Case Study: Coastal Erosion: Holderness Coast

Case Study: Coastal Erosion: Holderness Location | * Holderness is an area of the East Riding of Yorkshire, on the east coast of England. * Sub-cell that stretches from Flanborough Head to Spurn Head. | Erosion | * Fastest eroding coastline in the UK. * Rapidly retreating coastline. * At Flanborough Head, the average erosion is greater than 10cm a year. * By Mappleton, the average erosion is greater than 200cm a year. * At Spurn Head, 500000 tonnes of sand is moved by the sea each year. | Causes | * Easily eroded rock type – Cliffs are made of glacial deposits of boulder clay which is eroded through abrasion and prone to slumping. This is more easily eroded than harder rocks such as chalk. * Narrow Beaches * Causes: * Flamborough Head stops sediment from the north replenishing. It is made of chalk which dissolves rather than making beaches. * Coastal defences. For example, at Mappleton which cause human erosion. * Powerful waves – A cause of the long fetch from the Arctic Ocean and dominant wind from the North East. * Factors affecting the fetch: * Currents – or swell – which circulate around the UK from the Atlantic and into the North Sea. The Atlantic fetch is 5000km or more, and its currents add energy to waves in the North Sea. Therefore, there are often powerful destructive waves along this coastline. * Low pressure weather systems passing over the North Sea are often intense, and locally produce very strong winds and waves. * The sea floor is deep along the Holderness coast. Therefore, the waves reach the cliffs without first being weakened by friction with shallow beaches. * Mappleton is more easily eroded as it lies upon an unconsolidated till. | Impacts | * Property prices have fallen. * 80000 m2 of good farmland is lost each year. * Since Roman times the sea along this part of the coast has advanced 3km. * Housing and farmland are at risk * 29 small