The impact of human disturbance on vegetation was classified and assessed based on vegetation variations and its driving factors using cluster analysis method, and a case study was conducted in Northwest Guangxi of China. First, the linear regression slope of NDVI and RUE from 1999 to 2012 was calculated to analyze the change trend. Second, three layers including the slope of NDVI, the slope of RUE, and population density were stacked using GIS technique, and the stacked layer was classified into 21 groups using cluster analysis method. Third, human disturbance intensity of each group was preliminarily judged based on the trend of NDVI and RUE. Finally, the groups were reclassified into seven grades based on population density. Results show that (1) At a regional scale, the vegetation in study area showed an overall improvement but local degradation trend from 1999 to 2012. (2) Annual RUE increased from southeast to northwest in space and showed an increasing trend in time. (3) Human activities have more positive effects than negative effects on vegetation in study area from 1999 to 2012. The distribution of the positive effects shows a multi-centered pattern, which includes northeast part with Mulun National Nature Reserve and Jiuwanshan National Nature Reserve as the center, northwest part with Jinzhongshan National Nature Reserve as the center, and west part with Wanglaoshan National Nature Reserve as the center. The negative effects are mostly distributed in southeast and southwest part especially in Duan county and Jingxi county. The positive and negative effects show a scattered distribution pattern in the middle part of study area and the intensity of human disturbance in this part are mostly classified into non-significant disturbance grade. (4) Human activities are mostly distributed in the areas with a slope of 25 below, high-intensified positive disturbances are concentrated in hill and low mountain areas with an elevation between 400 and 1000 meters, and high-intensified negative disturbances are concentrated in middle- or down-slope of the hills, valley basins, and Karst peak cluster-depression areas.
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