Mapping groundwater vulnerability in Scotland: a new approach for the Water Framework Directive

Abstract

A new methodology for groundwater vulnerability assessment has been devised for Scotland to meet the requirements of the Water Framework Directive. Using the methodology, a new GIS-based map of groundwater vulnerability has been produced, at a working scale of 1:100 000. The map is being used by the Scottish Environment Protection Agency (SEPA) to help characterize and assess risk to groundwater bodies. The methodology assesses the vulnerability of groundwater in the uppermost aquifer to the vertical downward movement of a non-specific contaminant from the ground surface. It considers the intrinsic properties of the pathway between the ground surface and the water table. The key difference from previous vulnerability maps in Scotland and the rest of the UK is that the new method assesses vulnerability in all aquifers regardless of resource potential. This reflects the diverse environmental objectives for groundwater bodies under the Water Framework Directive. This approach provides the flexibility to combine the groundwater vulnerability map with maps of pressures, groundwater resources or other groundwater-related receptors, as required