Introduction

Coasts are high-energy environments. This mean that they are zones where there is great potential for erosion. Waves can be both constructive and destructive, with very short times scales involved.
All coasts continually change, be it with erosion, deposition, sea level fluctuation or human development. It is when the destructive waves are eroding at a substantial rate, or threatening human settlements that problems arise and human intervention takes place. This entry aims to explain the processes of erosion and also to outline it's impacts and various solutions.

Processes of Coastal Erosion

There are various types of actions that erode the coastlines. These first examples will describe the erosion of a cliff.

Hydraulic Action

Hydraulic action is the direct action from waves onto a cliff. As the water hits the cliff, it is moving at speed and has much energy. As the water tries to find somewhere to go, it will be forced into small cracks in the stone. This water, and any air it may have pushed before it, are under great pressure in this space. This can increase weaknesses in the cliff and can blast pieces of the rock from the exposed surface.

Corrosion

Corrosion