Sep 21 2005
New BGS GeoSure datasets
Landmark will be replacing the British Geological Society (BGS) GeoHazard data with the new BGS GeoSure data. The new GeoSure datasets assess the potential for a hazard to occur in an area, providing you with information about potential ground movement or subsidence which can help inform planning decisions and indicate causes of subsidence. Unlike the old data, this new data will be site specific, giving you a more accurate and reliable assessment of your site.
In addition 'Hazard Potential' will replace 'Risk' as the reporting attribute
The new BGS GeoSure datasets will give you valuable information about:
Soluble rocks (dissolution)
Parts of Britain are underlain by soluble rocks that can dissolve causing subsidence. These rocks vary from moderately soluble limestone and chalk to highly soluble gypsum and salt. All these rocks can dissolve and create surface depressions, an uneven buried rock surface or underground caves and cavities.
Shrink swell
Clay that absorbs water may be a significant hazard to buildings and structures due to its ability to shrink or swell with seasonal changes in water content. Local changes such as leaks from water pipes or drains, or following the removal, planting or severe pruning of trees can also cause these clays to swell or shrink.
Landslides (slope instability)
A landslide is the outward and downward movement of rock or soil on a slope. Many landslides are mapped and their presence known, however there are many other locations that are also at risk for which no slope movement has been recorded. A small change in drainage or an increased loading due to the weight of a new structure could trigger a landslide in a previously stable area.
Compressible ground
Weak ground compresses when a load, such as a house is placed on it. Typically the house will sink into the ground. If the ground compresses unevenly the house will crack and suffer greater damage.
Running sand
Running sand is the flow of sand into an excavation or void due to water pressure. Problems commonly occur when excavations meet the water table causing water to flush sand into the excavation. Potentially more hazardous is the break through of deep excavations or tunnels into water-saturated sands causing the water and sand to flow rapidly into the excavation.
Collapsible rocks
These rocks usually consist of with a low density and an open structure that means they can become unstable, when a critical load is exceeded or the material is saturated under load, resulting in a sudden collapse. Their fine-grained nature may make the rocks susceptible to heave as a result of frost action in some conditions.
Envirocheck and Sitecheck products will have On Site and 1-250m buffers; other reports will have a 0-50m buffer.
New and modified datasets
Local Authority Integrated Pollution Prevention and Control (LA IPPC's) dataset
This new dataset acts as an intermediate data set between IPPC's and LA-PPC's, now incorporating information regulated by both the Environment Agency and Local Authorities and covering a three tier system of Part A1, A2 and B consents. This dataset will be added to all environmental reports and feature in the Agency & Hydrological section of the Envirocheck Datasheet and the Summary ' Current Land Use ' Sources section under 'Industrial processes' in the Sitecheck products.
New attributes to the IPPC dataset
Three new attributes will be added to the IPPC dataset: 'Application Type', 'Application Sub Type' and 'Primary Activity Indicator'. Within the data, each IPPC license has a list of activities which occur at the site in question. The 'Primary Activity Indicator' is a Yes/No field which will indicate which activity is the primary activity at the site. These changes will be observed within the Envirocheck and Sitecheck Review product range.
Renaming of key datasets
- Change of name for National Radiological Protection Board (NRPB) to 'Health Protection Agency' (HPA)
- Renaming of the existing Air Pollution Controls (APC) dataset to Local Air Pollution Prevention and Controls (LAPPC)
- Renaming of Internet Street Mapping to Streetview giving you more up-to-date mapping