User guide : Aquifer Productivity (Scotland) GIS Datasets. Version 2

This report describes a revised version (Version 2) of the aquifer productivity (Scotland) datasets produced by the British Geological Survey (BGS). There are two maps: bedrock aquifer productivity and superficial deposits aquifer productivity. Version 1 of these datasets was produced in 2004. Version 2 uses updated geological linework and a slightly modified methodology. The aquifer productivity maps describe the potential of aquifers across Scotland to sustain various levels of borehole water supply, and the dominant groundwater flow types in each aquifer. The bedrock aquifer productivity map has five aquifer productivity classes (very high, high, moderate, low and very low); and three groundwater flow categories (significant intergranular flow; mixed fracture/intergranular flow; and fracture flow). The superficial deposits productivity map has four productivity classes (high; moderate to high; moderate; and a category to signify that a deposit is ‘not a significant aquifer’). All superficial deposits aquifers in Scotland are assumed to have primarily intergranular groundwater flow. The aquifer productivity maps are a tool to indicate the location and productivity of aquifers across Scotland. They have been used to help characterise groundwater bodies as required by the Water Framework Directive, and may have several other uses, including in policy analysis and development; to prioritise aquifer and site investigations; to inform planning decisions; and to improve awareness of groundwater in general. The complexity and heterogeneity of geological formations means that the maps are only a guide. They are designed to be used at a scale of 1:100,000, and not to assess aquifer conditions at a single point