应用层次分析法综合评价河流沉积物污染状况

应用层次分析法,以天津滨海新区新河干渠沉积物为例,以各类污染物在沉积物中的生态效应区间值为标准确定各指标的权重,并结合污染物的实际含量对沉积物的污染状况进行定性、定量评价. 计算结果表明,权重最大的3个指标分别为DDD(权重为0.359)、DDE(权重为0.168)和金属汞(权重为0.105)；得分最高的3个指标为总氮(0.034)、镍(0.030)和DDD(0.012)；三大类指标得分依次为营养元素(0.040)、重金属(0.043)和持久性有机物(0.012)；新河干渠沉积物污染综合评价得分为0.095. 评价结果表明,新河干渠沉积物总体上产生不利生态效应的可能性较低,产生不利效应的主要污染物为总氮、镍和DDD. 与单项指标评价相比,层次分析法综合评价体系突出了营养元素类污染物在沉积物环境风险中的贡献. 

Application of Analytic Hierarchy Process on Comprehensive Assessment of Sediment Pollution in a River

Analytic Hierarchy Process(AHP) was used in this study to assess the sediment pollution in Xinheganqu River of Binhai New Development Area,Tianjin,China.The weights of indicators were determined by using effect range levels as the standard.Sediment quality could be assessed qualitatively and quantitatively using the weights according to concentrations of various contaminates in the sediment.The calculation results showed that the indicators with the top three weight values were Dichlorodiphenyldichloroethane(DDD,weight value 0.359),Dichlorodiphenyldichloroethylene(DDE,0.168) and mercury(0.105).The indicators with the top three highest scores were total nitrogen(0.034),nickel(0.030) and DDD(0.012).The scores for the three categories of contaminants were 0.040 for nutrition elements,0.043 for heavy metals and 0.012 for persistent organic pollutants.The comprehensive assessment score of sediment pollution in Xinheganqu River was 0.095.The results showed that the ecological risk posed by sediments of Xinheganqu River was relatively low,and the primary pollutants were total nitrogen,nickel and DDD.In comparison with a single index assessment,the contribution of nutrient pollutants to the overall environmental risk of sediment was more pronounced when using AHP method.