Ground conditions in central Manchester and Salford : the use of the 3D geoscientific model as a basis for decision support in the built environment

In the urban environment, site investigation studies provide a wealth of information about the ground conditions of the shallow subsurface. However, from the developers’ perspective, there is generally little incentive to integrate this information beyond the boundaries of the development site. By taking a more holistic view and combining knowledge of the near-surface geology with information on former land use and the groundwater regime across a wider area, it is possible to predict geological scenarios that may better inform ground investigation and reclamation strategies. As part of its urban research programme, the British Geological Survey has integrated its data holdings across 75 km2 of central Manchester and Salford. The information has been used to develop an integrated 3D model of the shallow subsurface. By exporting the elements of the model to a Geographical Information System (GIS), there is the capability to produce on demand bespoke maps, crosssections and other visualisation aids, relevant to regional planning and site appraisal. The value of such a system is illustrated by reference to five topic areas (geology, geotechnical engineering, hydrogeology, geochemistry and land use). A series of thematic maps illustrates the range of outputs. The approach provides a means of identifying potential problems and opportunities at an early stage in any proposed development and, if implemented over a wider area, it could assist in designing site investigation strategies and reduce costs by ensuring a more focused approach to development planning.