Spatiotemporal characteristics of drought under different vegetation types and responses to climatic factors in Jilin Province, China

Drought, as one of the main natural hazards faced by human beings, results in grassland degradation, crop yield reduction, forest activity weakening, and even forest mortality. Utilizing drought indices to identify drought is pivotal for improving ecological protection and hazard mitigation. The temperature vegetation drought index (TVDI) is a remotely sensed index that has been widely applied in monitoring drought and assessing its severity. In this study, the TVDI was utilized to investigate drought across different vegetation types from 2001 to 2020 in Jilin Province, China, and to demonstrate the applicability of the TVDI in this region. Our results showed that the drought degree of different vegetation types showed distinct differences. The forest area experienced lower incidences of drought, whereas the grassland and cropland areas exhibited higher incidences of drought. The variation trends of drought were different in Jilin Province from 2001 to 2020. The increasing trends of drought were mainly distributed in the grassland and cropland, while declining trends of drought were mainly distributed in the forest. The impacts of climatic factors on the TVDI differed among different vegetation types. Evapotranspiration (ET) was the main influencing factor for the TVDI in the forest area, and air temperature played a dominant role in the TVDI in the grassland and cropland areas. The cropland biomass was more susceptible to drought stress than that in grassland and forest areas. This study will serve as a valuable reference for assessing the applicability of approaches to identifying regional drought events.