Methodology
| Name | Category | Description |
|---|---|---|
| Running Sands | Ground Stability | Some rocks can contain loosely packed, sandy layers that can become fluidised by water flowing through them. Such sands can ‘run’, removing support from overlying buildings and causing potential damage. |
| Compressible Ground | Ground Stability | Some types of ground may contain layers of very soft materials like clay or peat. These may compress if loaded by overlying structures or if the groundwater level changes, potentially resulting in depression of the ground and disturbance of foundations. |
| Natural Ground Stability | Ground Stability | Natural ground stability considers ground stability issues from shrink swell, running sands, compressible ground, collapsible deposits, soluble rock and landslides. |
| Collapsible Deposits | Ground Stability | If the material below a building collapses, it may cause the building foundations to rapidly subside. If the ground collapses unevenly, the resulting damage may be more severe than that caused by a uniform collapse. |
| Artificial Ground Stability | Ground Stability | Artificial ground is the term we use for those areas where the ground surface has been significantly modified by human activity. |
| Artificial Ground | Ground Stability | Artificial ground is the term we use for those areas where the ground at or near the surface has been significantly modified by human activity. Typically, this includes ground that has been deposited (Made Ground) or excavated (Worked Ground), or some combination of Landscaped Ground or Disturbed Ground. BGS maps do not indicate the thickness or composition of deposits comprising Artificial Ground, it should be borne in mind that such deposits may well be highly variable in character (including a range of waste materials) and potentially exhibit a range of engineering characteristics due to their heterogenous nature (i.e. they may be compressible, unstable or require careful handling). |
| Landslides | Ground Stability | Landslides occur ultimately due to the effect of gravity, although other factors can all contribute to the overall stability of a slope. Landslides are commonly divided into four categories: falls, topples, slides or flows. |
| Dissolution of Soluble Rocks | Ground Stability | Ground dissolution occurs when certain types of rocks, containing layers of soluble material, get wet and the soluble material dissolves. This can cause underground cavities to develop. These cavities reduce support to the ground above and can lead to a collapse of overlying rocks. The Dissolution of Soluble Rocks dataset (procured from BGS GeoSure data product) uses a number of datasets in its creation. These include: • geology (bedrock, superficial, artificial, mass movement) • digital terrain model • superficial deposits thickness model • karstic/non-karstic geology • glacial limits • superficial permeability |
| Shrink Swell | Climate Change | This dataset provides insight on the likelihood that foundations will be affected by increased clay shrink-swell in the future, compared to current conditions, as a result of climate change. |
| Flooding | Climate Change | This dataset provides insight on the likelihood that the property will be affected by flooding from all sources (fluvial, pluvial, tidal and groundwater) in the future, compared to current conditions, as a result of climate change. |