Assessment And Simulation Of Temporal And Spatial Variation For Urban Water Security In Karst Area 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.First,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.Second,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.Third,we established a water safety system model for Guizhou Province,China to analyze influencing factors,main driving factors and system variation law under the effect of these factors using system dynamics(SD)methods.We simulated the water safety system from 2005 to 2025 under four scenarios(Guiyang model,Zunyi model,Bijie model and concerted development model).The results show that: in the terms of temporal angle,from 2005 to 2010,water resource sub-system is stable.The situation of water environment sub-system is improving and water disaster sub-system is mutable in Guizhou province.Then,in terms of spatial angle,three cities are “safe”;four are “acceptable” and two are “unsafe” in the comprehensive situation of water security.The distributing characteristics of urban water security is gradually turning better from west to east and from north to south in Guizhou province.At last,the major driving factors of the water security system in Guizhou include the agricultural irrigation water demand,soil and water losses area,ratio up to the standard of water quality and the investment of environmental protection.The concerted development model is the best solution for water security system by 2025 in Guizhou under the four scenarios.