Spatial distribution of non-point source pollution and its relation to land use structure in Muling River watershed, Sanjiang Plain

It is important to better understand the spatial distribution of non-point source pollution and related influencing factors in China. On the bases of field sampling, using GIS techniques, this paper analyzed the spatial characteristics of non-point pollution and its relation to land use structure, taking Muling river sub-basin in Sanjiang Plain as the study area. The result shows that the value of TSS, TN, and TP exceed the country criteria and the discrepancy in space is little. In the sub-basin which are controlled mainly by a single land use type, surface water quality of woodland controlled sub-basin is better than that of cropland controlled sub-basin. The concentration of pollutants in combined structure (cropland, woodland and grassland) is highest in three land use structures. This may be due to the complex surface background and other point source pollution in this study area.