Study On Water Quality Trend And Pollutants Consists In Liao River Source Area

In recent years, with economy and society development, water pollution is moreand more serious in the source area, which brings a great impact on economy andsociety sustainable development of Jilin Province and Liaoning Province. To study onwater quality trend and pollutants consists in Liao River source area can provide somescientific bases to establish water management policies.Firstly, in order to ascertain main pollution factors, single factor evaluationmethod is used to evaluate the water quality of Liao River source area from2005to2010. Secondly, according to the evaluation results, seasonal Kendall test is adoptedto analyze the water quality trend in the source area. Thirdly, in order to analyze themain source of pollutants and reduction capacity, it’s necessary to investigate andanalyze the point source pollution and estimate non-point source pollution with runoffdivision method.The trend analysis results show that, in full year test,50%of the section’s CODand ammonia nitrogen show a downward trend. In COD test, Huihekou section, Linjiasection and Liujiazi section decline significantly. In ammonia nitrogen test, SishuangBridge section decline significantly. By comparison, in source area, the upstreamwater quality is deteriorating, while the downstream water quality is getting better.According to the non-point source pollution estimation results, in upstream of EastLiao River, non-point COD’s proportion is about50-65%and non-point ammonianitrogen’s proportion30-50%, while in downstream of East Liao River, non-pointCOD’s proportion is about60-85%and non-point ammonia nitrogen’s proportion60-75%. Therefore, non-point source pollution is the main pollution source of LiaoRiver area. Non-point source pollution changes a lot in different year. By Pearsoncorrelation test, interannual non-point source pollution a strong correlation withprecipitation and flow. The inter-monthly non-point source pollution also changes a lot. Non-point COD’load are mainly concentrated in July and August with an inverted"V" shape. Non-point ammonia nitrogen’s load usually has two peaks with an "M"shape. One is from March to April, and the other one is from July to September. Thus,it should be in a different time period to control non-point COD and ammonianitrogen. The research results can provide technical support for water pollutioncontrol in Liao River source area.