红枫湖流域非点源污染时空分布及管理措施

Spatiotemporal distribution and control measures of non-point source pollution in the Hongfeng Lake Basin

为分析红枫湖流域非点源污染状况及非点源污染防控措施效果,利用该流域典型子流域的水量和水质数据对SWAT模型的径流和水质参数进行率定和验证,采用验证后的模型模拟了2001—2015年流域氨氮、总氮和总磷的时空分布特征,并分析了不同管理措施对非点源污染的削减效果。结果表明:SWAT模型在红枫湖流域具有良好的适用性;氨氮、总氮、总磷负荷主要集中在4—9月,分别占全年负荷的88.49%、83.74%和97.36%,西南部和东北部的子流域氮磷流失较大,是非点源污染的关键源区;化肥削减、退耕还林还草措施能有效削减非点源污染,尤其是总磷污染,实施综合管理措施对氮磷污染削减的效果更佳。

In order to investigate the situation of non-point source pollution in the Hongfeng Lake Basin,as well as the effects of prevention and control measures,the water quantity and water quality data of a typical sub-basin were used to calibrate and validate the water quantity and water quality parameters of the SWAT model.The validated SWAT model was used to simulate the spatiotemporal distribution of ammonia nitrogen,total nitrogen,and total phosphorus from 2001 to 2015 and investigate the effects of different measures on the control of non-point source pollution.The results show that the SWAT model has good applicability in the Hongfeng Lake Basin.The ammonia nitrogen,total nitrogen,and total phosphorus loads are mainly concentrated from April to September,accounting for 88.49%,83.74%,and 97.36%,respectively,of the annual loads.The southwest and northeast sub-basins with large losses of nitrogen and phosphorus are key source areas of non-point source pollution.Measures such as fertilizer reduction and conversion of farmlands to forests and grasslands can effectively reduce the non-point source pollution,in particular,the total phosphorus pollution.The implementation of comprehensive management measures has a better effect in reducing nitrogen and phosphorus pollution.