Research progress on drought indices
干旱监测指数研究

Global drought disaster is increasingly severe, and becomes a hotpot which many scientists and governments pay more attention to. This disaster has directly threatened our existent environment, but how to effectively detect and monitor its occurrence and evolvement on a global or continental scale is still an embarrassment for us. In this paper, the traditional drought indices such as Palmer Drought Severity Index (PDSI), Crop Moisture Index (CMI), Standardized Precipitation Index (SPI) and Surface Water Supply Index (SWSI) were reviewed, with their advantages and disadvantages analyzed. The drought indices based on remote sensing were divided into two classes, one was based on the reflectivity and emissivity of land surface, such as Vegetation Condition Index (VCI), Temperature Condition Index (TCI) and Vegetation Temperature Condition Index (VTCI), and the other was based on the energy balance model of land surface, such as soil heat inertia index, evaporative fraction index and crop water stress index. The mechanisms, methodologies, and application ranges of these drought indices in remote sensing monitoring were introduced, and the disadvantages and future development of different drought indices were discussed.