Evaluation of Interpolation Indexes in Droughts Using GIS (Case Study Larestan)

Drought is one of the most important environmental events and also it’s the integral part of climate fluctuations. This phenomena is a specific condition of precipitation loss and high temperature that might happen in every climate condition. Drought condition awareness and drought intensities zoning might decrease risks of drought losses significantly. Present study is an attempt to evaluate accuracy of place interpolation methods for occurred drought intensities zoning in LARESTAN in 1387 using Percentage of normal precipitation Index (PNPI), standard precipitation index (SPI), deciles precipitation index (DPI), and Rainfall anomaly index (RAI). Therefore, it used data of 20pluviometry stations in LARESTAN that distributed appropriately and inverse distance weight (IDW) with 1 to 3 powers, ordinary kriging (OK), and universal kriging (UK) Methods, were studied.