Trends of vegetation dynamics and its response to climate change in Pearl River Basin of southwestern China

Utilizing the Standardized Precipitation Evapotranspiration Index (SPEI) and the Normalized Difference Vegetation Index (NDVI), the variation trend of NDVI, SPEI and the response of vegetation productivity to drought events at different spatial–temporal scales were evaluated by correlation analysis. The results show that the annual change trend of vegetation coverage is obviously mainly distributed in the dense area of the river network, which indicates that the river network is dense and abundant in water, which is beneficial to promote vegetation growth. The vegetation coverage NDVI is related to the drought index SPEI for the same month, and the corresponding month has a strong correlation with the spatial distribution of river networks. The corresponding month appears in autumn in the coastal area, in summer in the middle region, and in spring in the western region. Elevation, distance from coast, and density of river network will affect the response of vegetation productivity to drought events.