What different kinds of coastal protection are there along the coast of Norfolk, andwhat do they depend on?

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What different kinds of coastal protection

are there along the coast of Norfolk, and

what do they depend on?

Aim

My aim is, as the title suggests, finding out what different kinds of coastal protection there are along the coast of Norfolk, and what they have an effect on.

Theory

Coastlines can be eroded or constructed. There are many different ways of doing both. Destructive waves, long shore drift and weathering (physical and chemical) are all the possible ways of destroying or moving the coastline. Constructive waves and long shore drift are the two possible ways of constructing a coastline. Although over the past few decades, there has been a new way introducing itself as a destructive force. The rise in sea level. Due to increased global warming, the sea level has risen, and therefore eroded higher levels of coastline:

Waves

The power and type of the wave has a large effect on the erosion and construction of the coastline. The more fetch a wave has, the more power the wave has when it reaches the beach. The fetch of the wave is the distance the wind has to blow on the sea/wave until it reaches the beach.

There are two types of wave. One is called Constructive, and the other is called Destructive. Constructive waves push material (sand, debris, fish etc) towards the beach and onto it, therefore increasing the length/height of the beach, but are less powerful than the destructive waves. Also, as the name suggests, destructive waves drag material from the beach back into the sea, reducing the length/height of the beach.

Long shore drift is when the waves come in at an angle, and go back out straight (perpendicular to the beach), taking the beach material with it. Long Shore Drift changes the coastline because it moves the material across the beach. This happens repeatedly to drag the material further and further down the coastline.

Erosion

Erosion is the gradual destruction of land by natural and un-natural forces, e.g. Water currents, wind, humans, acid rain etc. For the erosion of land by water, there are four types of erosion. Corrasion (abrasion) is caused by large waves hurling beach material against a cliff. Attrition is where the force of the waves causes boulders to collide underwater and break up into smaller particles. Corrosion (solution) is where acids and chemicals in the ocean gradually erode the cliff. Hydraulic Pressure is air bubbles (embedded in the cliff) being compressed by the force of the waves hitting it.

Headlands and Bays

Different types of land material eroding quicker than others form headlands and bays. Land is made up of different materials. Some a lot harder and tougher than others. It is made up of clay, sandstone, chalk and limestone. Limestone and chalk are both hard, resistant materials, and don't erode as quickly as the clay and sandstone. When the clay and sandstone are eroded, bays are formed. The resistant materials don't wear away as quick, and therefore form headlands. The following diagram (overleaf) explains how land goes from flat to having bays and headlands.
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Physical Weathering

Physical weathering can erode the coastline because at the bottom of most cliffs, there is an impermeable layer of fresh peat. When it rains, all the water from the land nearby runs down the earth and tries to rejoin the water basin, but when it can't get through the fresh peat, it all gets stored in the cliff. The cliff ends up being too heavy to stay, so it collapses. There is an example of this shown in the photo below:

Chemical Weathering

Acidic rain is the cause of chemical weathering. It rains ...

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