ANALYSIS OF SPATIOTEMPORAL CHARACTERISTICS OF DROUGHT IN AN ARID REGION OF NORTHWEST CHINA

Drought, as a natural disaster, affects the local environment and agricultural production. Drought monitoring plays a crucial role in preventing and mitigating drought, especially Meteorological and Agricultural Drought (IMAD) monitoring. To better monitoring IMAD, a new comprehensive drought index, called Meteorological and Agricultural Drought Index (MADI), was developed in this study, which combined the Standardized Precipitation Evapotranspiration Index (SPEI) and the Temperature Vegetation Dryness Index (TVDI). And, the spatiotemporal characteristics of drought were analyzed by the methods of the frequency, comparison and regionalization in Gansu Province of China during 2000-2016. The results showed that: (1) The meteorological and agricultural drought always occurred, while there was a difference in time of appearance; the IMAD in Gansu Province was mainly light and moderate, becoming serious from southeast to northwest. (2) MADI was temporally well-matched to the drought affected area, soil moisture and NPP. (3) The IMAD based on MADI can reflect both meteorological and agricultural drought well in time and space. (4) According to the drought frequency, the study area was divided into six regions, and most of the study area was the stable drought type. For different regions, government should take timely measures to prevent drought.