模糊标识指数与对应分析法在水质评价中的联合应用

水质评价对判断水体的污染状况,了解其污染程度和成因有重要的意义,并可为水资源管理及水污染控制提供科学依据,而适当的评价方法是保证评价结果科学合理的关键.因此,本文以青山湖流域为例,在单因子指数法、综合指数法、灰色关联法、改进的模糊层次分析法、水质指数评价法、综合水质标识指数法6种常用水质评价法的结果对比分析的基础上,提出了一种新的模糊标识指数法.该方法结合了改进的模糊层次分析法和综合水质标识法的优点,不仅给出水质级别和水功能区达标程度,而且克服了以往模糊层次分析法存在的低估污染的严重性及不能评价劣Ⅴ类水质的缺点,更加适用于水质状况的评价.同时,在模糊标准化处理基础上,采用对应分析法,将采样点与变量有机地结合起来进行分析.结果表明,青山湖流域的总体水质状况以劣Ⅴ类为主,总体水功能区达标率仅10.34%,流域根据受污染情况被分为3个区,Ⅰ区、Ⅱ区、Ⅲ区的主要污染因子分别是TN、NH4+-N与COD、TP.模糊标识指数法与对应分析法的联合应用可以全面分析流域水质状况,给出科学合理的评价结果.

Combination and application of fuzzy identification index and correspondence analysis method in water quality evaluation

Water quality evaluation is of great significance for determining water quality, the level of water pollution and their cause. Appropriate evaluation method is critical to ensure scientific and reasonable evaluation conclusions. This paper proposes a new method-Fuzzy Indentification Index method (FIIM), which is based on comparative analysis of evaluation results with six commonly used water quality evaluation methods. In particular, by conbining the advantages of the improved fuzzy analytic hierarchy process and the comprehensive water quality identification idex method, FIIM not only estimates the level of water quality and the degree of compliance of water fuctional areas, but also overcomes the shortage of FIIM which often fails to underestimate the level of seriously polluted water and unables to evaluate the inferior Ⅴ water quality. Based on the fuzzy process standardized data analysis followed with the correspondence method to analyze the relationship between sampling points and variable index, water quality of Qingshan lake basin is analysed with FIIM. The evaluation has revealed that the overall water quality were mainly at Grade sub-Ⅴ, with the standard-reaching rate of water function area only 10.34%. And the basin was divided into three zones with the main contamination factors were TN, NH+4-N and COD, and TP, respectively. The combined appliation of fuzzy indentification index and correspondence analysis method can comprehensively analyze basin water quality with scientific and reasonable evaluation conclusions.