Study on vegetation cover change in Yunnan-Guizhou-Sichuan region

Vegetation is an important connecting substance between soil, water and atmosphere, and the study of the temporal and spatial variation of vegetation coverage in Yunnan-Guizhou-Sichuan region can better understand the dynamics and functions of vegetation ecosystems, and provide theoretical support for maintaining ecological balance and vegetation restoration. In this study, MODIS NDVI remote sensing data was used to analyze the changes of vegetation coverage in Yunnan-Guichuan from 2000 to 2020, and the spatiotemporal changes of vegetation coverage in Yunnan-Guichuan were analyzed by univariate linear regression trend analysis and Sen+Mann-Kendall trend analysis. The results showed that: (1) In the past 20 years, the spatiotemporal changes of vegetation in Yunnan-Guizhou-Sichuan region were obvious, and the annual, seasonal and monthly scales showed a fluctuating upward trend. (2) The multi-year mean vegetation index of NDVI in the study area was mainly concentrated in 0.45-0.75, accounting for 81.96%. (3) From 2000 to 2020, the vegetation coverage in the study area showed a significant improvement trend, and the upward trend accounted for 89.57%, which was much greater than the decreasing trend.