Discussion on evaluation for emergent resistance of urban raw-water system on pollution accident

"Emergency resistance" of urban raw-water system (URWS) is used to character the ability of a URWS is possessing with to safeguard itself against sudden strike from outer environment. This paper describes and analyzes URWS by conducting the theory of periphery (boundary and shell, or JIEKE), and presents a comprehensive similarity evaluation model for measuring the resistance of URWS based on theory and methodology of vague sets. Taking the URWS of Chengdu city as an application, this paper builds up an index system for valuing the emergence resistance of URWS; analyzes pollutant spreading and diffusing in different condition of designed scene through numerical simulation; structures relation functions and calculates vague values for each index; calculates and analyzes with similarity model for evaluation the emergent resistance of URWS. The result shows: the evaluation model is available for describing and measuring the ability of emergent resistance for an URWS on unexpected pollution accident reasonably.