Analysis of potential impacts on coastal areas due to changes in wave conditions

Abstract

This study examines the main physical processes related to coastal and port engineering that could be altered by future changes in wave parameters as a consequence of climate change. To estimate the order of magnitude of the potential changes in these processes, several assumptions and simplifications are made and, in most cases, they are assessed by using simple, empirical state-of-the-art expressions. The studied processes are grouped in three categories according to whether they affect beaches, harbors or coastal structures in general. The changes in these processes are estimated as a function of the deepwater variations of the main wave parameters: wave height (H 0), wave period (T) and wave direction (θ 0). A moderate range of variation is assumed for these parameters at deep water (±10 or ±20 % in H 0 and its square root in T, and ±10o in θ 0), taking into account recent studies of future wave projections. The results indicate that potential changes in wave height will strongly affect overtopping discharge, stability and scouring of rubble-mound structures and, to a lesser extent, siltation, wave transmission and longshore sediment transport. Changes in wave direction will affect longshore sediment transport in particular and, at a lower magnitude, processes related to port operability (agitation and siltation). Siltation is the only process affected significantly by changes in T alone.