Modelling the Impact of Climate Change on Coastal Flooding: Implications for Coastal Structures Design

Achilleas Samaras,Theophanis Karambas

doi:10.3390/jmse9091008

Abstract

In the present work, the impact of climate change on coastal flooding is investigated through a set of interoperable models developed by the authors, following a modular modelling approach and adapting the modelling sequence to two separate objectives with respect to inundation over large-scale areas and coastal protection structures’ design. The modelling toolbox used includes a large-scale wave propagation model, a storm-induced circulation model, and an advanced nearshore wave propagation model based on the higher order Boussinesq-type equations, all of which are presented in detail. Model capabilities are validated and applications are made for projected scenarios of climate change-induced wave and storm surge events, simulating coastal flooding over the low-lying areas of a semi-enclosed bay and testing the effects of different structures on a typical sandy beach (both in northern Greece). This work is among the few in relevant literature that incorporate a fully non-linear wave model to a modelling system aimed at representing coastal flooding. Results highlight the capabilities of the presented modelling approach and set the basis for a comprehensive evaluation of the use of advanced modelling tools for the design of coastal protection and adaptation measures against future climatic pressures.

Highlights

Climate change is expected to have significant effects on the intensity and frequency of occurrence of extreme weather events, affecting sea levels, circulation patterns, currents and waves in oceans and seas around the world [1,2,3,4]
This interplay between waves and water levels dictates the characteristics of the models needed for the accurate representation of related processes, while scale issues allow the use of modular modelling approaches based on varying-complexity nesting schemes and the coupling of interoperable models
The risk of coastal flooding is expected to further increase in the future, as tides, surges and waves will be significantly affected by climate change and the consequent increase of extreme weather events

Summary

Introduction

Climate change is expected to have significant effects on the intensity and frequency of occurrence of extreme weather events, affecting sea levels, circulation patterns, currents and waves in oceans and seas around the world [1,2,3,4]. Coastal flooding is attributed to the combined effect of tides, surges and waves acting over a broad range of scales in space and time. There, water levels caused by tides and storm surges, combined with wave setup and onshore wave propagation, can lead to the overtopping of coastal structures and the inundation of low-lying coastal areas. This interplay between waves and water levels dictates the characteristics of the models needed for the accurate representation of related processes, while scale issues allow the use of modular modelling approaches based on varying-complexity nesting schemes and the coupling of interoperable models

Results

Discussion

Conclusion