The application of the Fuzzy Attenuation model in the evaluation of water quality in the Yangtze River

The pollution of the Yangtze river is becoming more and more serious, but there is much uncertain inkling in the evaluation of the Yangtze river which makes it difficult to get the integrated evaluation. The fuzzy recognition sets out its objectivity and practicability during treating with multi-inklings. This paper sets up the fuzzy attenuation model by using the fuzzy recognition and considering the ability of potamic self-purification, meanwhile, using this new model it gets the quantificational integrated evaluation by analyzing the water quality of the Yangtze river from June2003 to Sept.2005. By investigating the content of the main pollution of CODMn and NH3-N in the main stream of the Yangtze river more than one year, we get the analysis of the main pollution sources of CODMn and NH3-N in the main stream of the Yangtze river.