Is your region susceptible? Britain’s geohazard hotspots revealed

Scientists at the British Geological Survey (BGS) have published UK regional hazard maps revealing the most susceptible local authority regions around the country. The maps provide regional decision makers with an overview of the relevant hazards in their local area and provide an important indication of where more detailed hazard data may be required.

The analysis considers the occurrence of eight key geohazards relating to natural subsidence, the presence of the ground-gas radon, and the possibility of legacy mining in an area (excluding coal).

Regions in the south (Devon; Dorset; Hampshire; Kent; Surrey; Wiltshire; West Sussex) and north (Cumbria; North Yorkshire; Northumberland) of England are shown to be the most susceptible, with some regions affected by all eight hazards. The Outer Hebrides and Halton (south of Liverpool) were revealed to be the least susceptible, with exposure to three or fewer hazards.

Various geological properties and processes are associated with each hazard but the majority result in some form of ground movement, causing similar societal impacts and damage to infrastructure and homes. For example, collapsible deposits, compressible ground, running sands and shrink-swell subsidence can all result in damage to roads and pathways, breaks in utility pipes and damage to foundations and buildings. Former underground workings and soluble rocks can both cause larger underground cavities that may be prone to collapse, causing more significant and sudden movement and damage. Radon is the exception; it is a natural radioactive gas that can enter buildings from the ground and can increase the risk to human health where there is exposure to high concentrations.

Figures released by the Association of British Insurers show thousands of claims relating to ground movement such as subsidence are being made annually, costing millions of pounds to remediate. Network Rail has revealed landslide damage to the rail network costs tens of millions pounds a year to repair and there are dramatic examples of legacy mine and soluble rock collapses causing sudden and catastrophic damage to residential areas. Radon gas is linked to over 1100 deaths from lung cancer in the UK each year.

It is important to note that there are other active hazards such as river and coastal erosion affecting some local authority regions, not yet included in this study. 

To create these maps, BGS has simplified and summarised its geological information. In this generalised form they give an indication as to which geohazards are most prevalent per region. For a more detailed view of specific areas that are most prone to particular geohazards risks please visit the BGS data product webpages for mining hazards (non including coal), ground instability and radon gas to find out how to access higher-resolution data.

BGS has compiled its most comprehensive and authoritative datasets in this way to provide the maximum support for a diverse range of stakeholders, ranging from regulators to policymakers and planners.

Presenting the data in this generalised manner provides a quick and convenient indication as to which geohazards are most prevalent by region, informing mitigation strategies and the acquisition of higher resolution data. We would encourage anyone interested in our hazard data to contact us or visit our dataset webpages for more information.

Katy Lee – BGS Product Portfolio Manager

The underlying BGS geohazard datasets from which these statistics are derived are each presented as five susceptibility classes per hazard. The summary maps shown here present statistics relating the upper three classifications which represent areas most likely to be impacted by the respective hazards. For the BGS GeoSure and mining hazard (not including coal) ground instability hazards these upper three classes represent areas where susceptibility to ground instability is possible, probable or known.  The BGS Radon Potential upper three classes cover 95 per cent of homes estimated to be at or above the threshold guideline for radon levels (200 becquerels per cubic metre).

For full details of the classification breakdown, please refer to the respective dataset product user guides:

• BGS GeoSure
• BGS Indicative Atlas of Radon
• Mining hazard (not including coal)

Download the maps

• Geohazard susceptibility in each British local authority
• Most prevalent geohazards per local authority

Further information on the assessed hazards:

If you have any queries about the BGS data available to support hazard susceptibility assessments please get in touch (digitaldata@bgs.ac.uk) or visit our dataset webpages for more information.