The Ecological Vulnerability Evaluation in Southwestern Mountain Region of China Based on GIS and AHP Method

The ecosystem seriously degraded in the southwestern mountain region of China is very vulnerable which has a great impact on regional sustainable development. In this paper, the ecological vulnerability index (EVI) including 13 factors is established synthetically reflecting ecological sensitivity (ES), natural and social pressure (NSP), and ecological recovery capacity (ERC) based on HPA method, and five grades for each factors is classified by expert consultation including potential grad, slight grade, light grade, medial grade and heavy grade. By the means of GIS spatial analysis, cluster analysis and spatial autocorrelation analysis, the regional ecological vulnerability is deeply analyzed in regional level, county level and in grade level. The conclusion is as follows. From the regional level, the ecological condition in southwest of China is relative stable reflected by area proportion of heavy and medial grade significantly less than the area proportion of potential, slight and light grade, which is accompanied by the heavy grade of ES, EP and EVI mainly concentrated in the east-southeast of whole region and four centers with high ecological recovery capacity. From county level, 152 counties are divided into two groups with centroid cluster method whose cluster level is determined by Cubic Clustering Criterion, Pseudo T-Squared Statistic, Semi-Partial R-Squared and Pseudo F Statistics. The first zone with high EVI locates in east-southeast region including 79 counties and the second one with forest, grassland, shrub as dominant land use type rules 73 counties in the west-northwest region where the disturbance from human activity is very scare. From grade scale, the clustering trend for EVI grades is apparent presented by global Moran' I about 0.6271 and the spatial adjacency is dominated by high-high and low-low relation significantly. From above, we can see that there exits the characteristics of regional division of ecological vulnerability in different level from west-northwest region to east-southeast region. So the study set a solid foundation for regional ecological restoration by applying research findings, which is obtained during the period National Key Technologies R & D Program of China during the 10th Five-Year Plan Period. (C) 2010Published by Elsevier Ltd.