Analysis of Spatial and Temporal Characteristics of Drought in Northwestern Liaoning Based on MODIS Data

The ecological environment in the northwest of Liaoning Province is very sensitive and fragile, it is a national first-level ecologically fragile zone, and the frequency of drought disasters is high. It has great destructive power to the healthy development of agriculture, affects the overall crop development and grain reserve in Liaoning Province, and endangers the stability of production, life and economy. According to the regional characteristics, based on MODIS data to monitor the drought situation of cultivated land, select four periods of data in 2002, 2009, 2014 and 2019, extract NDVI and LST to build a Ts-NDVI index model, calculate TVDI, and study the degree of drought in northwestern Liaoning. spatial variation characteristics. The results show that: (1) The drought grades in northwestern Liaoning are mainly extremely arid and arid, showing transitional changes of extreme arid, arid and normal from the central part of the region to the surrounding areas, mainly concentrated in the middle and lower parts of northwestern Liaoning. (2) In 2009, the combined area of extremely arid and arid areas accounted for the largest proportion, and the degree of drought was relatively large, accounting for 88.82%.