五元联系数在长江下游生态航道评价中的应用

Application of five-element connection number to assessment of ecological waterway in the lower reaches of Yangtze River

针对生态航道评价中存在的模糊、不确定性问题,基于集对分析理论和层次分析法,建立了五元联系数模型,根据生态航道评价指标体系各指标与等级标准的联系程度,构造联系度公式,结合层次分析法计算各评价指标的权重,运用该模型开展了长江下游南京-浏河口段生态航道评价,结果表明,南京-浏河口段生态航道等级为Ⅲ级,其中航运功能、自净功能和景观娱乐功能为Ⅰ级,生态功能为Ⅳ级,需要结合该河段实际情况加强生态环境保护工作。敏感性分析表明,功能层权重的小幅度波动不会对评价结果造成较大影响,说明对该河段的评价结果比较稳定。

Aiming at the fuzzy and uncertainty problems in ecological waterway assessment,we built a five-element connection number model on the basis of AHP(Analytic Hierarchy Process)method and the SPA(Set Pair Analysis).According to the connection between each index of the ecological waterway assessment index system and the grade standard,we constructed the connection degree formula,and calculated the weight of each assessment index by AHP.The model was applied to assess the ecological waterway of Nanjing-Liuhekou reach in the lower reaches of Yangtze River.The results showed that the health condition of this ecological waterway was in Grade"III".The navigation function,self-purification function,and landscape&entertainment function were in Grade"I",while the ecological function was in Grade"IV".It is necessary to strengthen ecological environmental protection of the reach.A sensitivity analysis indicated that the assessment results were not sensitive to small-amplitude fluctuation of the weights of the function layer,suggesting that the evaluation results of the Nanjing-Liuhekou reach were stable.