Permeability Dataset for Great Britain (Artificial Deposits)

The data comprises GIS layers representing the permeability of artificial deposits for Great Britain. The permeability data has been derived from DiGMap-GB (Digital Geological Map Data of Great Britain), and therefore reflects the scale of DiGMap-GB. For the majority of the Great Britain, the scale is 1:50,000. The data is updated annually, or after a major new release of DiGMap-GB. The permeability data describes the fresh water flow through these deposits and the ability of a lithostratigraphical unit to transmit water. Maximum and minimum permeability indices are given for each geological unit to indicate the range in permeability likely to be encountered and the predominant flow mechanism (fracture or intergranular). Neither of the assigned values takes into account the thickness of either the unsaturated or saturated part of the lithostratigraphical unit. The data can be used freely internally, but is licensed for commercial use. It is best displayed using a desktop GIS, and is available in vector format as ESRI shapefiles and MapInfo TAB files.本数据集包含用于大不列颠的人工堆积层渗透性地理信息系统（GIS，Geographic Information System）图层。该渗透性数据源自DiGMap-GB（英国数字地质地图数据，Digital Geological Map Data of Great Britain），因此其比例尺与DiGMap-GB保持一致。大不列颠境内绝大多数区域的比例尺为1:50000。本数据集每年更新一次，或在DiGMap-GB发布重大新版后同步更新。该渗透性数据用于描述淡水穿过此类堆积层的流动过程，以及岩石地层单位的导水能力。每个地质单元均配有渗透性最大值与最小值指标，用以标注实际可能出现的渗透性取值范围，以及主要的水流运移机制（裂隙型或粒间型）。上述两项赋值均未考虑岩石地层单元非饱和带或饱和带的厚度。本数据集可免费内部使用，但商业使用需获得授权许可。最佳展示方式为使用桌面地理信息系统（GIS），数据以矢量格式提供，格式包括ESRI形状文件（ESRI shapefiles）与MapInfo TAB文件。