Risk Assessment of Coastal Infrastructure

The aim of the research is to provide a probabilistic framework for assessing the risk to coastal infrastructure exposed to flooding and erosion. This will be achieved by considering the vulnerability of respective infrastructures to the physical hazards associated with coastal inundation. The risk assessment involves handling of quantitative and qualitative uncertainties, and the incorporation of quantitative analysis into a qualitative framework.
The hazards considered are astronomical tide, storm surge and wind waves. Tide and storm surge are initially being evaluated using a finite volume community ocean model (FVCOM) developed for the Firth of Clyde region. Surrogate models will be constructed to increase computational efficiency for further analysis. This can also provide a platform for real time forecasting. The uncertainties are treated quantitatively at this stage based on the probability distributions for the tide and surge outputs and the physical inputs.
Wind wave hazard will be assessed by coupling the outputs from the tide and surge model with the near shore wave simulation model (SWAN) for the same computational grid. A surrogate model will also be constructed using the outputs from this model to increase computational efficiency for further analysis. Similarly, this can provide a platform for real time forecasting. The uncertainties are treated quantitatively at this stage based on the probability distributions of the wind-wave outputs.
Vulnerability of individual structures will be assessed by deploying fragility curves for all relevant infrastructures. This includes the defence structures themselves as well as the social infrastructure that is adjacent to the coastline. These curves are in part derived from expert opinion, in which case the uncertainty is qualitative. Consideration is also given to the spread of coastal inundation, based on the topography of the local coastline. Data has also been collected from Argyll and Bute council regarding the location and condition of its coastal defence structures. The condition factor of the defence structure is also derived from expert opinion.
The system risk can then be computed by assessing all components, quantitative and qualitative, within the same framework.