The data comprises four GIS layers representing the permeability of geological deposits for Great Britain (bedrock, superficial, artificial and mass movement deposits). The permeability data has been derived from DiGMap-GB (Digital Geological Map Data of Great Britain), and therefore reflects the scale of DiGMap-GB. For the majority of the Great Britain, the scale is 1:50,000, however in areas where the geology is not mapped to this scale, the next best available scale is used. For bedrock deposits this is 1:250,000 and for superficial deposits this is 1:625:000. Artificial ground and mass movement deposits have not been mapped beyond 1:50,000. The data is updated annually, or after a major new release of DiGMap-GB. The permeability data describes the fresh water flow through geological deposits and the ability of a lithostratigraphical unit to transmit water. Maximum and minimum permeability indices are given for each geological unit to indicate the range in permeability likely to be encountered and the predominant flow mechanism (fracture or intergranular). Neither of the assigned values takes into account the thickness of either the unsaturated or saturated part of the lithostratigraphical unit. The data can be used freely internally, but is licensed for commercial use. It is best displayed using a desktop GIS, and is available in vector format as ESRI shapefiles and MapInfo TAB files.
The GeoSure data sets and reports from the British Geological Survey provide information about potential ground movement or subsidence in a helpful and user-friendly format. The reports can help inform planning decisions and indicate causes of subsidence. The methodology is based on BGS DiGMap (Digital Map) and expert knowledge of the behaviour of the formations so defined. This dataset provides an assessment of the potential for a geological deposit to show running sand behaviour under the action of flowing water, a characteristic usually of saturated sand and silt grade material. Complete Great Britain national coverage is available. The storage formats of the data are ESRI and MapInfo but other formats can be supplied.
The data comprises GIS layers representing the permeability of mass movement deposits for Great Britain. The permeability data has been derived from DiGMap-GB (Digital Geological Map Data of Great Britain), and therefore reflects the scale of DiGMap-GB. For the majority of the Great Britain, the scale is 1:50,000,. The data is updated annually, or after a major new release of DiGMap-GB. The permeability data describes the fresh water flow through mass movement deposits and the ability of a unit to transmit water. Maximum and minimum permeability indices are given for each geological unit to indicate the range in permeability likely to be encountered and the predominant flow mechanism (fracture or intergranular). Neither of the assigned values takes into account the thickness of either the unsaturated or saturated part of the lithostratigraphical unit. The data can be used freely internally, but is licensed for commercial use. It is best displayed using a desktop GIS, and is available in vector format as ESRI shapefiles and MapInfo TAB files.
This dataset has now been superseded, please see the Estimated Ambient Background Soil Chemistry Scotland dataset. The BGS digital soil chemistry data indicates the estimated geometric mean concentrations (mg kg-1) of Arsenic (As), Cadmium (Cd), Chromium (Cr), Nickel (Ni) and Lead (Pb) in surface soil. The soil chemistry data is based on GBASE (Geochemical Baseline Survey of the Environment) soil geochemical data where these are available. Elsewhere the stream sediment data are converted to surface soil equivalent potentially harmful element(PHE) concentrations. This dataset covers Scotland but data is available for the whole of Great Britain, with the exception of the London area where an inadequate number of geochemical samples are available at the moment.
