Spatial-temporal variation of NDVI and its climatic response in Li River Basin based on GEE

Vegetation serves as a crucial indicator of ecological environment in different regions. Land cover vegetation is significantly impacted by climatic factors and human activities, and good coverage can enhance the quality of the local ecological environment. The Lijiang River Basin is a typical karst landscape with a delicate ecological environment. Describing changes in the characteristics of vegetation cover under different influencing factors carries significant significance for the restoration of vegetation in karst areas, taking the Li River Basin as an example. This study is based on the vegetation NDVI dataset MOD13Q1 of the Li River Basin from 2000 to 2020. Results showed that: over the past 21 years, the Normalized Difference Vegetation Index (NDVI) mean value in the Li River Basin was around 0.85. The Li River Basins inter-annual growth rate was 0.011/10yr; nevertheless, there are substantial discrepancies among regions. Vegetation was notably more impacted by temperature than precipitation in terms of land cover. NDVI exhibited a decline trend from the central area to the peripheral areas. Additionally, there was a lack of vegetation cover on the upper, western side of the middle reaches, and eastern side of downstream.