Review the Efficiency Indices Resulting from Remote Sensing Technology in Evaluation of Meteorological Drought Case study: Sefidroud Catchment area

During the recent years, the drought with destructive effects in management of water resources, environmental, and ecology is considered as a serious crisis. Planning and preventive measures against the drought has a high importance in reducing its effects. In this respect, implementing the proper method of monitoring and drought forecasting can have a substantial effect to deal with this phenomenon. In this study, the information obtained from MODIS sensing images in extracting NDVI, NDWI,, DSI, and VTCI indices have been used for drought monitoring. The objective would be the selection of base index according to the factors associated with causing drought in Sefidroud catchment area for the review and study of drought and its effects. The average defect obtained from the calculations of the earth surface temperature by the use of extended separate window algorithm developed by Prise has been 3.84. The highest correlation coefficient between monthly rainfall with the under study indices is related to VTCI index. Also other under study indices except VTCI index has a time delay in comparing with the time of rain fall occurance. The lowest value of correlation coefficient is related to NDVI index which can be due to the type of dominant vegetation cover in the area under study. Therefore, VICI index because of incorporation thermal features (earth surface temperature) and the obtained information from spectral reflection (vegetation cover index) in the form of proper formulation can be more effective for determining the drought conditions (real time).