مشخصات پژوهش

The aim of this research was to determine the effective drought indices such as NDVI, VCI, EVI, TVX, VTCI, VHI, TCI and NVSWI based on some criteria. The satellite-based drought indices have different data from vegetation and temperature conditions. Linear and trend analysis showed that satellite-based drought indices based on vegetation condition were not more efficient indices such as NDVI and VCI. It can be said that the indices with combination of vegetation and temperature condition have more efficiency. A good agreement was observed among drought indices and precipitation in the arid and semi-arid climatic regions. Application of NDVI, VCI and EVI was limited for real time drought monitoring. Investigation the topographic effect on drought indices indicated that VTCI and NDVI had maximum impressed from height variations. The synthesized drought indices based on effective indices led to better performance. Drought indices investigation using different criteria indicated the high performance of NVSWI, TCI, VHI and TVX. The indices have high correlation with each other. Therefore, using one of them is suitable for drought monitoring