Coastal Hard Engineering
- Coastal management is essential to build resilience in coastal communities around the world
- Climate change, increase tropical storm intensity, more frequent storm surges and sea level change are increasing the rates of coastal erosion and flooding
- These hazards need to be adapted to, as they are already happening in many places
- Preventing coastal erosion through hard engineering is generally effective but it is very expensive
- Hard engineering can also often be unsightly
- There are lots of different hard engineering strategies, to decide which is most appropriate in a particular area a cost benefit analysis must be carried out
- Some areas are left with no protection because the costs are deemed to outweigh the benefits
|
Structure |
How it works |
Advantages |
Disadvantages |
|
Groynes |
Structures built perpendicular (at right angles) to the shore. Sediment is trapped as it is transported by longshore drift. The beach builds up which absorbs wave energy |
Not as expensive as other hard engineering structures Builds up the beach which improves tourist potential |
Causes sediment starvation further along the coast Can be unattractive Need lots of maintenance to ensure sediment isn’t getting through any holes or cracks |
|
Sea Walls |
Walls with a curved or stepped surface that absorb and reflect wave energy |
Highly effective Can have tourism benefits as walkways are created |
Very expensive to build and maintain - £6000 per metre Are ugly and intrusive to the landscape |
|
Rip Rap/ Rock armour |
Large concrete or granite boulders at the foot of a cliff. The spaces in between the boulders cause waves to bounce between many surfaces, reducing the energy of the wave |
Cheaper than sea walls Used for recreation such as fishing |
Dangerous when people are on them Rocks from elsewhere are intrusive to local geology |
|
Revetments |
A sloped or ramp-like structure that breaks up wave energy |
Cost-effective compared to other hard engineering strategies |
Need lots of maintenance Unnatural looking Slopes are dangerous |
|
Offshore Breakwater |
Rock barrier a little out to sea from the shoreline. This breaks the waves and dissipates their energy before they reach the coast. |
Effective Away from the beach so does not disrupt tourist potential |
Can create a navigation barrier in harbour areas |
Exam Tip
You need to be comfortable evaluating hard engineering strategies against each other and against other methods like soft engineering using examples.
