newGeoSure Insurance Product version 7 2015.1

**This dataset has been superseded** The newGeoSure Insurance Product (newGIP) provides the potential insurance risk due to natural ground movement. It incorporates the combined effects of the 6 GeoSure hazards on (low-rise) buildings. This data is available as vector data, 25m gridded data or alternatively linked to a postcode database – the Derived Postcode Database. A series of GIS (Geographical Information System) maps show the most significant hazard areas. The ground movement, or subsidence, hazards included are landslides, shrink-swell clays, soluble rocks, running sands, compressible ground and collapsible deposits. The newGeoSure Insurance Product uses the individual GeoSure data layers and evaluates them using a series of processes including statistical analyses and expert elicitation techniques to create a derived product that can be used for insurance purposes such as identifying and estimating risk and susceptibility. The Derived Postcode Database (DPD) contains generalised information at a postcode level. The DPD is designed to provide a ‘summary’ value representing the combined effects of the GeoSure dataset across a postcode sector area. It is available as a GIS point dataset or a text (.txt) file format. The DPD contains a normalised hazard rating for each of the 6 GeoSure themes hazards (i.e. each GeoSure theme has been balanced against each other) and a combined unified hazard rating for each postcode in Great Britain. The combined hazard rating for each postcode is available as a standalone product. The Derived Postcode Database is available in a point data format or text file format. It is available in a range of GIS formats including ArcGIS (*.shp), ArcInfo Coverages and MapInfo (*.tab). More specialised formats may be available but may incur additional processing costs. The newGeoSure Insurance Product dataset has been created as vector data but is also available as a raster grid. This data is available in a range of GIS formats, including ArcGIS (*.shp), ArcInfo coverage’s and MapInfo (*.tab). More specialised formats may be available but may incur additional processing costs. Data for the newGIP is provided for national coverage across Great Britain. The newGeoSure Insurance Product dataset is produced for use at 1:50 000 scale providing 50 m ground resolution. This dataset has been specifically developed for the insurance of low-rise buildings. The GeoSure datasets have been developed to identify the potential hazard for low-rise buildings and those with shallow foundations of less than 2 m deep. The identification of ground instability and other geological hazards can assist regional planners; rapidly identifying areas with potential problems and aid local government offices in making development plans by helping to define land suited to different uses. Other users of these data may include developers, homeowners, solicitors, loss adjusters, the insurance industry, architects and surveyors. Version 7 released June 2015.

Alternate title: newGIP v7 2015

Date (Creation): 2015-05-22

Identifier: http://data.bgs.ac.uk/id/dataHolding/13606634

Distributor

British Geological Survey - Enquiries

Environmental Science Centre, Nicker Hill, Keyworth , NOTTINGHAM , NOTTINGHAMSHIRE , NG12 5GG , United Kingdom

0115 936 3143
0115 936 3276

Point of contact

British Geological Survey - Enquiries

Environmental Science Centre, Nicker Hill, Keyworth , NOTTINGHAM , NOTTINGHAMSHIRE , NG12 5GG , United Kingdom

0115 936 3143
0115 936 3276

Maintenance and update frequency: biannually Biannually

GEMET - INSPIRE themes, version 1.0

Geology

BGS Thesaurus of Geosciences

UK Location (INSPIRE)
Natural hazards

dataCentre

UK Location (INSPIRE)

Keywords

NERC_DDC

Access constraints: otherRestrictions Other restrictions

Other constraints: This information has commercial potential and access should be subject to the Programme Manager's approval (Kathryn Lee). The information should not be used to indicate actual hazard at a site. It does not assess if the hazard is actually present. This can only be determined by a site specific assessment.

Use constraints: otherRestrictions Other restrictions

Other constraints: The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused.

Other constraints: The dataset is made available to external clients under BGS Digital Data Licence terms and conditions. Revert to the IPR Section (iprdigital@bgs.ac.uk ) if further advice is required with regard to permitted usage.

