Abstract：At present, many countries face severe non-point source pollution, in which the load of nitrogen pollution is still the key issues of water resource and environmental governance. The load of nitrogen pollution and its spatial and temporal distribution were simulated and analyzed by using SWAT model with the topography, land use, climate condition and other factors, which will be great significant for non-point source pollution control. Based on basic data collection of Puhe River Basin of Shenyang City, Liaoning Province, simulation research databases was built by SWAT model coupled with GIS. The whole basin was divided into 23 sub-basins and 215 hydrological response units according to water type distribution of Puhe. Nitrogen forms, contribution ratio of nitrogen pollution load, critical nitrogen pollution areas and the nitrogen pollution distribution of spatial and temporal were simulated. Results showed that: 1) The nitrogen mainly exists by forms of organic nitrogen, NH+4 -N, NO-3 -N, NO-2 -N in water, in which that of NO-3 -N is maximum. 2) On the temporal scale, the content of TN fluctuated monthly, moreover, TN loss was hysteretic significantly. 3) At the spatial scales, organic nitrogen and NO-3 -N in the basin diffused from northeast to southwest direction. The nitrogen content of upstream and midstream was higher than the downstream region. In addition, No. 1 sub-basin is the key nitrogen pollution area in the basin, No. 3, 9 and 10 sub-basin are the secondary nitrogen pollution areas. The TNcontribution region mainly located at the area from basin outlet to the water of Majiawopeng.
2013, Vol. 11 
