基于受体模型和控制单元分区的流域污染源解析——以永定河张家口段为例

为识别永定河张家口段水体污染的主要来源并确定流域重点管控行业和优控单元,将受体模型与控制单元分区相结合,建立流域污染源解析方法。结合研究区水系分布、行政区划和数字高程模型(DEM)数据进行控制单元划分,利用聚类分析进行水质和污染源空间特征分析,通过因子分析和绝对主成分-多元线性回归(APCS-MLR)受体模型进行分区污染源识别与贡献率计算。结果表明:永定河张家口段按水质污染程度可分为污染较重的A区(洋河、清水河中下游)和污染较轻的B区(洋河、清水河上游及桑干河);A区受工业点源与面源混合影响,其中工业点源、农业种植贡献率分别为43%、44%;B区主要受面源影响,其中农村生活及旅游、农业种植、畜禽养殖贡献率分别为30%、18%、17%;由污染源空间特征,提出A区的重点管控行业为冶金和食品制造业,B区则为采矿业和食品制造业,确定覆盖阳原县的2、3号,覆盖涿鹿县北部和蔚县北部的5号,覆盖万全区的14号控制单元为面源污染优先防控单元。源解析与控制单元分区相结合的方法可较好地反映水质空间分异特征,提高源解析能力。

Watershed pollution source analysis based on receptor model and control unit division: taking Zhangjiakou section of Yongding River as an example

In order to identify the main sources of water pollution in Zhangjiakou section of the Yongding River, and to determine the key control industries and priority control units of the basin, the receptor model was combined with the control unit division to establish the analysis method of pollution sources in the basin. Based on the water system distribution, administrative divisions and digital elevation model (DEM) data, the study area was divided into 16 control units. Cluster analysis was used to analyze the spatial characteristics of the water quality and pollution sources. Factor analysis and absolute principal component scores-multiple linear regression (APCS-MLR) receptor model were used to identify the source of pollution and calculate the contribution rate. The results showed that, according to the degree of water pollution, the study area could be classified into area A (middle and lower reaches of the Yang River and the Qingshui River) with heavy pollution, and area B (upper reaches of the Yang River and the Qingshui River and the entire Sanggan River) with light pollution. Area A was mainly affected by the mixture of industrial point sources and non-point sources. The contribution rate of industrial point sources was 43%, and that of agricultural plant pollution was 44%. Area B was mainly polluted by non-point sources. The main pollution was sewage from rural life and tourism (30%), agricultural planting (18%), and livestock breeding (17%). According to the spatial characteristics of pollution sources, the key control industries in area A were metallurgical and food manufacturing, and that in area B were mining and food manufacturing. Besides, the control units No.2 and 3 covering Yangyuan County, No.5 covering northern Zhuolu County and northern Yu County, and No.14 covering Wanquan County were identified as priority prevention and control units of source pollution. The research showed that the method combined source analysis with control unit division can reflect the spatial differentiation characteristics of the water quality and improve the source analysis ability.