Water Environmental Factors Analysis and Water Quality Evaluation of Mingcuihu Lake

Bsaed on the investigation of the water environment factors and aquatic biodiversity of Mingcuihu lake from January to October 2014, the principal component analysis was selected to analyze the water environmental factors of Mingcuihu lake.The fuzzy comprehensive evaluation method and the gray correlative degree method was also used to evaluate the water quality of Mingcuihu lake.The result showed that the water environmental factors which caused water environment pollution of Mingcuihu lake can be divided into three types. The factors which caused nitrogen, phosphorus nutrient and organic pollutants were Chlorophyll a, total nitrogen(TN), total phosphorus(TP) and potassium permanganate index(CODMn).The factor caused nitrogen nutrient pollution were ammonia nitrogen(NH3-N) and 5 days biochemical oxygen demand(BOD5). The factors which caused dissolved salts pollutants was pH. The water environmental factors followed by the importance which had affected on water quality of Mingcuihu lake ranged as follows: pH,NH3-N,TN,TP,Chl.a,CODMnand BOD5. The water environmental factors which played a leading role on water quality of Mingcuihu Lake were nitrogen and phosphorus nutrient. The comprehensive evaluation result of Mingcuihu lake water quality was Ⅳ class.