基于“边际效益递减”原理的城市水安全评价方法研究

通过城市水安全内涵剖析和系统分析，将城市水安全系统分为支持子系统、协调子系统和防洪子系统，建立了逻辑清晰、层次分明的评价指标体系，并选用层次分析法确定了各层次指标的权重。在分析指标变化对城市水安全的影响规律的基础上，借鉴“边际效益递减”原理，建立了一种新的指标评价方法与模型。利用所确立的评价方法，对昆明城市水安全的现状及趋势进行了评价与预测，其得分为0.574，处于“不安全”状态，且呈恶化趋势，该评价结果与实际相符，证明了该方法体系的科学性和可靠性。

Study on the Evaluation Method of urban water safety based on Law of Diminishing Marginal Utility

Based on the connotation and system analysis, the urban water safety system has been divided into three subsystems, the support subsystem, the coordinate subsystem, and the flood control subsystem. The evaluation index system with clearly logic and hierarchy has been built, and the weight of each hierarchy was confirmed by the analytical hierarchy process (AHP). A new index evaluation method and model has been established based on the effect analysis of the index change to the urban water safety and the law of diminishing marginal utility. The current situation of urban water safety and its trend in Kunming has been evaluated and predicted by the new evaluation method. The result shows that the score is 0.574 (full score is 1), under an unsafe status, and the situation will be more serious. The evaluated result is coincident with the true situation of Kunming, which proves the scientific and reliability of the evaluation method.