'The Holderness coastline is a 61km stretch of coastline that extends from Flamborough Head in the north to Spurn Head in the south. The Holderness coastline is the fastest eroding coast in Europe, and one of the fastest in the world. Why does it erode so rapidly?
It erodes rapidly because the cliffs are made up of soft clay (called ‘boulder clay’) and sand. The clays and sands are unconsolidated which means they have not been compressed and hardened. The cliffs are not able to resist the force of the waves hitting them and frequently collapse. The sea then removes the debris and starts to attack the cliffs again. In this way, the cliffs recede (i.e. move inland) at a rate of around 2 metres a year.
Geographer’s estimate that about 7,645,000 m³ of material has been lost from the Holdeness coast in 100 years. As the cliffs recede, villages close to the sea are under threat and historical records show that 29 villages have been taken by the sea since Roman times. 'Each year approximately 1 million m³ is eroded from the Holderness coastline and moved southwards. Only 3% of this reaches Spurn Head. The rest is either deposited in deep offshore areas (known as 'sinks') or is carried across or into the Humber estuary
Around Flamborough Head, the cliffs are made up of chalk which is much more resistant. These cliffs have not receded as far as the clay cliffs which is why Flamborough Head forms a headland. There are two other factors that help bring about coastal erosion in the area.
(i) The weather: In winter there are frequent storms which produce stronger waves and higher sea levels. The rain also saturates the clay cliffs and they either slump or flow.
(ii) The second factor is the waves that attack the coastline. The dominant wind and thus wave direction is north-east. These waves have, therefore, a long fetch which causes very destructive waves.
The approach of the dominant waves from the north-east causes longshore drift to move the material southwards. At the end of this stretch of coast where it meets the Humber, is a spit called Spurn Head. Each year it is estimated that 500,000 tonnes of material a year is moved towards the spit.
Various strategies have been adopted along the coastline to stop or slow down erosion.
Hornsea is dependent on tourism and recreation and has a small fishing industry. Groynes have been used to protect the beach and behind that there is a sea wall. The authorities have also used rock armour (which is also called ‘rip rap’) to protect the esplanade behind it. The strong coastal defences have successfully reduced coastal erosion but have increased it to the south of the town.
Mappleton consists of only about 50 properties but suffers from a rate of erosion of 2m a year. It needs to be defended, despite being a small hamlet, because the B1242 is a vital road (and is only 50m from the cliff at one point) and it would more expensive to re-route it than it is to protect the stretch of coast between it and the sea.
In 1991 two rock groynes and a rock revetment were constructed (at a cost of £2 million), and as a consequence a substantial beach has accumulated. The groynes have, however, affected the movement of material down the coastline.
The scheme has been moderately successful as the houses and the road seem to be safe. The cliffs are however showing signs of slumping. Skipsea
At Skipsea, the authorities have placed cages filled with pebbles called ‘gabions’ along the sea wall to absorb some of the wave energy.
Easington Gas Terminal is owned by British Gas and together with nearby Dimlington Gas Terminal provides 25% of Britain’s gas. The rate of erosion is 1 .8m a year.
The defence of Easington presented huge problems as it is so close to Spurn Head which is a habitat for many species of bird and other fauna. The concern was that if they had built groynes this would have prevented sediment reaching the…