Beach Erosion

(Coastal Erosion)


When a major storm or natural disasters hits, for example, a hurricane, can cause a major effect to our beaches; especially living on the coast. Beach erosion occurs naturally when sea level rises, and strong waves hit the beach. This causes flooding on the beach. The rocks, soils, and sand on the coast is worn or washed away causing the area to lose its “beach”. Beach erosion can be a major disaster in some cases; some beaches are vanishing due to beach erosion.

Humans can actually do a lot to help beach erosion. Different techniques can be used, and structures can be built and put in place to save the area. Before and after a storm or major disaster, people gather and work to protect our beaches; especially after. If no action was done to our beaches and we let nature take its course, beach erosion would jump drastically; not in a good way. Continuing the way we live, we might lose our beaches.

Types of structures

There are two basic types of coastal erosion control structures. The first type is shoreline hardening structures that protect upland property. Examples of hard structures are seawalls, revetments and bulkheads. The second type is sand retention structures that trap and retain sand. Examples are groins and breakwaters.

Seawalls and revetments, by design, are placed along the back shore as a means of absorbing or reflecting wave energy and preventing further recession of the uplands. Sand on the seaward side of such structures remains subject to erosion and can be lost, leaving no beach.

Sand retention structures, by comparison, are placed across the beach or nearshore so as to modify waves and currents, the primary processes that control sand transport, the form of the beach and the erosion or accretion of the beach.

Beach renourishment can be used to slow down the process of beach erosion. Beach renourishment describes a process by which sediment, usually sand, lost through longshore drift or erosion is replaced from other sources. This is not a long term solution because sand that is brought in from another source can be washed away from waves or moved down the shoreline. A pro from renourishment is that it protects the public and structures behind the beach because it acts as a strong buffer. A con from renourishment is that it is very expensive and new sand that is added to the beach can bury marine life that is residing underneath the sand. Another con is that renourishment can take a long time to be completed and must be completed every five years or sooner in order to be successful.

Niche and Habitat

Beach erosion happens all along the shoreline of all beaches. See the three pictures below.

There are five main processes which cause coastal erosion. These are corrasion, abrasion, hydraulic action, attrition and corrosion/solution.

Corrasion is when waves pick up beach material (e.g. pebbles) and hurl them at the base of a cliff.

Abrasion occurs as breaking waves which contain sand and larger fragments erode the shoreline or headland. It is commonly known as the sand paper effect.

Hydraulic action is when waves hit the base of a cliff and air is compressed into cracks. When the wave retreats the air rushes out of the gap. This action often causes cliff material to break away.

Attrition is when waves cause rocks and pebbles to bump into each other and break up.

Corrosion/solution is when certain types of cliff erode as a result of weak acids in the sea.

These processes cause shorelines to become weak which causes the base of shorelines to erode away first. This can cause shorelines to appear to have cliff characteristics, however, the shoreline is weak and can eventually erode further up the shoreline. When shorelines become to weak, or erode further up the coastline, this is when safety becomes an issue for residents, and visitors because when the shoreline is weak, the structures on the shoreline an become weak and collapse.


Evolutionary History

Beach erosion is something that has been happening all through out history, but has gotten worse over time. In the past, beach erosion was not a threat. Now that it is happening everyday, people are aware and more concerned over it. Sea level, surprisingly, used to be somewhat stable. As people began to make home closer to shore, beach erosion became a huge threat. A few years back, people did not have the technology like we have today to maintain or stop the effects of beach erosion. This made life much harder protecting our beaches. People had to make due with what they had on land, such as clay dikes, wood piles, fascinates, and rock revetments. Today, there are many other techniques we can use to help beach erosion on our beaches.



Environmental Impacts/ Conservation.

Humans can hurt and help our beaches. Beach erosion is a natural process, but humans play a big role in how fast beach erosion can happen. Humans are moving closer to our beaches to build homes. This leads to destruction of the dune grasses and disturbance of coastal land forms; this causes an increase of erosion and the movement of beach materials that is there. When people are patrolling the beaches by using cars, carts, or even walking adds to the erosion of the shoreline due to the constant destroying of plant roots and also animals that are living on beach. Humans also play a role in sea level changes in our waters. Humans are pumping ground water, salt brines, and petroleum resources from coastal environments into our waterways which is leading to higher water levels in areas. Greenhouse gases are rising also due to humans. Humans are using so many factories and chemicals, it is hurting the air and environment.This is causing ice sheets to melt and is slowly raising sea levels world wide.

Humans can help beach erosion by building structures or using other techniques and putting them in place. Using structures or techniques can promote our beaches and save what is there. These structures and techniques may not save our beaches, but they will slow the process down and cause our beaches to stay as healthy as they can.

Friends or Foes?

Many organism exists within and on our beaches. Our beaches are a home to many animals and is a recreational area for humans to gather on. Beach erosion is harming our beaches and for those who live on and around it. Beach erosion causes people, who live near the shoreline, to relocate and, most importantly, animals are losing their homes due to erosion because the coast is receding. As the coast recedes, it is driving the animals out and away because they have no where to live safely. This leads to animals dying because they leave and find a new home where they can not survive.

Three animals that rely on the beaches for activities, such as for laying eggs, are loggerhead sea turtles, the red knot and the piping plover.


Web Resources for Audience to Explore

This video shows a demonstration of what happens on our beaches when beach erosion happens. Link: https://www.youtube.com/watch?v=PIwA9fkK3cI

Want to learn more about what causes beach erosion? Link: https://www.scientificamerican.com/article/what-causes-beach-erosion/#:~:text=According%20to%20Stephen%20Leatherman%20(%E2%80%9CDr,inlets%2C%20tidal%20shoals%20and%20bays.

Want to learn more about how severe storms and hurricanes contribute to beach erosion? Link: https://coastal.er.usgs.gov/hurricanes/coastal-change/beach-erosion.php

Want to learn more about solutions for coastal erosion? Link: https://nwdistrict.ifas.ufl.edu/nat/2017/08/25/coastal-erosion-a-problem-with-new-solutions/

Visit National Geographic for more information on erosion across the country. Link: https://www.nationalgeographic.org/encyclopedia/erosion/

Resources

Bennett, A. (2016). What is coastal erosion? Retrieved June 21, 2020, from http://www.geography.learnontheinternet.co.uk/topics/coastal_processes.html

Environmental Benefits of Beach Renourishment. Retrieved June 22, 2020, from https://hiltonheadislandsc.gov/projects/beachrenourish/2016beachrenourish/environment.cfm

Pranzini, E. Coastal erosion and shore protection: A brief historical analysis. J Coast Conserve 22, 827–830 (2018). https://doi.org/10.1007/s11852-017-0521-9

Reintroducing Structures for Erosion Control on the Open Coasts of America . (2011, January). Science and Technology Committee American Shore & Beach Preservation Association. Retrieved June 22, 2020, from http://asbpa.org/wpv2/wp-content/uploads/2016/04/Reintroducing-Structures-for-Erosion-Control_FINAL.pdf

U.S. Climate Resilience Toolkit. (2019, September 13). Retrieved June 21, 2020, from https://toolkit.climate.gov/topics/coastal-flood-risk/coastal-erosion

Watson, J. (2008, September 04). Coastal Change. Retrieved June 21, 2020, from https://pubs.usgs.gov/circ/c1075/change.html