福建盆谷型农业小流域氮磷流失模式分析——以漳州市五川流域为例

Nutrient export patterns from an agricultural catchment of basin hill in Fujian province——case as Wuchuan subwatershed,Zhangzhou city

利用现场连续采样监测分析和模型模拟确定了福建盆谷型农业小流域不同水文时期农业氮磷迁移和流失的模式和关键源区.2002年每月基流时期的水质采样分析表明:可溶态氮从流域的源头区到流域的出口区表现为上升的趋势,但是可溶态磷却表现为下降的趋势.由于小流域内部土壤空间的物理和化学性质的分异,流域源头区是可溶态磷的关键源区,而流域的出口区是可溶态氮的关键源区.通过用实测数据检验后的agri-cultural non-point source model模型,确定了流域两侧的坡地区是可溶态氮磷流失和迁移的关键源区.

The sources and magnitude of agricultural nutrient export from a catchment of basin hill of Fujian province are not identical. Nitrogen and phosphorus export patterns and their critical source areas （CSAs） were identified in a 1.74 km^2 mountainous agricultural catchment. During baseflow the concentration of soluble nitrogen increased downstream, while dissolved phosphate concentration decreased downstream from the uppermost site to the outlet. The upstream area-segment 1 is a CSA for dissolved phosphate export, but the outlet areas-segments 6, 7 are CSAs for soluble nitrogen loss during baseflow. Two precipitation events with a similar precipitation magnitude but different duration were used to test the agricultural non-point source （AGNPS） model. During storm flow, CSAs for both dissolved nitrogen and phosphorus, defined through the AGNPS model tested, are side-slope areas where citrus has been planted.