An Analysis of Water Environment Factors and an Evaluation of Water Quality of Aiyi River

Based on the investigation of the water environment factors and aquatic biodiversity of the Aiyi River from March to November 2012,the principal component analysis is selected to analyze the water environment factors of Aiyi River.The fuzzy comprehensive evaluation method is used to evaluate the water quality of Aiyi River.The result shows that the water environment factors which causes water environment pollution of Aiyi River can be divided into four types.The factors which causes organic pollutants are Secchi-depth(SD),Suspended solids(SS),Potassium permanganate index(CODMn),5days biochemical oxygen demand(BOD5)and total phosphorus(TP).The factor causes Planktonic algae pollution is Chlorophyll a.The factors which causes nitrogen nutrient pollution are total nitrogen(TN)and ammonia nitrogen(NH3-N).The factors which causes dissolved salts pollutants was electrical conductivity(EC).The water environmental factors followed by the importance which affects water quality of Aiyi River are arranged as follows:TP,EC,NH3-N,TN,CODMn,BOD5,SS,Chla,SD.The water environment factors which plays a leading role in water quality of Aiyi River are nitrogen and phosphorus nutrient.The comprehensive evaluation result of Aiyi River water quality is Class V.The total nitrogen content exceeded criterion leads to water pollution of Aiyi River.