Gravel Beaches

Introduction

Gravel beaches are widespread around the world, including the USA, Canada, Japan, Argentina, New Zealand and the wave dominated coastlines of Northern Europe . In the UK, about one third of the coastline is protected by such beaches .

In coastal defence schemes, considerable use is made of coarse-grained (gravel) sediment to replenish eroding beaches, often in conjunction with structures such as rock or wooden groynes or offshore breakwaters. This is because such beaches are known to be an efficient form of natural coastal defence . Two examples from the UK are those at Sidmouth, Devon and Elmer, West Sussex.

Research into the particular characteristics of gravel beaches and their engineering analysis is relatively new, with much of the progress being made recently. In the 1990’s small scale experimental measurements and early field studies lead to the subsequent development of parametric models for profile prediction, longshore transport and the stability of barrier beaches. Since 2002, two major large scale experimental studies and some new comprehensive field studies have been undertaken. Since that time, good progress has also been made in process based numerical modelling systems for long and cross shore transport.

The emphasis of the article is to present in a clear and concise manner the most relevant concepts, basic understanding and insights into the behaviour of gravel beaches, to provide a summary of the available engineering analysis techniques and modelling approaches and to provide guidance to further reading and a list of the most relevant references to work carried out since 1990.