by 2.7 and 16.1 percentage respectively. ZSI values showed that, the region experienced moderate, severe, and extreme drought during the study period has decreased by 95.9, 95.1, and 97.3 percentage respectively. Based on EDI values showed that, main region of the province in 1992, 2006, and 2017 faced extremely wet, extremely wet, and severe drought with the area of 33.6, 49.8, and 44.6 percentage respectively.