The vulnerability evaluation of regional geo-environment: a case study in Beihai City, China

The vulnerability evaluation of regional geo-environment is a important tool for geo-environmental protection and management, and provides scientific basis for decision makers on the regional development planning in the future. This paper presents a first attempt to construct a prototype framework that can evaluate geo-environment vulnerability with the aid of spatial analysis tool of GIS and the analytical hierarchy process (AHP). Proposed framework is significant tool in the complicated evaluation process of geo-environment vulnerability. Moreover, a new method, named the AHP—index accumulation method (IAM)—difference method, is proposed to evaluate geo-environment vulnerability. This method can provide help for other studies on geo-environment vulnerability evaluation. The major results are as follows: high vulnerability zone accounts for 2.5% of the total study area, where over-exploitation of groundwater causes seawater intrusion; medium vulnerability zone accounts for 39.4%, and located in Wujia Town, Shiwan Town, Datianping Village, Hepu County, Zhakou Town and Gongguan fault belt, where collapse and landslide are likely to occur, seawater intrusion is more prone to occur in Nangkang Basin, collapse and seawater intrusion are more prone to occur in Weizhou Island; the remaining areas is under the low vulnerability and stable area, accounting for 58.1%. Based on the results of vulnerability evaluation, three protection districts and corresponding protection recommendations are proposed for geo-environmental protection and management. The vulnerability map is significant to land use planning and environmental management.