Download Figure 1: Isle of Wight Study Frontage

Development of an Integrated Model to Determine the
Impacts of Climate Change on Coastal Recession
1) Problem Statement
Soft rock cliffs create geomorphologically diverse
coastlines owing to the complex interactions
between geology, combined with the applied forces
of marine and terrestrial processes. They are highly
susceptible to recession and one key challenge is to
understand how climate change aspects (e.g. sealevel rise, increased seasonal rainfall) will alter this
process. As such, traditional methods to predict
recession (by extrapolation of historic rates) should
no longer be considered acceptable when past
conditions are not representative of the future. In
response one alternative method is process-based
numerical modelling, which enables system changes
and process interactions to be simulated. However,
this method is relatively in its infancy and many
models are criticised for the generalised manner in
which they treat cliff behaviour. This relates to the
key assumption that it is coastal processes that drive
recession. This may be problematic for complex cliff
sites, potentially leading to inaccurate future
predictions of cliff-top position if the effect of
climatic factors on slope stability are omitted.
2) Research Description
The aim of this study is to develop a coupled,
process-based model which considers the influence
of both coastal and slope (geotechnical) processes
on soft cliff recession. The model will be developed
considering the complex study frontage of the southwest coast of the Isle of Wight, UK (Figure 1).
Figure 1: Isle of Wight Study Frontage
This 17km site has a varied soft rock geology,
exhibiting a series of headlands and a range of cliff
behavioural units. Therefore, it provides strong
opportunities to validate the more integrated coastal
cliff recession model than those currently available.
3) Preliminary Results
Considering the complexity of the cliff recession process, the first stage has been to develop a generalised
conceptual model (Figure 2) to understand all systems, parameters and processes involved in the cliff
recession process. This highlights the plethora of interactions and feedback mechanisms within the cliff
system and subsequently will form the foundation for the development of the numerical model.
Figure 2: Generalised Conceptual Model of Soft Cliff Coastal Recession
www.southampton.ac.uk
Contact: Natasha Carpenter (PhD student)
Civil Engineering and the Environment
[email protected],