Temporal and Spatial Variation Characteristics of NDVI in Qamdo and the Relationship with Climate

Vegetation, as an important part of terrestrial ecosystem, has a profound impact on ecological structure and function. In-depth understanding of the spatial and temporal evolution of vegetation characteristics and its relationship with climate, help to deepen understanding of the ecosystem structure, processes and functions, providing an important reference for the ecological protection and construction. Based on the NDVI data set from 1998 to 2018, and combined with the precipitation and average temperature data of meteorological stations in and around Qamdo, the trend analysis method, catastrophe test method, mean method, partial correlation analysis method and R/S analysis method were used to analyze the spatial-temporal dynamic characteristics of NDVI and their relationship with climate factors in Qamdo for 21 years. The results show that: (1) The NDVI in Qamdo region showed an upward trend from 1998 to 2018, with the improved region accounting for 33.09% of the total area, the degraded region accounting for 36.49%, and the basically unchanged region accounting for 30.42%. (2) NDVI has a negative correlation with annual precipitation and a positive correlation with air temperature. It shows that temperature is a significant climatic factor affecting vegetation coverage in Qamdo area.