巢湖水体富营养化主要驱动因子的模糊数学评价

Fuzzy Evaluation of Main Driving Factors of Water Eutrophication in the Chaohu Lake

目的客观评价巢湖的氮、磷污染水平,正确反映该湖的富营养化程度,为该湖的水体污染控制及水质改善工程及同类湖泊的水质评价提供参考.方法应用模糊数学方法分别对巢湖12个监测点的总氮质量浓度(TN)、总磷质量浓度(TP)进行评价,同时提出富营养化驱动指数概念来综合反映各监测点附近水体的富营养化程度.结果按最大隶属度原则,大多数监测点的TP属于Ⅲ类污染级别;除新河入湖区外,其他监测点的TN均属于V类污染级别;12个监测点的富营养化驱动指数均大于零.结论巢湖的氮、磷污染均已经达到较高程度,氮污染问题尤其突出,今后迫切需要加强氮污染源的控制.各个监测点附近水体均处于不同程度的富营养化状态;并给出了需要进行重点污染控制的6个监测点.

When it comes to the control of water pollution and water quality melioration, it is important to evaluate the water quality objectively, so the aim of this paper is to evaluate total nitrogen（TN） and total phosphorus（TP） in the Chaohu Lake and to reflect the water eutrophication level in it. Thereby, fuzzy method was adopted to evaluate TP and TN of twelve measure sits in Chaohu Lake and the eutrophication driving exponent （EDE） was originated to present the water eutrophication level. The evaluation result shows that the TPs of most measure sits pertained to Ⅲ pollution level judged by maximal dependence function value principle （MDP）. By the same principle, it also can be indicated that TNs of all the measure sits, except a sit where a new river infloods the lake, were evaluated to be in Ⅴ level pollution. Besides, the EDEs of all the measure sits were above zero. From those results, several conclusions can be drawn： Firstly, both the nitrogen pollution and the phosphorus pollution have reached a high level with the former standing out, so it is urgent to keep nitrogen pollution under control. Secondly, all parts of the Chaohu Lake presented by the twelve measure sits are eutrophic to different degrees and six sits are nominated to be regarded specially.