In the first case study presented here, a geographic information system (GIS) is used to create a groundwater vulnerability map of the Midlands and northwest of England by overlaying regional information on the solid geology, Quaternary drift cover and soil cover. The map reveals that areas of extreme and high groundwater vulnerability occur in the vicinities of Birmingham, Liverpool and Manchester.
In the second study, a GIS is used to create a groundwater vulnerability map for southeast England and to combine this information with results from a routing model for the transport of hazardous aqueous waste within the region. The routing mode utilizes an accident-minimizing scenario and expresses the potential pollution threat to groundwater as the number of tanker-kilometers directed over each groundwater vulnerability class.
It is concluded that a GIS methodology is very suitable for groundwater vulnerability mapping, providing an ability to integrate multiple layers of information and to derive additional information, for example on pollution risks. A GIS also allows flexibility in the revision of maps should existing information become obsolete, or revision of the groundwater vulnerability classification scheme be necessary.