Quantifying the Contribution of Agricultural and Urban Non-Point Source Pollutant Loads in Watershed with Urban Agglomeration

Urban agglomeration is a new characteristic of the Chinese urbanization process, and most urban located in same watershed. Thus, non-point source (NPS) pollution, especially pollutants areas, aggravates NPS pollution at watershed scale. Many agricultural studies have been performed scale; however, few provided study framework for estimating an catchment. In this study, integrated approach was proposed by coupling Soil Water Assessment Tool (SWAT), event mean concentration (EMC) method Storm Management Model (SWMM). The Hun-Taizi River watershed, which contains typical northeastern China, chosen as case. results indicated that per unit areas total nitrogen (TN) phosphorus (TP) built-up area simulated EMC were 11.9% 23 times higher than values SWAT. SWAT greatly underestimated nutrient yield area. This could provide guidance water environment management plans considering