Loads Of Non-point Sources Nitrogen And Phosphorus Imported To The Three Gorges Reservoir From Upper Basin Above Cuntan Of The Yangtze River

Nitrogen and phosphorus are the main elements of a body of water eutrophication. With the formation of the Three Gorges reservoir, the potential water eutrophication become the focus of attention. With the point source pollution is being controlled, the non-point sources of nitrogen and phosphorus input into the Three Gorges Reservoir will be a major threat to the potential occurrence of eutrophication.To control the non-point source pollution effectively and eliminate the threat of water eutrophication in the Three Gorges Reservoir, it is a key that make the non-point sources of nitrogen, phosphorus quantitative, and understand their change laws. In this paper, by the Geographic Information System (GIS) and the Remote Sensing (RS) technology, the non-point source pollution load model from range of upper watershed of Cuntan section of the Yangtze river has been established on the basis of the SLURP model and the Export Coefficient Approach. The SLURP model is a distributed hydrological model based on digital elevation (DEM) and land cover / land use types of remote sensing data (NOAA/AVHRR data), it usually fit in a large watershed. The Export Coefficient Approach also fit in large watershed, and it is on the basis of study cells of land use types. After the model established, it would be used to simulate and analyze the non-point sources of nitrogen and phosphorus pollutant load changes, which input to the Three Gorges Reservoir from the upper watershed. And then, by the British Meteorological Bureau Hadley Center'future global meteorological data, use the established model to explore how the climate and land use changes impact on importation of non-point source of nitrogen and phosphorus load in the Three Gorges Reservoir.Use the established model to calculate the non-point source TN,TP annual load from upper watershed of Cuntan section in the period from 1996 to 2002. To the non-point source TN load, except the calculated relative errors in 1996 and 1998 are larger (-27.89% and 30.09% respectively), the relative errors in the other years are very small. To the non-point source TP load, except the calculated relative errors in 1996 and 2001 are larger (-40.15% and 64.33%, respectively), the relative errors in the other years are also very small. As a whole, the model has a better simulation result.Use the established model to calculate and analyze the change situation of the non-point sources of nitrogen and phosphorus pollutant load in the watershed outlet past...