Analysis on Change Trend of Water Environment Quality in Main Rivers in Baoji

This paper uses compressive pollutants assessment approach and the monitoring data to evaluate the water quality of Baoji city five main rivers,namely Jianglingjiang River,Weihe River,and three branch rivers,that is Jinliangjiang River, Qingjianghe River and Shibahe River. The results show that the water quality reaches the related standard. The upstream water is better than the downstream. While the downstream water quality reaches the tandard,some pollutants are up to the standard limitation. From year 2009 on,the five river water quality is better than before,and the key pollutants are COD,BOD5, NH3- N and phenol.