太湖山地强降雨事件中不同水体的氮磷负荷分析

Nitrogen and Phosphorus Load Analysis in Different Water Bodies in Intensive Rainfall Events in Mountain Areas of Taihu Basin

夏季暴雨洪水是太湖山区氮磷营养盐流失的主要载体,对强降雨事件中的不同水体农业养分负荷的观测和分析,将有助于更准确地评估农业非点源污染。在台风"麦莎"期间,选择典型山区流域对台风降雨径流过程进行观测。结果表明太湖山地短时强降水事件中,地下径流约占总径流的51%,而对无机氮径流负荷的贡献在80%以上;可溶性总磷在河道径流中的浓度低于在地下水和地表径流中的浓度,显示可溶性磷在汇流过程中被截留,说明可溶性磷的迁移具有流域尺度的迟滞特征。

The storm flood in summer is the main carrier of Nitrogen and phosphorus loss in mountain areas of Taihu basin. In the period of Typhoon Matsa reaching Taihu area, the rainfall runoff process is observed by selecting pilot mountain areas. The results indicate that the ground rainfall runoff is about 51% of total runoff in short term rainfall events and brings above 80% of the contribution of inorganic nitrogen. The dissolved total phosphorus in the river channel runoff is lower than that of ground water runoff and surface runoff, which shows that the dissolved total phosphorus is intercepted in the confluence process. The dissolved total phosphorus is of hysteresis characteristics under the basin scale.