Modelo proceso-respuesta de recesión de acantilados por variación del nivel del mar. Aplicación en la Costa de Holderness (Reino Unido)

At the moment the development of predictive cliff-erosion models is limited from a geomorphological perspective due to the complex interactions existing between coupled processes acting over wide scales of time and space. Current models incorporate a probabilistic framework in order to simulate coastal recession events or cliff failure and tend to assess the effects of climate change through changes in the mean sea lea level. According to this procedure, the resulting simulations of cliffs with different behaviours might produce identical annual retreat characteristics even if their potential response to changing environments may not be the same. Thus, a new process-response model is developed to incorporate the behavioural characteristics of cohesive clay coasts with a protective talus wedge under erosive processes. To this end, the model incorporates dynamic marine processes such as variations in mean sea level, tides and waves together with cliff evolution in the shape of erosion, cliff failure and the formation of foot talus deposits. Cliff erosion is calculated on the basis of sea-level changes, wave incidence, shore platform slope and the uniaxial compressive strength of the rock over each tidal cycle. After each cycle the geomechanical stability against topple movement of the cliff face is evaluated and in the event of failure, a talus wedge is formed. The model has been corroborated by an assessment of profile evolution at various locations along a rapidly retreating area on the coast of Holderness in the UK. The results represent an important step-forward in linking material properties to cliff recession processes and the subsequent long-term coastal response in the face of changing sea-level conditions.