| description:
|
The 5km Hex GS Collapsible Deposits dataset shows a generalised view of the GeoSure Collapsible Deposits v8 dataset to a hexagonal grid resolution of 64.95km coverage area (side length of 5km). This dataset indicates areas of potential ground movement in a helpful and user-friendly format. The rating is based on a highest level of susceptibility identified within that Hex area: Low (1), Moderate (2), Significant (3). Areas of localised significant rating are also indicated. The summarising process via spatial statistics at this scale may lead to under or over estimation of the extent of a hazard.
The supporting GeoSure reports can help inform planning decisions and indicate causes of subsidence. The reports can help inform planning decisions and indicate causes of subsidence. The Collapsible Ground dataset provides an assessment of the potential for a geological deposit to collapse (to subside rapidly) as a consequence of a metastable microfabric in loessic material. Such metastable material is prone to collapse when it is loaded (as by construction of a building, for example) and then saturated by water (as by rising groundwater, for example). Collapse may cause damage to overlying property. The methodology is based on the BGS Digital Map (DiGMapGB-50) and expert knowledge of the origin and behaviour of the formations so defined. It provides complete coverage of Great Britain, subject to revision in line with changes in DiGMapGB lithology codes and methodological improvements. |