Coastal erosion and the availability of drinking water are two major coastal management issues that necessitate precise monitoring of the morphological changes to the shoreline.
Examples[ edit ] Small-scale erosion destroys abandoned railroad tracks A place where erosion of a cliffed coast has occurred is at Wamberal in the Central Coast region of New South Wales where houses built on top of the cliffs began to collapse into the sea.
This is due to waves causing erosion of the primarily sedimentary material on which the buildings foundations sit. Human interference can also increase coastal erosion: Hallsands in DevonEngland, was a coastal village that washed away over the course of a year, an event directly caused by dredging of shingle in the bay in front of it.
The California coast, which has soft cliffs of sedimentary rock and is heavily populated, regularly has incidents of housing damage as cliffs erodes. Devil's SlideSanta Barbarathe coast just north of Ensenadaand Malibu are regularly affected. The Holderness coastline on the east coast of England, just north of the Humber Estuaryis one of the fastest eroding coastlines in Europe due to its soft clay cliffs and powerful waves.
Groynes and other artificial measures to keep it under control has only accelerated the process further down the coast, because longshore drift starves the beaches of sand, leaving them more exposed.
The White Cliffs of Dover have also been affected. Fort Ricasoli in KalkaraMalta already showing signs of damage where the land is being eroded Fort Ricasolia historic 17th century fortress in Malta is being threatened by coastal erosion, as it was built on a fault in the headland which is prone to erosion.
A small part of one of the bastion walls has already collapsed since the land under it has eroded, and there are cracks in other walls as well. In El CampelloSpain, the erosion and failure of a Roman farm fish excavated on rock during the first century B.
Hydraulic action[ edit ] Hydraulic Action occurs when waves striking a cliff face compress air in cracks on the cliff face. This exerts pressure on the surrounding rock, and can progressively splinter and remove pieces.
Over time, the cracks can grow, sometimes forming a cave. The splinters fall to the sea bed where they are subjected to further wave action.
Attrition[ edit ] Attrition occurs when waves cause loose pieces of rock debris scree to collide with each other, grinding and chipping each other, progressively becoming smaller, smoother and rounder.
Scree also collides with the base of the cliff face, chipping small pieces of rock from the cliff or have a corrasion abrasion effect, similar to sandpapering. Solution[ edit ] Solution is the process in which acids contained in sea water will dissolve some types of rock such as chalk or limestone.
As the sea pounds cliff faces it also uses the scree from other wave actions to batter and break off pieces of rock from higher up the cliff face which can be used for this same wave action and attrition. Limestone cliff faces, which have a moderately high pH, are particularly affected in this way.
Wave action also increases the rate of reaction by removing the reacted material. Factors that influence erosion rates[ edit ] Primary factors[ edit ] The ability of waves to cause erosion of the cliff face depends on many factors. The hardness or inversely, the erodibility of sea-facing rocks is controlled by the rock strength and the presence of fissuresfracturesand beds of non-cohesive materials such as silt and fine sand.
The rate at which cliff fall debris is removed from the foreshore depends on the power of the waves crossing the beach. This energy must reach a critical level to remove material from the debris lobe.Why do coastal erosion areas need to be managed?
Natural protective features (beaches, dunes and bluffs) within coastal erosion hazard areas provide buffering and protection to shorelands from erosion by absorbing the wave energy of open water. View Larger Map. The Holderness Coast is one of Europe's fastest eroding coastlines.
The average annual rate of erosion is around 2 metres per year. Shorelines constantly change due to the pounding of waves that erode coastal structures. Learn about shoreline features that are formed through coastal erosion, such as wave-cut cliffs, wave-cut.
Coastal erosion at Main Beach surf lifesaving tower, Australia’s Gold Coast. Captions And Photo source: ©© Chris Ford Excerpts; The 12 Apostles is the name given to a collection of natural limestone stacks that rise up to ft (46m) from the sea off the coast of Port Campbell National Park, ph-vs.com Twelve Apostles are located along the .
Objective: To understand the processes that affect rivers. There are three main processes that affect rivers and their valleys. 1. Erosion & Weathering 2. Transportation 3. Deposition Task 1 - Turn to page 8 on the interactive OCR B textbook on your computer.
Copy the definitions of the four main processes of erosion into your book (you should remember these from your coasts work). Why do coastal erosion areas need to be managed?
Natural protective features (beaches, dunes and bluffs) within coastal erosion hazard areas provide buffering and protection to shorelands from erosion by absorbing the wave energy of open water.