A Comparison between Satellite and Climatic Indices in Drought Monitoring



The importance of drought monitoring in a near real-time manner makes the use of remote sensing systems indispensable. In this study, a comparison between SPI and EDI climatic indices (in two time scales of 1 and 3 months) with satellite indices of NDVI, VCI and DEV is made for Tehran province. For this, satellite images of AVHRR on NOAA satellite for 6 years (from 1996 to 2001) are prepared and processed. Furthermore, the simple linear regression and dummy variables regression are applied to correlate climatic and satellite indices. The selection of variables is based on examining all possible equations and the Step by Step method. Results of regression analysis for the study area showed a more significant correlation between NDVI and SPI (3 months), while using dummy variables. Also, the correlation between the indices in regions equipped with more meteorological stations was found to be higher.