基于LAM模型的多干扰特征河流磷污染源解析

针对高强度复杂人类干扰河流磷来源难以定量解析的问题,构建基于流量与污染物浓度关系模式的污染源解析模型,定量分析多干扰类型河流磷的点源和非点源负荷与时间贡献。以滇池流域的源头河流、水库干扰河流、水库-调水复合干扰河流等为例,采用LAM源解析模型建立了河流磷浓度与流量的响应关系,分析了主要河流磷的源贡献结构与时空分布特征。结果表明:2018年非点源是滇池主要入湖河流磷的主要贡献源,非点源负荷占比为53%~100%,汛期与全年差异较小;从污染源主导时间看,点源是宝象河和盘龙江大花桥-德胜桥段时间占比最高的污染源,表明低流量期间点源控制对改善水质仍然具有十分重要的意义。研究结果可为我国多种人为干扰类型河流的磷污染源解析提供方法借鉴与指导。

SOURCE IDENTIFICATION OF PHOSPHORUS IN VARIOUS DISTURBED RIVERS BASED ON LAM MODEL

It is generally difficult to quantify the phosphorus source of high-intensity and complex human interference rivers,so a pollution source apportionment model based on the relationship between flow and pollutant concentration was constructed to identify the point source and non-point source load and time contribution of river phosphorus.Taking the upstream river,river with reservoir and river with both reservoir and water transfer project in the Lake Dianchi Basin as the objects,the response relationship between river phosphorus concentration and flow was established by LAM model,and the source contribution structure and spatiotemporal distribution of phosphorus in main rivers were analyzed.Results showed that non-point source was the major source of phosphorus in the main rivers entering the Dianchi Lake in 2018,and the non-point source load accounted for 53%~100%,with a negligible difference between flood season and all year round;as for the dominant time of pollution sources,point sources account for the highest time proportion in the Baoxiang River and the Dahuaqiao-Deshengqiao section of the Panlong River,indicating that point source control was still of great significance to improve water quality in low flow seasons.The results can provide reference and guidance for identifying phosphorus pollution sources in many human disturbance rivers in China.