Spatial representation type: vector Vector

Denominator: 50000

Metadata language: EnglishEnglish

Topic category

Geoscientific information

Geographic identifier

ENG

Date (Revision): 2009

Geographic identifier

ENGLAND [id=150000]

Date (Creation): 1979

Geographic identifier

SCOTLAND [id=140000]

Date (Creation): 1979

Geographic identifier

SCT

Date (Revision): 2009

Geographic identifier

WALES [id=170000]

Date (Creation): 1979

Geographic identifier

WLS

Date (Revision): 2009

End date: 2015 Before

Supplemental Information: 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 estimating how frequently a ground movement event may occur that could have the potential to damage a property (in particular, low-rise buildings). Each level of each of the hazards is given an 'occurrence factor' (as shown in Table 1 of the user guide), which can then be added together to derive a Total Occurrence Factor at a particular location (e.g. within a given postcode). In 2003, the BGS also published a series of GIS digital maps identifying areas of potential natural ground movement hazard in the UK, called GeoSure. There are six separate hazards considered - shrink-swell clays, slope instability, dissolution of soluble ground, running sand, compressible ground and collapsible ground. These maps were derived by combining the rock classification scheme (RCS) information from DiGMapGB-50 with a series of other factors which may cause the geological hazards (e.g. steep slopes, groundwater). In 2007, the BGS used the GeoSure maps to make an interpretation of subsidence insurance risk for the UK 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 Occurrence Factor, with a breakdown into the component hazards, as described in more detail below. GeoSure Derived Postcode Database (DPD) The DPD is a stand-alone database, which can be provided separately to the visualisation layers in the Full GeoSure Insurance Product.

Unique resource identifier: OSGB 1936 / British National Grid (EPSG::27700)

Distribution format

Postcode Database ( Current BGS version )
ESRI Shapefile ( Current BGS version )
Map Info File ( Current BGS version )

Distributor

British Geological Survey - Enquiries

Environmental Science Centre, Nicker Hill, Keyworth , NOTTINGHAM , NOTTINGHAMSHIRE , NG12 5GG , United Kingdom

0115 936 3143
0115 936 3276

OnLine resource: http://www.bgs.ac.uk/products/geohazards/geosureInsurance.html

Hierarchy level: dataset Dataset

Other: dataset

Conformance result

Date (Publication): 2011

Explanation: See the referenced specification

Pass: No

Conformance result

Date (Publication): 2010-12-08

Explanation: See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:323:0011:0102:EN:PDF

Pass: No

Statement: In detail, the methodology behind producing the DPD is as follows: 1. The postcode centroids layer, as supplied by Ordnance Survey, is buffered using a value of 300 metres. This value takes into account the variability in size of postcodes (250 metres) and the 50 metres cartographic precision of the Digital Geological Map of Great Britain at the 1:50,000 scale (DiGMapGB-50) data that is used as the geological basis for the GeoSure hazard layers. 2. An 'occurrence rating' is then assigned to each of the A-E levels of each master GeoSure hazard layer. These occurrence ratings represent how frequently a ground movement event may occur that could have the potential to damage a property (in particular, low-rise buildings). The occurrence ratings are then multiplied by a nominal score (100) in order to derive a series of 'unified ratings'. Before use in the DPD, these unified rating values in the table are then multiplied by 10 allow the use of integer values. For example a class 'D' shrink-swell pixel will have a value of 10 x 10 = 100. 3. Zonal statistics are then calculated using the buffered postcode layer from above in conjunction with each of the six GeoSure hazard grids (25m pixel size). This process considers each hazard in turn and calculates the average of the pixel values that occur within each of the buffered postcodes (circular areas). As each pixel covers the same area the resultant average represents the area-weighted average of the hazard values within the circular area. These average values for each hazard are added to the output Derived Postcode Database as 'occurrence factors'. 4. The six hazard occurrence factors for each postcode are summed and added to the DPD as column Total_of (Postcode Total Occurrence Factor, PTOF). 5. The Total_of column is classified into 5 classes divided into 5 equal categories as shown in table 3 of the newGeoSure Insurance Product: Methodology report. (IR/12/074). This classification is added as column Class5 with values of 1-10. This, and the Class5 split, is done in order to allow easier interpretation and visualisation of the total hazard if required (for example, Class5 can be used to colour up the postcode centroid in the GIS to show how the total hazard varies across an area).