4.4 Human Activity Flashcards
How does industry affect the coastline.
Industry causes humans to indirectly or directly build structures that will stop/hinder natural processes. The tourist industry may cause groynes to be built on the beach to reduce longshore drift and keep the beach how it is. This causes erosion to occur further down the beach. Chemical plants are built on the coast and can also prevent erosion, transportation and deposition. The coast is also used for transport and shipping. Dredging is also used to build on other parts of the coast, increase of erosion
How does development affect the coast.
Houses are built on the coast and headlands. This could stop mass movement or increase it. To protect the houses, sea walls are built and rock armour may be added.
How does agriculture affect the coast
Agriculture is a large industry in the UK, however farmland is considered to be of low economic value and therefore isn’t protected by seawalls, groynes, etc. Sea- level rise causes increased erosion. Farmers need to gain the most profit out of their farmland for grazing so natural habitats are reduced.
Examples of humans affecting the coastline(hard):
Groynes
Groynes will be used to reduce or stop LSD. Although this preserves part of the beach, this causes a significant amount of erosion further down the beach.
Seawall.
A sea wall is used to stop erosion along the beach. Recurved sea walls are more efficient as they rebound the wave energy back out to sea, compared to the typical sea wall where the wave will undercut the wall and erode the bottom of the wall, causing it to collapse.
Rock Armour:
Large boulders are placed on the beach, typically in front of a sea wall. They absorb the wave energy and break up the water, reducing the erosion that occurs. This can affect the area that the boulders have been taken from.
Examples of areas where human action as indirectly or directly affected physical processes
Swanage is a town near Bournemouth. It is situated in the south of the Uk and is in between two headlands, Baliards Point and Peverlls Point. The town is situated next to Swanage Bay. Groynes have been placed on the beach as it is a large tourist location, especially due to it being a jurassic coast.
What is the difference between hard and soft engineering?
Hard engineering are, usually, more expensive and impact the environment more. These include: sea walls, groynes and rock armour. Hard engineering tries to directly stop process, usually erosion, by physically stopping the process. They can be short term and only fix direct problems.
Soft engineering are, usually, less expensive and are, normally, natural processes that humans are using to maintain the coast line. They most likely use natural materials. However, they may need a lot of maintenance and that can cost a lot in the long term. They are more likely to last longer than hard engineering
Examples of humans affecting the coast(soft):
Beach nourishment:
Sediment is deposited on the beach. This builds the beach back up again. The much larger beach now can absorb more wave energy and reduce the erosion that occurs on the cliff face. This is a relatively cheap method, however winter winds can wash away the sand quite quickly. Maintenance is required often as lots of sediment is transported by the destructive waves out to the sea.
Slope Stabilisation:
Sand sits on top of clay. The sand is permeable so water easily clogs it up and makes it become very heavy. Clay is impermeable so the water is blocked and therefore the water inside the sand cannot drain anywhere. The sand may gain too much water and become too heavy for the clay and slide off. A drain is placed within the sand. This means that the water is drained away and the sand doesn’t become water-logged.
