What are the coastal management techniques; hard engineering, soft engineering and managed retreat? What is rock armour? How do groynes work? What is beach nourishment?
This is the forty-first video for the AQA GCSE 9-1 Geography course, and the eighth video of the Physical Landscapes topic.
The Physical Landscapes Playlist:
» [ Ссылка ]
Follow me on all platforms:
» [ Ссылка ]
Do you have a video suggestion?
» [ Ссылка ]
Video Script:
Coastal management techniques can be grouped into 3 main strategies: hard engineering, soft engineering and managed retreat.
Hard engineering involves using artificial structures to try to control coastal processes.
Groynes are wooden or rock structures built out from the coast at right angles to the sea. They work against longshore drift, trapping sediment to prevent it from being carried further along the coast. This helps to build up beaches, which act as a buffer to the sea, reducing wave damage. They are not too expensive and the wider beaches can attract more tourists. However, they have a major disadvantage. Since they work against longshore drift, beaches further along the coast are starved of sand which can cause increased rates of erosion. Some people also think they look unattractive.
Sea walls are concrete walls placed at the foot of cliffs or at the top of a beach. They are often curved to reflect wave energy back into the sea. They are very effective and also typically have promenades on top, making them attractive for tourists. However, they are very expensive and look unnatural.
Rock armour is large boulders placed at the foot of a cliff. The rocks break waves, absorbing their energy which protects the cliffs behind them. They are relatively cheap and can be used for fishing however they have a few disadvantages. The rocks typically come from elsewhere, including other countries, which means they can look obtrusive as they do not fit in with the local geology.
Gabions are wired mesh cages that are filled with rocks. They act as a buffer to the sea, absorbing wave energy in a similar manner to rock armour. They are cheap, but they are not as strong as rock armour and look unnatural. Damaged gabions can also be dangerous to people and wildlife.
Instead of working against the sea, soft engineering techniques work with natural processes.
Beach nourishment is where sand is added to an existing beach to build it up. The sediment is usually sourced locally so that it blends in with the existing beach. This technique is cheap and enlarging beaches attracts tourists, but constant maintenance is needed.
Dune regeneration involves supporting and protecting sand dunes. Planting marram grass can help stabilise the dunes and allow sand to accumulate. Fences can also be used to either artificially create new dunes or protect existing dunes from people trampling on them. This method is relatively cheap, looks natural and supports local ecosystems. However, fencing off areas to the public can be unpopular.
The final strategy is managed retreat. Managed retreat is where the sea is allowed to flood low-lying areas. This typically occurs where the value of the land is low, such as farmland. It is cheap and sustainable and also creates saltmarshes. These are valuable ecosystems which support a variety of species and they also act as a natural buffer to the sea. However, this method can be very controversial - would you want to part with your land if you lived by the coast?
--
GCSE Geography
12/05/2023
Keducate
