Swat Model-based Non-point Source Pollution Simulation Research In Dongzhen Watershed

The Dongzhen reservoir is considered to be one of the most important reserviors in Putian city, which has many functions like irrigating, flood protecting, domestic water, industrial water,electricity generating and so on, the water quality not only directly effects the economy and society development of the city but also effects the body-safety of citizens. Non-point pollution is the major cause of water pollution, so studying the non-point pollution of Doingzhen reservoir would have long significance for the protection of this water source. Based on the research at home and abroad, this paper applied Soil and Water Assessment Tool(SWAT) Model to be the primary model, and applied ArcGIS, PCI Geomatic, Matlab and other softwares to be the technology platform, on which spatial and attribute databases were built up, that paved the way for simulating Sub-watershed Division, HRUs, Weather Generation and Agriculture Management; the model was calibrated and verified monthly average of runoff load and yearly average of sediment load with the measured hydrology, atmosphere and sediment data of1999-2002, and the parameters of the study were determined. Each index was up to standard, which would explain that the model was fit to the research. The simulation results showed the load and spatial distribution of sediment, total N and total P, and interpreted the distribution features from three views of sub-watered, land use and slopes, at the same time, with the validated model, three different measures of buffer belt, soil and water conversation measures, returning cultivated land to forests were established to simulate, the simulating results could provide theory basis for Dongzhen watershed non-point source pollution treatment.