Data identifying landscape areas (shown as polygons) attributed with geological names. The scale of the data is 1:50 000 scale. Onshore coverage is provided for all of England, Wales, Scotland and the Isle of Man. Data are supplied as five themes: bedrock, superficial deposits, mass movement, artificial ground and linear features. Bedrock geology describes the main mass of solid rocks forming the earth's crust. Bedrock is present everywhere, whether exposed at surface in outcrops or concealed beneath superficial deposits or water bodies. Geological names are based on the lithostratigraphic or lithodemic hierarchy. The lithostratigraphic scheme arranges rock bodies into units based on rock-type and geological time of formation. Where rock-types do not fit into the lithostratigraphic scheme, for example intrusive, deformed rocks subjected to heat and pressure resulting in new or changed rock types; then their classification is based on their rock-type or lithological composition. This assesses visible features such as texture, structure, mineralogy. Superficial deposits are younger geological deposits formed during the most recent geological time; the Quaternary. These deposits rest on older rocks or deposits referred to as bedrock. The superficial deposits theme defines landscape areas (shown as polygons) attributed with a geological name and their deposit-type or lithological composition. Mass movement describes areas where deposits have moved down slope under gravity to form landslips. These landslips can affect bedrock, superficial or artificial ground. Mass movement deposits are described in the BGS Rock Classification Scheme Volume 4. However this data also includes foundered strata, where ground has collapsed due to subsidence (this is not described in the Rock Classification Scheme). Caution should be exercised with this data; historically BGS has not always recorded mass movement events and due to the dynamic nature of occurrence significant changes may have occurred since the data was released. Artificial (man-made) theme (shown as polygons) indicates areas where the ground surface has been significantly modified by human activity. Whilst artificial ground may not be considered as part of the 'real geology' of bedrock and superficial deposits it does affect them. Artificial ground impacts on the near surface ground conditions which are important to human activities and economic development. Due to the constantly changing nature of land use and re-use/redevelopment, caution must be exercised when using this data as it represents a snapshot in time rather than an evolving picture hence the data may become dated very rapidly. Linear features (shown as polylines) represent geological structural features e.g. faults, folds or landforms e.g. buried channels, glacial drainage channels at the ground or bedrock surface (beneath superficial deposits). Linear features are associated most closely with the bedrock theme either as an intrinsic part of it for example marine bands or affecting it in the case of faults. Landform elements are associated with both bedrock and superficial deposits. All five data themes are available in vector format (containing the geometry of each feature linked to a database record describing their attributes) as ESRI shapefiles and are available under BGS data licence.
The GeoSure data sets and reports from the British Geological Survey provide information about potential ground movement or subsidence in a helpful and user-friendly format. The reports can help inform planning decisions and indicate causes of subsidence. The methodology is based on BGS DiGMap (Digital Map) and expert knowledge of the behaviour of the formations so defined. This dataset provides an assessment of the potential for a geological deposit to compress under an applied load, a characteristic usually of superficial deposits such as peat or alluvium. 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. Complete Great Britain national coverage is available. The storage formats of the data are ESRI and MapInfo but other formats can be supplied.
This dataset is the Derived Postcode Database issued as part of the GeoSure Insurance V7 incorporating postcode data from OS Code-Point Open version 2016.1. The GeoSure Insurance Product (including the Derived Postcode Database) represents the end of an interpretation process, starting with the BGS Digital Geological Map of Great Britain at the 1:50,000 scale (DiGMapGB-50). This digital map is the definitive record of the types of rocks underlying Great Britain (excluding the Isle of Man), as represented by various layers, starting with Bedrock and moving up to overlying Superficial layers. In 2003, the BGS also published a series of GIS digital maps identifying areas of potential natural ground movement hazard in Great Britain, called GeoSure. There are six separate hazards considered - shrink-swell clays, slope instability, dissolution of soluble ground, running sand, compressible and collapsible deposits. These maps were derived by combining the rock-type information from DiGMapGB-50 with a series of other influencing factors which may cause the geological hazards (e.g. steep slopes, groundwater). In 2005, the BGS used the GeoSure maps to make an interpretation of subsidence insurance risk for Great Britain property insurance industry, released as the new GeoSure Insurance Product. This represents the combined effects of the 6 GeoSure hazards on (low-rise) buildings in a postcode database - the Derived Postcode Database, which can be accompanied by GIS maps showing the most significant hazard areas. The combined hazard is represented numerically in the Derived Postcode Database as the Total Hazard Score, with a breakdown into the component hazards. The GeoSure Derived Postcode Database (DPD) is a stand-alone database, which can be provided separately to the full GeoSure Insurance Product V7. The methodology behind the DPD involves balancing the 6 GeoSure natural ground stability hazards against each other. The GeoSure maps themselves have a fivefold coding (A to E), and the balancing exercise involves comparing each level across the six hazards e.g. comparing a level C shrink-swell clay area with a level C running sand area. The comparison is done by a process involving expert analysis and statistical interpretations to estimate the potential damage to a property (specifically low-rise buildings only). Each level of each of the hazards is given a 'hazard score' which can then be added together to derive a Total Hazard Score at a particular location (e.g. within a given postcode).
