Neal Colin, Neal Margaret, Hill Linda, Wickham Heather
Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, OXON, OX10 8BB, UK.
Sci Total Environ. 2006 May 1;360(1-3):272-89. doi: 10.1016/j.scitotenv.2005.08.040. Epub 2005 Oct 25.
The water quality of the River Cherwell and a tributary of it, the Ray, are described in terms of point and diffuse sources of pollution, for this rural area of the upper Thames Basin. Point sources of pollution dominate at the critical ecological low flow periods of high biological activity. Although the surface geology is predominantly clay, base flow is partly supplied from springs in underlying carbonate-bearing strata, which influences the water quality particularly with regards to calcium and alkalinity. The hydrogeochemistry of the river is outlined and the overall importance of urban point sources even in what would normally be considered to be rural catchments is stressed in relation to the European Unions Water Framework Directive. Issues of phosphorus stripping at sewage treatment works are also considered: such stripping on the Cherwell has reduced phosphorus concentrations by about a factor of two, but this is insufficient for the needs of the Water Framework Directive.
针对泰晤士河上游流域的这片乡村地区，本文从点源污染和非点源污染的角度描述了切尔韦尔河及其支流雷河的水质。在生物活动旺盛的关键生态低流量时期，点源污染占主导地位。尽管地表地质主要为黏土，但基流部分来自下伏含碳酸盐地层的泉水，这对水质产生了影响，尤其是在钙和碱度方面。文中概述了该河流的水文地球化学，并强调了即使在通常被视为农村集水区的地区，城市点源污染对于欧盟水框架指令而言的总体重要性。还考虑了污水处理厂的磷去除问题：切尔韦尔河上的此类去除措施已使磷浓度降低了约一半，但这仍不足以满足水框架指令的要求。
