Factors Affecting Coastal Erosion

• The natural movement of waves constantly erodes coastline. the coast image by Anton Chernenko from Fotolia.com

  The inevitable wear and tear on coastal regions by factors such as water, storms and human activities results in erosion. Not all coastal areas erode equally, as some areas like parts of the Mississippi Delta erode easily, up to several feet per year, while rocky coasts erode merely a few inches, according to Dr. Robert H. Stewart, Texas A&M Department of Oceanography. Regardless of the factors causing coastal erosion, they all result in the shifting shape of coastline.

Currents

• Currents play a major role in maintaining the equilibrium of coastal erosion. Longshore currents flow parallel to the shoreline. As these currents move, they shift sand and other coastal debris from one beach to another, in what works as a balanced budget, according to the Florida Department of Environmental Protection. Thus, as sand erodes constantly, it usually gets replaced. Despite the precarious equilibrium of this process, it still alters the layout and shape of coastal areas.

Storms

• Stormy weather in the form of hurricanes, tropical storms and other weather systems exaggerates the normal wave action. This violence and strength of these storms cause severe coastal erosion over a short time.

Waves

• Water, particularly in the form of waves, causes coastal erosion. Hydraulic action of waves occurs as waves wash up against the face of a cliff, suppressing air in the cracks in the rocks. The resulting pressure splinters and removes bits of rock, according to Absolute Astronomy. Corrasion, or abrasive action, happens when waves pound rocky coastal areas, slowly eroding away the rock. Corrasion becomes intensified as scree, or rock debris, floating in the waves hits against rock faces.

Man-made Structures

• Man-made structures play a large role in coastal erosion, mainly because they often interrupt the natural flow of coastal currents as they take sand from one beach and deposit it on another. The construction of structures like piers, jetties and sea walls unnaturally trap the shifting sand, preventing currents from dumping that sand on other beaches. Since the currents continue to take sand, this results in an imbalance that leaves some beaches and coastal areas with less sand than others. Texas A&M Department of Oceanography reports that even those structures designed to limit erosion in the short term end up creating more erosion later down the road.

Human Activity

• In addition to the construction of structures to decrease erosion or for navigational purposes, human activity takes a toll on coastal regions. For example, destroying natural vegetation, which helps keep soil in place, increases the erosion rate, according to Dr. Stewart.