Why the coast is eroding so rapidly. Link to geology, wave energy, and longshore drift. A map of the coastline with key places and processes labelled eg geology. How erosion is affecting people along the coast.
Why the coast is eroding so rapidly. Link to geology, wave energy, and longshore drift.
A map of the coastline with key places and processes labelled eg geology.
How erosion is affecting people along the coast.
What is Spurn Point and how was it formed
What is being done to slow the erosion of the cliffs? Sea walls, groins, boulders -but not everywhere.
The Holderness Coast is one of Europe’s fastest eroding coastlines. The average annual rate of erosion is around 2 metres per year. This is around 2 million tonnes of material every year. Under lying the Holderness Coast is bedrock made up of Cretaceous Chalk. However, in most place this is covered by glacial till deposited over 18,000 years ago. It is this soft boulder clay that is being rapidly eroded.
There are two main reasons why this area of coast is eroding so rapidly. The first is the resuly of the strong prevailing winds creating longshore drift that moves material south along the coastline. The second is that the cliffs are made of soft boulder clay which erodes rapidly when saturated.
The Holderness Coast is a great case study to use when examining coastal processes and the features associated with them. The area contains ‘text book’ examples of coastal erosion and deposition. The exposed chalk of Flamborough provides examples of erosion, features such as caves, arches and stacks. The soft boulder clay underlying Hornsea provides clear evidence of the erosional power of the sea. Mappleton is an excellent case study of an attempt at coastal management.
This article describes how different kinds of human interventions may affect coastal erosion. Natural causes of coastal erosion are discussed in another article. Most of the content of this article is drawn from Mangor et al. 2017.
Coastal structures interfering with the littoral transport are the most common cause of coastal erosion. The presence of the structure has a series of effects (see Coastal Hydrodynamics And Transport Processes and Littoral drift and shoreline modelling):
The structures, which may cause this type of erosion, are:
The accumulation and erosion patterns adjacent to coastal structures depend among other things on:
The typical impact on coastal processes and related shore erosion problems for different types of structures will be discussed briefly in the following. A more comprehensive description of the structures and their function is given in Hard coastal protection structures. The relation between structures and coastal erosion is also described in the articles: Dealing with coastal erosion, Port breakwaters and coastal erosion and Accretion and erosion for different coastal types.