The assessment of water security in karst region by SPA model:A case study of Guizhou Province

Water resource is irreplaceable in natural ecosystem and socio-economic system. Its safety is of great importance. According to the concept of water security, the water security system is divided into three parts, i.e. water resource sub-system, water environment sub-system and water disaster sub-system. The three sub-systems are interrelated and interacted, forming the complex and dynamic water security system. Based on the basic principle of water security and the specific water circulation mechanism in karst area, this paper improved the “DPSIR" model to establish the evaluation index system of water security in Guizhou karst area. The five types of indicators fully describe the comprehensive situation of water security. Using set pair analysis theory, the hierarchies of water safety status in Guizhou were divided into five grades: very safe, safe, acceptable, unsafe and very unsafe. The results demonstrate that: (1) in terms of water resource, four cities are “safe”; two are “acceptable”; two are ”unsafe”; one is “very unsafe”. (2) In terms of water environment, two cities are ”safe”; four are “acceptable”; three are ”unsafe”. (3) in terms of water disaster , four cities are “safe”; two are “unsafe”; one is “acceptable” and one is “very safe”; one in crisis. (4) In terms of comprehensive water security, three cities are “safe”; four are “acceptable”; two are “unsafe”. The status of water security is closely related to the social and economic development.