基于通量贡献法的河流断面污染定量溯源

Pollutant Quantitative Tracing of River Water Quality Section Based on the Flux Contribution Method

控制单元水质目标管理背景下,需要对影响河湖水质的污染物进行溯源。以湟水河流域为例,将污染源按照点源和非点源进行分类量化,基于污染物通量贡献溯源方法,利用清单分析法、输出系数法对点源和非点源的氨氮、TP入河量及其贡献率进行核算,根据贡献率识别主要点源类型及其位置,并在乡镇尺度识别非点源污染热点区、重点污染源种类。结果表明:点源中,污水处理厂和工业源对氨氮的贡献率最大,规模化畜禽养殖场对TP的贡献率最大;点源主要分布在湟水河中游和西宁市城区,且点源在旱季对断面污染物的影响远大于雨季;非点源单元中,湟水河流域一些乡镇的城镇生活源是边墙村断面氨氮的重要来源,湟水河流域中游和上游一些乡镇的非点源对边墙村断面TP有重要影响,其中城镇生活源、农业种植源是TP的重要来源。

In the context of water quality target management,it is necessary to trace the pollution sources that impact the water quality of riv-ers and lakes.Taking the Huangshui River basin as an example,pollution sources were classified and quantified as point sources and non-point sources.Based on the pollutant flux contribution tracing method,inventory analysis and output coefficient method were used to calculate the inflowing loads and contribution rates of ammonia nitrogen(NH3-N)and total phosphorus(TP)from point sources and non-point sources.By identifying the magnitude of contribution rates,the main types and locations of point sources were identified,and the non-point source pollution hotspots and key pollution source types were identified at the town scale.The results show that sewage treatment plants and industrial sources contribute the most to NH3-N,while large-scale livestock and poultry farming sources contribute the most to TP.Point sources are mainly distributed in the middle reaches of the Huangshui River and the main urban area of Xining.Point sources have a signifi-cantly greater impact on pollutant concentrations during the dry season than the rainy season.As for non-point sources,urban domestic sources in certain townships in the Huangshui River Basin are identified as significant contributors to NH3-N at the Bianqiang Village section.Non-point sources from some townships in the middle and upper reaches of the Huangshui River Basin have an important impact on TP at the Bianqiang Village section,with urban domestic sources and agricultural planting sources being important sources of TP.