Search results
Results from the WOW.Com Content Network
Coastal erosion is the loss or displacement of land, or the long-term removal of sediment and rocks along the coastline due to the action of waves, currents, tides, wind-driven water, waterborne ice, or other impacts of storms.
Hydraulic action, most generally, is the ability of moving water (flowing or waves) to dislodge and transport rock particles.This includes a number of specific erosional processes, including abrasion, at facilitated erosion, such as static erosion where water leaches salts and floats off organic material from unconsolidated sediments, and from chemical erosion more often called chemical ...
On beaches where longshore drift threatens the erosion of beach material, smaller structures on the beach may be installed, usually perpendicular to the water's edge. Their action on waves and current is intended to slow the longshore drift and discourage mobilisation of beach material. In this usage they are more usually referred to as groynes.
Erosion and changes in the form of river banks may be measured by inserting metal rods into the bank and marking the position of the bank surface along the rods at different times. [23] Thermal erosion is the result of melting and weakening permafrost due to moving water. [24] It can occur both along rivers and at the coast.
Examples of hard engineering include: Groynes – Low walls constructed at right angles to retain sediments that might otherwise be removed due to longshore drift.These structures absorb or reduce the energy of the waves and cause materials to be deposited on the updrift side of the groyne facing the longshore drift.
Without the constant presence of water, stacks also form when a natural arch collapses under gravity, due to sub-aerial processes like wind erosion. Erosion causes the arch to collapse, leaving the pillar of hard rock standing away from the coast—the stack. Eventually, erosion will cause the stack to collapse, leaving a stump.
Wave pounding is a force of erosion along coast lines. The effects of wave pounding are influenced by wave shape, ocean chemistry, rock type, and morphology of the coastal landscape. There are three different types of waves to consider in this process: spilling, plunging, and surging waves.
After the wave breaks, it becomes a wave of translation and erosion of the ocean bottom intensifies. Cnoidal waves are exact periodic solutions to the Korteweg–de Vries equation in shallow water, that is, when the wavelength of the wave is much greater than the depth of the water.