SWAT模型点源输入识别方法研究--以鞍山市南沙河流域为例

IDENTIFICATION OF THE POINT SOURCE LOAD INPUT FOR THE SWAT MODEL:A CASE STUDY IN THE NANSHA RIVER IN ANSHAN CITY

点源污染的划分和核定是正确估算流域非点源污染负荷的重要工作.我国城市地区往往缺乏可靠的点源入河数据,因此,在SWAT模型的应用中需要根据有限资料进行点源污染输入识别,以确保模拟结果的正确性.本文以鞍山市南沙河流域为例构建了非点源SWAT模型,探讨了点源输入识别中总量估算、时空分配、营养物质形态划分和迁移过程中降解估算等4个方面的问题和处理方法,评估了单位负荷法、现场试验法和统计数据法等3种点源负荷总量估算方法的优劣.结果表明,统计数据法以实际统计资料为依据,能较好反映点源负荷的年际变化,估算结果较好;点源对总氮和总磷的贡献率分别达到了79%和82.5%,是南沙河流域的主要污染源.因此点源控制是改善南沙河流域水质状况的首选措施.

Proper input of point source discharge load is the basis of non-point source pollution estimation using SWAT model.However,most of urban areas lack measured data and it is necessary to identify point source input based on limited information in the application of SWAT model.In order to investigate approaches for the estimation of load,temporal and spatial distribution,nutrient forms division and degradation of point source discharge,SWAT model in the Nansha River was developed,and three discharge estimation methods were evaluated.Data showed that statistical method,based on observed data,performed very well on the estimation of point source discharge;point source was found to be the major source of pollution for the Nansha River basin,and point source control should be the most effective measure to improve water quality.