基于SWAT的柴河水库流域非点源污染识别与评价

IDENTIFICATION AND ASSESSMENT OF NON-POINT SOURCE POLLUTION IN THE CHAIHE RESERVOIR CATCHMENT USING SWAT

基于SWAT模型,以山区饮用水水源控制单元——柴河水库流域为例,分析了流域非点源污染的主要来源和构成,并就非点源污染模型识别和输入方法进行了讨论.在径流和泥沙过程模拟的基础上,对流域非点源污染进行了模拟识别和评价.结果表明,SWAT模型对柴河水库流域的径流、泥沙和水质模拟适应性较好,趋势匹配较理想,但部分年份模拟峰值存在一定偏差.空间分析表明柴河水库流域非点源污染表现出显著的空间分布特征,氮和磷的产生主要集中于河流中下游农业生产区域;贡献率分析表明化肥施用和畜禽养殖污染对氮、磷贡献较大,是流域非点源污染控制的重点.

Soil and water assessment tool（SWAT） was selected to simulate runoff,sediment and non-point source pollution in the Chaihe reservoir watershed.The main sources of non-point source pollution were analyzed and input method was discussed.After the runoff and sediment were validated,non-point source pollution in the watershed was modeled and evaluated.Data showed that SWAT model performed satisfactorily in the study area for simulated runoff,sediment and water quality.The trends matched well and peaks fluctuated between observed and simulated values.Spatial analysis revealed that non-point source pollution in the study area was spatially-distributed.TN and TP load was found to be concentrated in the middle and downstream parts of the watershed,critical areas with strong agricultural activities.Contribution rate analysis showed that fertilizer application and livestock were major contributors for TN and TP load,which should be the key factors for non-point source pollution.