SPATIAL AND TEMPORAL VARIATIONS OF NDVI AND ITS RESPONSE TO CLIMATIC FACTORS IN THE LIJIANG RIVER BASIN, CHINA, FROM 2000 TO 2022

Understanding how vegetation changes over time and adapts to climate variations is vital for the preservation of ecosystems and ensuring long-term sustainability.However, there is little research on the Lijiang River Basin, particularly regarding seasonal-scale studies.Using MOD13A1 NDVI data (2000-2022), this study examined the NDVI's spatiotemporal changes over the previous 23 years in the Lijiang River Basin, utilizing techniques such as trend analysis, coefficient of variation, and partial correlation.Additionally, it assessed how climate change impacted NDVI.According to the results, the NDVI increased by about 0.2% annually between 2000 and 2022, indicating a positive trend over the Lijiang River Basin.Over 97% of the region exhibited relatively low variability, with areas of significant NDVI increase or decrease concentrated in regions with intensive human activity.Vegetation cover changes were influenced by both human construction and plantation forestry.From 2000 to 2022, the NDVI values indicated high vegetation coverage, with more than 97% of the area displaying medium to high vegetation (NDVI > 0.6).At the inter-annual scale, temperature exhibited a stronger positive correlation with NDVI.Seasonally, the relationship between temperature and NDVI was strongest during spring and summer.In contrast, although temperature and rainfall showed positive correlations with the vegetation index in fall and winter, rainfall exhibited a stronger relationship during these seasons.