Abstract: The vulnerability of Xijiang River drainage basin in Guangxi, China is evaluated in this paper by using spatial principal component analysis and analytical hierarchy process in association with GIS technology.The evaluation index system comprises indicators involved in ecology, resource, and disaster. The vulnerability is classified into five levels in order: potentially vulnerable, slightly vulnerable, mildly vulnerable, moderately vulnerable, and severely vulnerable. The spatial distribution of vulnerability is examined, and comprehensive treatment suggestions are put forward. As the research shows, slightly vulnerable, mildly vulnerable, and moderately vulnerable area together cover 75.46% of the total basin area, among which moderately vulnerable area is the largest, accounting for up to 29.11%; potentially and severely vulnerable area covers 11.48% and 13.06% of the total area, respectively. The spatial vulnerability distribution is closely related with elevation. With the climbing of elevation, vulnerability exacerbates.

Key words: vulnerability assessment for river basin, GIS for river basin, Xijiang River in Guangxi, spatial principal component analysis, comprehensive treatment, sustainable development