Department of Environmental and Geographical Sciences, Manchester Metropolitan University, Manchester M1 5GD, UK.
Sci Total Environ. 2010 Jan 15;408(4):841-55. doi: 10.1016/j.scitotenv.2009.10.041. Epub 2009 Nov 18.
This paper presents information on the spatial and seasonal patterns of river water chemistry at approximately 800 sites in North West England based on data from the Environment Agency regional monitoring programme. Within a GIS framework, the linkages between average water chemistry (pH, sulphate, base cations, nutrients and metals) catchment characteristics (topography, land cover, soil hydrology, base flow index and geology), rainfall, deposition chemistry and geo-spatial information on discharge consents (point sources) are examined. Water quality maps reveal that there is a clear distinction between the uplands and lowlands. Upland waters are acidic and have low concentrations of base cations, explained by background geological sources and land cover. Localised high concentrations of metals occur in areas of the Cumbrian Fells which are subjected to mining effluent inputs. Nutrient concentrations are low in the uplands with the exception sites receiving effluent inputs from rural point sources. In the lowlands, both past and present human activities have a major impact on river water chemistry, especially in the urban and industrial heartlands of Greater Manchester, south Lancashire and Merseyside. Over 40% of the sites have average orthophosphate concentrations >0.1mg-Pl(-1). Results suggest that the dominant control on orthophosphate concentrations is point source contributions from sewage effluent inputs. Diffuse agricultural sources are also important, although this influence is masked by the impact of point sources. Average nitrate concentrations are linked to the coverage of arable land, although sewage effluent inputs have a significant effect on nitrate concentrations. Metal concentrations in the lowlands are linked to diffuse and point sources. The study demonstrates that point sources, as well as diffuse sources, need to be considered when targeting measures for the effective reduction in river nutrient concentrations. This issue is clearly important with regards to the European Union Water Framework Directive, eutrophication and river water quality.
本论文基于环境署区域监测计划的数据，提供了英格兰西北部约 800 个地点的河流水化学的空间和季节性模式信息。在 GIS 框架内，考察了平均水质（pH 值、硫酸盐、基础阳离子、养分和金属）与流域特征（地形、土地覆盖、土壤水文学、基流指数和地质）、降雨、沉积化学以及排放许可证的地理空间信息之间的联系（点源）。水质图表明，高地和低地之间有明显的区别。高地水呈酸性，基础阳离子浓度低，这可以用背景地质源和土地覆盖来解释。在坎布里亚丘陵地区，由于采矿废水的输入，局部金属浓度较高。除了接收农村点源废水输入的地点外，高地上的养分浓度较低。在低地，过去和现在的人类活动都对河流水化学产生了重大影响，特别是在大曼彻斯特、南兰开夏和默西塞德的城市和工业中心地带。超过 40%的地点的平均正磷酸盐浓度>0.1mg-Pl(-1)。结果表明，正磷酸盐浓度的主要控制因素是来自污水排放的点源贡献。尽管点源的影响掩盖了这种影响，但农业的扩散源也很重要。平均硝酸盐浓度与耕地的覆盖面积有关，尽管污水排放的输入对硝酸盐浓度有显著影响。低地的金属浓度与扩散源和点源有关。该研究表明，在针对有效降低河流水体营养物浓度的措施时，不仅要考虑点源，还要考虑扩散源。这一问题在欧盟水框架指令、富营养化和河流水质方面显然很重要。
