Coastal Management - Hard Engineering
Geography: Cambridge International GCSE (2027 Exams), topic 2.3.3
Coastal Defences - Hard Engineering
Hard engineering strategies to protect coastlines use man-made constructions to protect the coastline from the sea's erosion and destructive waves. Hard engineering can also be used to stop the sea or rivers from flooding areas. Examples of hard engineering strategies are:
,w_800.jpg)
Sea walls
- Sea walls are made out of materials that block waves.
- Making them out of hard rock or materials like concrete means that they are more resilient and last longer.
- Their shape can be designed to reflect a wave's power back out to sea, instead of being absorbed by the sea wall head-on.
- Sea walls can protect promenades from flooding and can reduce coastal erosion.
- Sea walls cost a lot of money and have to be built all along a town's coastline to protect the town.
Rock armour (riprap)
- Rock armour is simply a pile of rocks or boulders.
- The rocks absorb some of the pressure and energy transferred by waves.
- Enormous waves can remove the boulders, but they are a very cheap form of coastal protection.
Gabions
- Gabions are wire cages full of boulders and rocks. that are filled with rocks.
- The gabions absorb some of the pressure and energy transferred by waves.
- This leads to less erosion, but the wire in the cages is corroded over time.
Groynes
- Groynes are fences that stick out at 90o to the coast.
- Groynes stop the process of longshore drift by trapping material against the fence.
- Groynes create wide beaches, which are better for protecting the coastline from erosion and floods.
- Building fences is also cheap.
Test yourself on Coastal Management - Hard Engineering
What are the disadvantages of sea walls?