The BGS digital estimated urban soil chemistry data (GB_EstimatedUrbanSoilChemistry_v3) indicates the estimated geometric mean concentrations (mg kg-1) of Arsenic (As), Cadmium (Cd), Chromium (Cr), Nickel (Ni) and Lead (Pb) in topsoil derived by spatial interpolation of the point source urban soil chemistry data. The information is relevant for the first stage of any assessment of risks to human health required by regulatory authorities in relation to land use and also assessing ecological risks. Estimated topsoil PHE (Potentially Harmful Element) concentrations above respective SGVs (Soil Guideline Value) do not necessarily imply a significant health risk but they do highlight the need to consider whether or not there may be a risk. Comparison of this spatially referenced geochemical data set with information on current or historic land use and geological information might help environmental professionals decide whether high PHE concentrations in topsoils can be attributed to geogenic or anthropogenic sources. The dataset is based on, and limited to, an interpretation of the records in the possession of the BGS at the time the dataset was created. An indication of high estimated PHE concentrations in soil does not necessarily mean that an individual site will have a high PHE concentration. Topsoil concentrations in urban areas are frequently characterised by strong spatial variation over short distances so this data should be interpreted and used with caution. The original urban topsoil samples were collected and analysed as part of the BGS Geochemical Baseline Survey of the Environment (G-BASE) project.
The 1km Hex Mining Hazard (Not Including Coal) v7 dataset shows areas of known underground mining (Not Including Coal), identified with an indication of the level of hazard associated for each site. The presence of former underground workings, particularly where shallow, may collapse and cause surface settlement which is used to identify potential hazard at each site. The rating is based on a Low (limited mining known to have occurred) to High (underground mining is known to have occurred) scale. The dataset covers areas of known underground working in Great Britain. The coverage is not comprehensive as areas with no evidence of underground working are unclassified. Underground extraction of minerals and rocks has taken place in Great Britain for more than 5000 years. This dataset draws together a range of diverse information; the geology, the primary constraint on distribution; additional information sourced from published literature and knowledge from BGS experts. Derived from the original MiningHazardNotIncludingCoalGB_v7 dataset, this layer generalises these data into a Hex grid format, with an effective hexagonal grid resolution of 2.6km coverage area (side length of 1km). The dataset was created to provide a comprehensive overview of Great Britain's long and complicated mining legacy. It provides essential information for planners and developers working in areas where former underground mine workings may have occurred. Also for anyone involved in the ownership or management of property, including developers, householders and local government.
The G-BASE programme involves systematic sampling and the determination of chemical elements in samples of stream sediment, stream water and soil, to build up a picture of the surface chemistry of the UK. The average sample density for stream sediments and water is about one site per 1.5-2km square, and for soils one site per 2km square. Analytical precision is high with strict quality control to ensure countrywide consistency. Results have been standardised to ensure seamless joins between geochemical sampling campaigns. The data provide baseline information on the natural abundances of elements, against which anomalous values due to such factors as mineralisation and industrial contamination may be compared. Analytical data for the 150 microns fraction of soil and stream sediment samples are available for some or all of: Ag, As, B, Ba, Bi, Be, Ca, Ce, Cd, Co, Cr, Cs, Cu, Fe, Ga, K, La, Li, Mg, Mn, Mo, Nb, Ni, P, Pb, Rb, Sb, Se, Sn, Sr, Th, Ti, U, V, Y, Zn, and Zr. Most water samples have been analysed for alkalinity, pH, conductivity, F and U and some for multi-element analyses including Al, Cl, Na, Si, SO4,NO4, and TOC. The project now routinely determines the elements listed in the <2mm fraction of surface soils.