Study of drought in Sistan Plain and its impact on Hamoun international wetland

Drought as an important natural phenomenon with a large spatial extension causes considerable damages to different economical parts of our country every year. Therefore, drought monitoring and zoning temporally and spatially should be considered as an essential principle in planning for the country. In this study the Sistan Plain drought severity has been examined using PN, SPI, DPI and RAI indices in order to choose the best index for monitoring the drought in the study area and to investigat the impact of the drought on Hamoun wetlands. The results showed PN index with correlation coefficient of 1 is the better index to expression of drought conditions relative to other indices. Also according to the results, the drought was the main reason of dried up the Hamoun Lake and has been caused many harmful impacts on the natural, physical and socio-economic environments of Sistan plain.