Studies On The Agricultural Non-point Pollution And Its Control Measures Of Yitong River Basin

In the course of the land use or human production activities, non-point source pollutionforms through a continuous or multiple point pollution within a small area discharge, whichproduce waste water, waste gas and solid waste. Non-point source pollutants gradually releaseinto the air, soil and water, causing, environment quality decrease and ecological destruction.Agricultural non-point pollution sources include rural living rubbish, the livestockfarming waste and the waste of agricultural production activities. All kinds of pollutantsrelease into the river water under various physical, chemical, and biological functions, whichmake the non-point pollution get worse. Yitong River is an important branch of the SecondSonghua river basin and the area is about8840km2, which water quality is poor. In recentyears with the development of the soil and water loss and the chemical fertilizer and pesticideutilization, the farmland waster discharge into the Yitong River and the water pollution isgetting more and more serious.The study investigated the information of the agricultural non-point pollution of theYitong River basin. The study calculated the pollution created by the livestock and poultry,the rural runoff pollution, and the COD and ammonia nitrogen pollution discharged by therural wastewater, applying the discharge coefficient method, SCS model and emissioncoefficient method. The results show that the output of COD and ammonia nitrogen fromraising livestock and poultry within the basin were the largest pollution source, which wereaccount for51.77%and64.35%, respectively; and the following pollution sources were therural runoff source and raising livestock and poultry pollutant sources. The most output ofCOD and ammonia nitrogen pollution released into the river were produced by the ruralrunoff pollution, and followed by the large-scale livestock farming and rural living pollutions.Statistical results show that the biggest quantity of COD and ammonia nitrogen produce andits discharging into the river is the Sihua Dams to the estuary segment.Aiming at the main influence factors for the agricultural non-point pollution of theYitong River basin, the rational adjusting agricultural structure and layout, the development ofecological agriculture were put forward as the main management measures controlling thenon-point pollution. The control measures of pesticide and fertilizer utilization, runoffpollution, livestock farming pollution were also the main treatments as well as the publicenvironmental protection consciousness.Through the study, this paper reveals the Yitong River basin agricultural non-pointpollution characteristics, and according to the actual situation proposed effective pollutionreduction technology and control countermeasures.