Preliminary analysis on water pollution characteristics of Zaohe River in Xi´an

Through analyzing the water pollution characteristics during the flood and non-flood period according to the water quality monitoring results of Zaohe River in Xi´an city from March to August in 2010, the conclusion is that: (1) The water quality of the channel is bad in the study period, and the concentration of the SS,COD, the ammonia nitrogen, the total nitrogen and total phosphorus are exceeded the monitoring range of surface water environment quality standards. (2) The concentration of the COD shows increasing trend, total phosphorus, the ammonia nitrogen and total nitrogen are increased first and then decreased, the nitrate nitrogen has little change from the upstream to downstream. (3) The concentration peak of the NSP is ahead of the flow peak, and the non-point source pollution load rate of the SS, COD, the total phosphorus, the ammonia nitrogen, the nitrate nitrogen and total nitrogen are 44.73%, 33.20%, 14.50%, 25.50%, 9.59% and 13.67% respectively in 20100821 flood period.