Long-Term Impacts of Land Use Change on Non-Point Source Pollution in the Dagujia River Watershed of Shandong Peninsula

Non-Point Source (NPS) pollution in coastal zone are of increasing concern among water environment managers and planners worldwide. In this paper, the long-term impacts of land use change on temporal-spatial variations of runoff, total nitrogen (TN) and total phosphorus (TP) in Dagujia River watershed was studied by jointly using hydrological analysis, SCS-CN method and Pollutant Coefficients Method based on GIS spatial analysis techniques. The results suggest that the runoff volume, TN and TP loads in the entire watershed have significantly increased from 1980 to 2009 and there are great spatial differences among three sub-basins. In addition, the residential area, industrial area and agricultural lands in the watershed are associated with more nutrient loads, whereas forest and grass/pasture with less loads. The information derived from this study can provide good decision supports for coastal land use planning and water environment improvement.