模糊物元识别模型在巢湖水体富营养化评价中的应用研究

Fuzzy pattern recognition model to water trophic grade in Chaohu Lake

选取TN、TP、Chl-a、COD、BOD3、DO和SD等7项指标，应用模糊物元识别模型对2000～2007年巢湖的12个水质监测点的富营养化等级进行了模糊识别。通过与巢湖同期水质浓度变化及其分布区域进行对比分析，验证了模糊物元识别模型在巢湖水体富营养化评价中的适用性。巢湖富营养化评价结果表明，2000～2007年富营养化呈逐年加重的趋势，据采样点模糊物元计算结果得知西巢湖（1#～6#）的富营养化状况比东巢湖（7#～12#）更严重，西巢湖贴近度最高值为0．9974，接近极富营养状态，而东巢湖的最高值仅为0．5866。从年际变化上看，2000～2007年东巢湖富营养化状况变化不大，营养状态级处在较低的水平，而西巢湖的富营养状况变化则较大，营养状态级则处在较高水平。

The research selected total phosphorus, total nitrogen, chlorophyll a, COD, BOD5 ,DO and transparence as evaluation index. A fuzzy matter element model was used to recognize trophic state grades of 12 water quality monitoring stations distributed in Chaohu Lake from 2000 to 2007. Comparative analysis and validation were performed for the change and distribution area of trophic state and those of water quality monitoring indicators in Chaohu Lake at the same time. It could be concluded that recognition results correspond with the practical situation, and could well reflect change of the trophic state grade in spatial-temporal distribution. According to eutrophication evaluation results of Chaohu Lake, the eutrophication trend increased from 2000 to 2007. The fuzzy matter element calculation results showed that the eutrophication in west Chaohu Lake （1# -6#） was more serious than that of the east Chaohu Lake （7# - 12#）. The highest nearness degree of west Chaohu Lake was 0. 9974,it was very near the nutritional status, but the highest nearness degree of east Chaohu Lake was 0. 5866. The eutrophication situation of east Chaohu Lake changed little from 2000 to 2007, but the west Chaohu Lake was opposition.