Essay on Coastal Erosion
It is a consequence of water and wind movements which leads to the formation of a variety of landforms along the coastline. Coastal erosion engages destructive waves that wear the sea. The factors termed responsible for changes in the coastal line are grouped into geomorphological and geological; biological, hydrodynamic, anthropogenic and climatic factors. Geological factors include types of sediments, the resistance, and arrangement of those sediment structures while isostasy forms the major basis of morphological processes in developing the coastal relief. Many external forces are known to influence geomorphological processes which include climatic factors like wind and rain. Climatic changes lead to the rise in sea level and a sharp reduction of the sea ice. Consequently, the erosion rates are increased along the coastal regions although dissimilar coastlines are affected at different degrees.
Notably, coastal cliffs developing from bedrocks like granite and glacial till as the case of Labrador and Newfoundland resist coastal erosion, hence remaining intact despite any climatic changes. Different ways of eroding the coastline There exist five processes that are a major cause of coastal erosion. They include abrasion, attrition, hydraulic action, corrosion and corrosion processes. Limestone cliffs are known to have a higher pH and are significantly affected by chemical weathering. The actions of the wave are also responsible for increasing the reaction rates through the removal of materials that have already reacted. Solution Solution is a process through which acidic contents available in the sea dissolve rocks such as limestone and chalk. When the rocks dissolve in sea water, they lead to erosion of the coastline.
The impacts of coastal Erosion It is vital to comprehend that coastal erosion and any other forms of coastal deposition are just natural processes that can neither be termed as good nor bad. Experts ascertain that the situation cannot change in the next two centuries. Factors that control Rates of Erosion Some factors can control the degree of erosion at a shoreline to which a shoreline including weather and climate, tides, sediment type and exposure. Sediment Type Different rocks or sediments have dissimilar resistance rates to erosion, in that they have likelihood or less likelihood to erode. The coastlines that constitute bedrocks, which are tightly packed with materials like glacial till highly resist erosion and therefore not experiencing much recession. Unlike the coasts that contain sediments that are arranged loosely like sand, gravel, and cobbles that range between 0.
meters. Climate and Weather The coastal processes are often affected by sea ice and shore fast ice developments like for example during winter within the Gulf of St. Lawrence. Ice plays a role in the erosion processes both directly and indirectly. It affects erosion directly as it freezes on the bed and plucks off the materials while it indirectly affects the erosion process via enhancing scour from the waves against the grounded ice. Enough evidence is present regarding the impacts of the rise in the sea level on the shoreline through the barrier islands that are continuing to erode not on not only the lagoons but also the open-ocean. The narrowing of the island is interpreted as an impact of the rise in the sea level since the barrier islands are capable of migrating during a rising sea.
Currently, no agreement is in establishment on why there have been frequent rises in the sea level, which is often determined through the tide records. The rise in the sea level comes with various consequences such as salt-water intrusion, flooding and also high rates of shoreline retreats. Shoreline retreats like flooding are the most critical low slope regions, for example, the Mississippi Delta region. Also, the mining process of sand for construction from river mouths and beaches is another critical source of erosion. Beach sand is easier and cheaper to obtain for constructional purposes in the coastal regions. Deceptively, the sand mining activities take place on a small scale. However, the mining activities are in terms of trucks or wagon loads.
When totaled up, it amounts to large losses of sand on the beaches. Heated debates arise from bankers, politicians, landowners, property owners, and even fisherfolks when it comes to the intensive use of the coastal areas resulting in high values of the coastal land. Consequently, challenges arise on the means of treating the coastal shoreline. A lot of the involved stakeholders resort to retreats whereby hotels and house around the region are removed leaving the coast susceptible to erosion. What they fail to comprehend is that planned retreats are unnecessary, expensive and even impossible sometimes especially in regions that are highly modified. Planting trees and establishing forests is one way of preventing the coastal erosion and the vulnerability of costs falling into the wrath of the erosion increases when trees are cleared as in the case if Vietnam, Indonesia, Sri Lanka and India.
Groynes are coastal structures that are built perpendicularly to the shoreline from the seashore direct to the sea to ensnare transportation of longshore sediments or control the currents on the longshore. They are often cheap to construct from available materials such as bamboo, wood, and rocks. However, groins have limitations such as local scour must be induced on the structures. The structures also cause down drift erosion that needs regular maintenance. Seawall structures exist in correspondence of the shoreline (parallel) hence sheltering the shores from the impacts of the wave actions. They aim to endorse natural beaches since they can as well act as artificial headlands. As compared to the offshore breakwaters, the artificial headlands are cheaper and easier to construct.
They also require little maintenance making them even more suitable. However they have limitations since they are relatively huge structures, they can lead to downright erosion and lack stability against large waves. Soft structural options The soft structural options aim at dispersing the wave energy through maintaining the natural forces and the coastal topography. The roots of the vegetation bind together the sediments facilitating building up of the dune sediments through wind baffle. Occasions when storms occur, waves can reach the dune front and accumulate sand on the beach creating storm beach profiles. While building dunes, it is a recommendation to use the combination of sand fences, mesh matting and vegetation. Coastal vegetation as a soft structural option can also be utilized to prevent coastal erosion.
Research has it that the availability of vegetation along the coastal region improves the slope stabilities. World Scientific, 2005. Dugan, J. E. et al. Estuarine and coastal structures: environmental effects, a focus on shore and nearshore structures. Polish coastal dunes: affecting factors and morphology. Landform Analysis, 22, 33-5. Shepard, Christine C. Caitlin M. Crain, and Michael W.
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