Landslide management in the UK—the problem of managing hazards in a ‘low-risk’ environment

Abstract

As a country with limited direct experience of natural disasters, the UK has not developed a sophisticated legal and regulatory framework for the mitigation for many of the geological hazards, including landslides, which affect the population. Although the 1966 Aberfan disaster led to a limited amount of research into landslide distribution and mechanisms, it left no long-term legacy of managing landslide risks. A number of high-profile events in the late 20 th Century, and a series of 'near-misses' since then have failed to stimulate a significant social or economic awareness. Perhaps understandably, this has limited political motivation to develop landslide management policies. This paper examines this situation and discusses some implications of how landslides are dealt with by the UK government and devolved governments in Scotland, Wales and Northern Ireland.Policy is based mainly upon national assessments of geohazards (including landslides) carried out in the 1980s and 1990s. These assessments provided the basis for planning policies and guidance that to some degree control development on or around unstable ground. Although this was an encouraging start, limited resources and political support over the longer term ultimately meant these initiatives failed to develop into an effective, integrated, national response to landslide hazards. Policies and regulations are open to interpretations which vary between devolved governments, building regulations and local planning offices.Crucially, the resulting system offers no framework for the legal or financial responsibilities for hazard management. As a result, landslide management in the UK has been influenced more by planning and political structure than actual risks to the population. This situation partially arises from the limited data available on the overall cost of landslides on a national basis. Until this situation is rectified it will be difficult to establish a mitigation strategy based on risk.This paper discusses how landslides are managed in the UK and provides examples from around the country of how the system responded to some serious landslides occurring over the last twenty years. Examples are presented that show how this framework has affected the investigation and mitigation of different types of landslides. The paper also briefly discusses the role of insurance in landslide hazard management and highlights the effective response of Transport Scotland in the aftermath of the debris flows in 2004.

The National Landslide Database of Great Britain: Acquisition, communication and the role of social media

“…Coupled with improved media search engines and the incorporation of slope failures, the use of social media as a data gathering tool has facilitated the increase from 10-15 (Gibson et al, 2013) to 150-200 new landslide events per year. As a result, care must be taken in the interpretation of Figure 1 as the number of landslides detected by media search engines and social media before August 2012 is fewer.…”

“…In terms of landsliding, Great Britain is a low risk environment (Gibson et al, 2013) with small scale failures and low fatality rates. Past events which represent significant impacts of landslides in Great Britain have been dominated by incidents that were large scale (e.g.…”

Natural and Anthropogenic Geohazards in Greater London Observed from Geological and ERS-1/2 and ENVISAT Persistent Scatterers Ground Motion Data: Results from the EC FP7-SPACE PanGeo Project

“…GIBSON et al (2013) analyse aspects related to management of landslide hazards in an environment considered as low-risk, but where the financial loss from such a hazard is likely to be in excess of £10 million per year. FARRANT and COOPER (2008) investigate geological properties of soluble rocks, and report on karstic features observed in Carboniferous limestone, chalk and Permo-Triassic gypsum and halite.…”

“…Developed at a scale of 1:50,000, this data set provides information about potential natural ground movement resulting from collapsible deposits, compressible ground, landslides (GIBSON et al 2013), running sand, shrinkswell (HARRISON et al 2012) and soluble rocks (COOPER et al 2011). Susceptibility is classified using an A (lowest) to E (highest) rating for each of these six geohazard types (BGS 2014).…”

Stability monitoring of a rail slope using acoustic emission

“…Reactivated landslides in the UK that move seasonally each year (i.e. in response to intense and/or prolonged periods of rainfall, and therefore transient elevations in pore-water pressure) cause annual expenses over consecutive years of the order of millions of pounds, due to structural damage, insurance costs, engineering measures and remediation (these cost estimates relate mostly to direct effects; little information is available on indirect costs associated with disruption to traffic and the local economy) (Gibson et al, 2013). There is growing concern that climate change will result in increased frequency and severity of reactivated and first-time slope failures in the coming decades (Dijkstra and Dixon, 2010).…”