Abstract:
The total nitrogen and total phosphorus loss were evaluated in the study by using a calibrated Soil and Water Assessment Tool (SWAT) model under seven nutrient application scenarios.The results showed that the total nitrogen losses reached about 1 427 t per year in the research region but can be decreased greatly by about thirty percent when the experts′ suggested nitrogen input scenarios applied. In contrast, the loss of total phosphorus was not so seriously in the region with about 0.7 t loss per year and little can be decreased under the six improved scenarios. It indicated controlling the nitrogen loss in the region was urgently needed in the lakeshore region of Miyun Reservoir. And the critical areas for nutrient control were located at southeast Fengjiayu town, central and eastern, western of Taishitun town, central and eastern of Bulaotun town, midwest of Xinchengzi town; middle and lower of Baimaguan reach, upstream of Qingshui reach, middle and lower of Andamu reach, which have high rate of nitrogen application and nitrogen loss.
