Bathing Waters ZOI Catchments

Bathing water zones of influence (ZOI) are defined as an area where if heavy rainfall occurs may lead to surface water runoff causing a reduction in water quality at a designated bathing water. These Bathing waters are often impacted by either surface water or streams & rivers. Not all bathing waters have zones of influence, very small catchments or run off areas have not been defined. They were originally designed to be presented on PDF maps for use in bathing water profiles as per the bathing water directive 2006/7/EC in 2012 and therefore of low resolution. The polygons were derived from a range of sources from digital elevation models to being manually digitised. They are annual updated with any changes to the designated bathing water inventory. Attribution statement: © Environment Agency copyright and/or database right 2015. All rights reserved.沐浴水域影响区（Bathing water zones of influence, ZOI）指的是一旦发生强降雨，便可能产生地表径流，进而导致指定沐浴水域水质下降的区域。此类沐浴水域通常受地表水、溪流或河流的影响。并非所有沐浴水域都设有影响区，集水区过小或径流区域未被划定。2012年，依据欧盟《2006/7/EC沐浴水指令》的相关要求，此类影响区最初被设计为以PDF地图形式呈现，用于沐浴水域概况文档，因此分辨率较低。该类多边形数据集源自多种数据源，涵盖从数字高程模型到手动数字化矢量化的各类手段。该数据集会根据指定沐浴水域名录的变更情况每年更新一次。署名声明：© 环境署（Environment Agency）2015年版权及数据库权利保留。保留所有权利。