Regional vulnerability analysis of Catalan beaches to storms

A framework to estimate coastal vulnerability to storm impacts at a regional scale is presented. It assesses the physical coastal vulnerability to storm impacts by separately estimating two components: flooding and erosion. It covers the following steps: characterisation of the forcing; evaluation of the induced beach response - inundation and erosion - (hazards quantification); coastal zone characterisation; definition of a coastal vulnerability index to storms - a composite of two partial vulnerability estimations, namely the flood vulnerability and the erosion vulnerability indices; and assessment of the coastal vulnerability. Instead of assessing the vulnerability associated with a given storm, the forcing is defined in terms of representative storms which are obtained by classifying storms in the area using a five-class system similar to that used for hurricanes (weak, moderate, significant, severe and extreme). Later, a vulnerability assessment for the entire coast to each storm category is produced. The method has been derived for and applied to the Catalan coast (north-west Mediterranean) but can be easily adapted to other coasts. It permits managers to identify coastal stretches sensitive to a given storm class for a given induced hazard (flooding, erosion or combination of both) to decide where to take actions.