Non-point Source Pollution Characteristics And Contribution Simulation Research On Fenhe Reservoir Basin

Aiming at the problem of non-point source pollution on water environment, the paper selected Fenhe reservoir basin as the researchful area. Then the NPS pollution model of Fenhe reservoir was constructed b y researc hing the mec hanis m of NPS pollution. Us ing "3S" technology, spatial interpolation tec hnology and vis ualization technology, the data was extracted and handled; the bas in was discretized. Then Calibration and validation of the model was processed based on measured data. Through the quantitative study of NPS pollution load, the spatial-temporal distribution of NPS pollution and the critic al pollution area was revealed. At the same time, the contribution of the different pollution sources, rivers and land us e types in the bas in was determined. At last, three simulation scenarios, namely fertilizer rate, buffer strip and fertilizer way, were set in order to reflect the influence for NPS load becaus e of their changes. Then the best measures of controlling NPS pollution were explored.This study c an provide academic guide and technologic al uphold for NPS management of Fenhe reservoir. The primary achievement as follows:(1) The model of NPS pollution was established : By rearching the mechanis m of NPS pollution, namely the formation of rainfall runoff, runoff scour and soil eros ion, sediment and nitrogen- phosphorus losses, the model of NPS pollution was set up. It incorporates three portions: hydrologic, sediment and pollutant loss.(2) The bas ic information was processed: Us ing "3S" technology, spatial interpolation tec hnology and vis ualization tec hnology, the spatial data and attribute data was fetched and handled. Then spatial databank and attribute databank of Fenhe res ervoir bas in was built. At the same time, the bas in was discretized by dividing of sub-basin and hydrological response units.(3) The parameters were calibrated and the model was validated: By SUFI-2 algorithm, the parameters were calibrated and the model was validated based on meas ured data of hydrologic al s ite. The results showed that the established model had good applicability for Fenhe reservoir basin.(4) The characteristics and contribution of non-point source pollution were analys is ed : Through s imulating runoff, sediment, nitrogen and phosphorus pollution load of Fenhe reservoir bas in from 2000 to 2013, the spatial-temporal distribution and contribution of non-point source pollution load was analys ised. The res ults showed that the NPS pollution load had a signific ant interannual changes and the load was higher from June to October than others months of each year. It varied cons iderably among eac h sub-bas in. The northwest of Lan country and southeast of Jingle county were the critical area whic h s hould control the nitrogen and phosphorus load. The environmental background values and fertilizer runoff had bigger contribution than the livestock breeding and sewage for NPS pollution load of Fenhe bas in. The nitrogen and phosphorus load of each river had large otherness. As the main storage river, Nitrogen and phosphorus load of Fenhe River(LouFan section) was the largest. Among the tributary rivers, Lanhe River was the largest. The NPS pollution load of forest land, meadow, cultivated land and res idence was different. The NPS pollution load of cultivated land was smalles t; The NPS pollution load of forest land was largest; The NPS pollution load of meadow and Residence were between forest land and cultivated land.(5) Different s ituations were analys ised: Three s imulation scenarios, namely fertilizer rate, b uffer strip and fertilizer way, were set in order to reflect the influenc e for NPS load because of their changes. The res ults showed that reduc ing chemical fertilizer, setting buffer strip and deep fertilizer were benefic ial to reduc e the NPS pollution load. And the reduc ed proportion of setting buffer strip was largest. It manifested that inc reas ing the grass coverage and conc edeing the land to forestry were the most effective meas ures to control the NPS load of Fenhe reservoir basin.