Media, Sinkholes and the UK National Karst Database

The British Geological Survey (BGS) maintains a number of databases that feed into hazard susceptibility assessments, including karst, landslide and mining susceptibility. The winter period from December 2013 to January 2014 was one of, if not the most, exceptional periods of winter rainfall in the last 248 years for England and Wales. During this period the Jet Stream diverted easterly tracking cyclones along a more southerly route than is usual across the United Kingdom (UK). This resulted in south-east and central-southern England experiencing total rainfall values of 372.2 mm for this period, which was the wettest two-month period since 1910. This period was associated with extensive flooding and increased numbers of slope failures, landslides and sinkholes, which affected transport routes into and out of London, thereby generating considerable media attention. In addition to government and stakeholder requirements, the BGS experienced an unusually high level of enquiries from the public and the media pertaining to sinkholes, which put an additional strain on resources, but is an acknowledged component of the BGS remit. During February alone, the BGS received reports of 19 sinkholes. The majority of these occurred in the Cretaceous chalk of southern England. Approximately half were not naturally occurring sinkholes, but were due to the collapse of anthropogenic features. Typically, the anthropogenic subsidence collapse features included: the collapse of chalk shafts associated with historic extraction of chalk for brickworks; the collapse of deneholes (medieval chalk workings for chalk for ground improvement), and chalk mine shaft collapses. This paper describes the National Karst Database, stakeholder requirements and how the BGS has responded with new and improved mechanisms for data collection, storage and dissemination