[Spatial and temporal changes of the ecological vulnerability in a serious soil erosion area, Southern China.]

Research on eco-environment vulnerability assessment contributes to the ecological environmental conservation and restoration. With Changting County as the study area, this paper selec-ted 7 indicators including slope, soil type, multi-year average precipitation, elevation deviate degree, normalized difference vegetation index, population density and land use type to build ecological vulnerability assessment system by using multicollinearity diagnostics analysis approach. The quantitative assessment of ecological vulnerability in 1999, 2006 and 2014 was calculated by using entropy weight method and comprehensive index method. The changes of the temporal-spatial distribution of ecological vulnerability were also analyzed. The results showed that the ecological vulnerability level index (EVLI) decreased overall but increased locally from 1999 to 2014. The average EVLI values in 1999, 2006 and 2014 were 0.4533±0.1216, 0.4160±0.1111 and 0.3916±0.1139, respectively, indicating that the ecological vulnerability in Changting County was at the moderate grade. The EVLI decreased from 2.92 in 1999 to 2.38 in 2006 and 2.13 in 2014. The spatial distribution of the ecological vulnerability was high inside but low outside. The high vulnerability areas were distributed mainly in Hetian Town and Tingzhou Town, where the slope was less than 15° and the altitude was lower than 500 m. During the study period, Sanzhou Town had the largest decreasing range of EVLI while Tingzhou Town had the lowest.