浦阳江流域(浦江县段)面源污染模型估算及河流生态缓冲带重点区域识别

以浦阳江流域(浦江县段)为研究区，从流域面源污染空间特征入手，提出浦阳江流域岸边带建设的重点区域。采用DPeRS面源污染负荷估算模型，具体分析了2018年浦阳江流域面源污染负荷空间分布特征，并采用面向对象方法提取了岸线和河流生态缓冲带土地覆盖类型，以汇水区为单元，结合面源污染估算结果识别了浦阳江流域河流生态缓冲带重点区。结果表明：浦阳江流域中部和中北部地区面源污染排放负荷较高，面源污染入河负荷高值区主要集中于中下游地区；该流域31个汇水区中，TN和NH₄⁺-N重点汇水区有17个，主要分布在流域的中部和东北部；TP和COD重点汇水区有12个，集中分布于流域中部；浦阳江流域河流生态缓冲带范围内，植被类型和非植被类型面积占比分别为65.49%和34.51%，其中耕地面积占比29.36%，建筑用地占比11.89%；综合浦阳江流域面源污染重点汇水区和河流生态缓冲带现状遥感提取结果，筛选出的重点区包括下游地区的7号汇水区和中游地区的18~25号汇水区所在的河流生态缓冲带。今后，可针对其重点区域设计生态防护工程，也应结合源头减量、过程拦截、末端消纳与资源循环利用的防控策略，综合削减面源污染物入河量。

Estimation of non-point source pollution model in Puyang River Basin(Pujiang County Section) and identification of key areas of riparian ecological buffer zone

As the last line of defense for controlling non-point source pollution into the water body, the important ecological function of riparian zone is recognized by scholars. In particular, the choice of the spatial location of the ecological engineering for riparian zone plays a key role in improving the water quality of the river basin. This article taking Puyang River Basin (Pujiang County Section) as the research area extracts the key areas for the construction of the riparian ecological buffer zone in Puyang River Basin from the spatial characteristics of non-point source pollution in the river basin. Specifically, the article analyzes the spatial distribution characteristics of the non-point source pollution load in the Puyang River Basin in 2018 using the DPeRS non-point source pollution load estimation model, and extracts the land cover types of the shoreline and riparian ecological buffer zone with object-oriented method. Meanwhile, the key areas of riparian ecological buffer zone in the Puyang River Basin is identified with the results of non-point source pollution estimation regarding catchment area as unit. The results show that the central and northern parts of the Puyang River Basin have high non-point source pollution discharge loads, and high-value areas of non-point source pollution loads entering into river are mainly concentrated in the middle and lower reaches of the river basin. Among the 31 catchment areas in the river basin, there are 17 key catchment areas of non-point source pollution of TN and NH4+-N mainly distributed in the middle and northeast of the river basin. And 12 key catchment areas of non-point source pollution of TP and COD are concentrated in the central river basin. Within the riparian ecological buffer zone of the Puyang River Basin, the area ratio of vegetation types and non-vegetation types are 65.49% and 34.51%, respectively, among which cultivated land is 29.36% and construction land is 11.89%. Based on extraction results of the current situation of the key catchment areas and riparian ecological buffer zones of non-point source pollution in the Puyang River Basin with remote sensing, the selected key areas are including the buffer zone where the No. 7 catchment area in the downstream area and the No. 18~25 catchment areas in the middle reaches are located. Therefore, the ecological protection project can be designed for key riverbank buffer zones, and the prevention and control strategies of source reduction, process interception, end consumption and resource recycling should also be combined to comprehensively reduce the amount of non-point source pollutants into the river.