Study On Load Estimates And Control The Countermeasure Research Of The Small Basin Non-Point Source Pollution

The non-point source pollution is refers to the water body pollution that Causes by the soluble or solid pollutant remittance progressively the water body at big area precipitation and under runoff washing out effect.Present paper's prime task is to study on the rule and characteristic of the produces and outputs of nonpoint source pollution taking the Beiru River and the Qingyi River located at Xuchang city as an example,and has calculated two basin nonpoint source pollution load by applicating average density law,based on this proposed the agricultural nonpoint source contamination control technology.Has analyzed hydrology and water quality change characteristic,the water quality parameter and the rainfall amount relations as well as Single field rainfall process water quality parameter variation characteristic by using 2008 actual datas of water temperature,pH,DO,conductivity,COD,NH₃-N of the water quality unattended station of the LuDo cross section of the Beiru River and Gao Cunqiao cross section.Looking from the analysis result of the hydrology and the water quality change characteristic,the parameter has not obvious seasonal variation rule besides the water temperature,but conductivity,DO,COD year average value has certain relations with the water time change.The difference of pollution structure creates the difference differently of Hydrology and water quality.As a result of point source pollutant impact,the parameter variation scopes of pH,DO,conductivity,turbidity,COD,NH₃-N of the Gao Cunqiao cross section are big,and the water quality is inferior to Beiru River obviously.By using statistical software SPSS13.0 in Spearman correlation coefficient function Carries on the analysis to the water quality parameter and the rainfall amount size's relevance,discovered that the non-point source pollution and the rainfall amount are closely related.The turbidity,DO, NH₃-N(Lu crosses cross section) and so on parameters are related at remarkable level,and the other parameters have certain relevance,but is not remarkable.Looking from the single field rainfall water quality parameter variation situation analysis, the pollutant density and the total quantity in the rainfall process is increased than the cloudless. The pollutant density and the quantity increase along with the rainfall amount increase,but the different pollutant density maximum value appears the time is different,and certain pollutant density like NH₃-N has certain relations with the rainfall size in the rainfall process.Using the result average density law analysis,The COD,NH₃-N total loai of Beiru river respectively is 256 t,15.9t,the nonpoint source pollution load accounts for the proportion respectively is 70.4%,68.7%,the point source pollution load accounts for the proportion respectively is 29.6%,31.3%.The COD,NH₃-N total loal of the Qingyi River respectively is 1732t,211.8t,the nonpoint source pollution load accounts for the proportion respectively is 17.7%,26.1%,the point source pollution load accounts for the proportion respectively is 82.3%,73.9%.Looked from the pollution structure,the Beiru River basin mainly by nonpoint source pollution primarily,the Qingyi River basin by point source pollution primarily.According to nonpoint source pollution load estimate result and domestic and foreign experiences,propose the nonpoint source pollution control prevention measure from the policy, the engineering technology,managed three aspects.