Global NEWS (Global Nutrient Export from WaterSheds) is an international modeling effort with few Chinese application cases, and this essay applied the model with modifications to Beijiang River Basin, one of the three main sub-basins of the Pearl River, in order to estimate the river basin-level export of multiple nutrient elements and elemental forms from land sources within the river basin to river mouths. A reliable environmental database of Beijiang River Basin was established by literature review and statistics collection, and with the help of ArcGIS technology. Model calibration and verification showed that the Nash-Sutcliffe model efficiency was 0.61 on DIN (Dissolved Inorganic Nitrogen) loads (t/a) exported at the basin mouth, indicating that the model performs reasonably well for DIN. Modelling results show that 1) in 2010, dissolved nitrogen exports (load) from Beijiang River Basin was 37.5 thousand t/a, which was 9.27% higher than that in 2000, with DIN accounting for 83.51% and DON (Dissolved Organic Nitrogen) accounting for 16.49%. 2) In 2010, dissolved phosphorus exports (load) from Beijiang River Basin was 46.3 thousand t/a, which was 30.05% higher than that in 2000, and contained 86.21% of DIP (dissolved inorganic phosphorus) and 13.79% of DOP (dissolved organic phosphorus). 3) Spatially, nutrients exports (load) from Sui River Basin, one of the downstream sub-basins, and nutrients exports (load) from Lian River Basin, one of the midstream sub-basins, were relatively higher than those from other sub-basins, indicating the necessity of controlling nutrient pollution in the two sub-basins. 4) Atmospheric nitrogen deposition was the major source of DIN export load, followed by synthetic fertilizer and biological nitrogen fixation, while animal wastewater discharging was the major source of DIP export load, followed by synthetic fertilizer. The results also show that the NEWS model is applicable to China’s small-to-medium river basins.
