Natural Processes That Shape Our Coastline

Geography assignment

Natural Processes that shape our coastline

There are many natural processes that is affecting and shaping our coastline. Beach erosion, deposition and transportation is a big factor to our coastline. Erosion is large waves, elevated water levels, and strong storm wind, can cause serious erosion. The storm waves can move significant quantities of sand offshore. It is when large waves remove sand from the beach. (Northern beaches council, manly, 2017) Storm waves carry the sand offshore, and shorten the beach. Over time the sand is returned back to the beach by calm waves. There are also ways we have done to restore the sand and set down. (USGS, 2016) Transportation process is when the waves approach the beach at an angle, but when the water flows back into the ocean the gravity makes it return at a right angle. As this process is done over and over, it moves the sand from one end of the beach to the other. The depositional process changes the coastal environment by building layers of sand

Issues that arise at Collaroy beach from coastal development

The issues that arise from coastal development on Collaroy beach is beach erosion on the coast. This I because communities along the coast are being developed by humans with natural processes like transportation and leaves the coast with a reduced amount of sand. (Coastal Wiki, 2017). Trampling also causes erosion which is another issue that arises from coastal development as the sand dunes are very popular on the beach and have manly people walking over them, to look out, and this is found at Collaroy beach. This Bitou bush is another key issue that has occurred from coastal development. This bush has taken out all the native species and every plant has over 9,000 species and if not positioned right then all the seed fall off and will grow separately.

Here are some examples of coastal erosion from coastal development on Collaroy Beach:

This primary source photo shows erosion:

Secondary source photo:

Strategies to manage these issues

Many strategies have been implemented to reduce impacts of sea level rise and erosion. Beach nourishment is the artificial placement of sand onto the eroded shoreline. This sand just placed is then spread across the beach by natural processes. (Geoactive 2 NSW AC Stage 5 eBookPLUS) This strategy doesn’t stop beach erosion. The advantages of this is that the sand is used that best matches the natural beach material. It also has a low environmental impact at the beach. Disadvantages for beach nourishment is that the sand must come from another beach and may have an environment impact in that location. It also must be carried out on a continuous basis and therefore requires continuous funds.

A sea wall is another strategy that has been implemented to help reduce erosion and sea level rise. A sea wall is a structure placed parallel to the shoreline to separate the land area from the water. Another strategy is offshore breakwater. This is a structure parallel to the shore and placed in a water depth of about 10 meters. Advantages for the sea wall is that the waves break in the deeper water, which from that reduces the energy at the shore. Disadvantages is that is destroys surfing amenity of the coats and it requires large boulders in large quantities. The cost for the sea wall is also extremely high.

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