Search results
Results From The WOW.Com Content Network
Longshore drift from longshore current is a geological process that consists of the transportation of sediments (clay, silt, pebbles, sand, shingle, shells) along a coast parallel to the shoreline, which is dependent on the angle of incoming wave direction. Oblique incoming wind squeezes water along the coast, generating a water current that ...
Coastal zones occupy less than 15% of the Earth's land area, while they host more than 40% of the world population. Nearly 1.2 billion people live within 100 kilometres (62 mi) of a coastline and 100 metres (328 ft) of sea level, with an average density three times higher than the global average for population. [2]
While aeolian transport plays a role in the overall sedimentary budget for the coastal environment, it is paled in comparison to the fluvial supply which makes up 95% of sediment entering the ocean. [1] When sediment reaches the coast it is then entrained by longshore drift and littoral cells until it is accreted upon the beach or dunes.
Part of a coastal management system, breakwaters are installed parallel to the shore to minimize erosion. 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 ...
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.
The endless cycle of swash and backwash and resulting beach drift can be observed on all beaches. This may differ between coasts. Rhossili in Wales is a low-energy shoreline. Probably the most important effect is longshore drift (LSD)(Also known as Littoral Drift), the process by which sediment is continuously moved along beaches by wave action ...
It reduces erosion on the other, i.e. downdrift, side by reducing the speed and power of the waves striking the shore. It is a physical barrier to stop sediment transport in the direction of longshore drift (also called longshore transport). If a groyne is correctly designed, then the amount of material it can hold will be limited, and excess ...
The basic coastline in the Netherlands is a representation of the low water line of 1990. This line is used to identify coastal erosion and coastal growth and to take measures if necessary. In the Coastal Memorandum, [44] the Dutch Government decides to maintain the 1990 coastline by beach nourishment. The coastline in question is the low-water ...