Over 15,000 landslides (inland and coastal) have been recorded within the United Kingdom (UK), with some of the largest and well known landslide complexes (i.e. Ventnor Undercliff, Isle of Wight) being in a coastal setting. The demand for growth of residential, commercial and infrastructure development near coastal areas has increased in recent years necessitating a need for development on areas presenting a first time or recurring slope failure. With a current average cost of £126 million per year, it can be seen that coastal erosion of which landslides encompass the majority of this term, are a major cause of economic concern.
Although wave action is the obvious mechanism for coastal erosion and subsequent onset for landslide activity there are many soil and climatic factors (e.g. soil type, land use cover, permeability, clay mineralogy, pore water pressure, rainfall etc.) that are considered the main triggering factors with wave action occasionally being a subsidiary factor.
With an average of approximately 28 landslides per year having been recorded by the UK media since 2005 and the year 2012 showing an increased number of ‘shallow’ landslides assumed to be as a result of intense rainfall, there is a need to correlate periods of future intense/prolonged rainfall in light of a predicted future climate in order to assess the future frequency of landslide activity in coastal areas.
This brief summary report aims to introduce the impact and prevalence of landslides in a UK coastal context and understand the soil processes as triggering mechanisms to slope instability, and to differentiate these triggering mechanisms from the direct wave erosional action of the sea. This summary then hopes to suggest how the ground (soil) conditions (triggering mechanisms) and climate change interact, the understanding of such could give reliable estimates of landslide hazards and frequency in a coastal UK setting.