Coastal Management
- 1. By Laurence Kobrock Coastal Management / Protection
- 2. What is Coastal Management? Coastal management is defence against flooding and erosion and techniques that allow erosion to claim land.
- 3. Why do we do it? In the case of humans, we use the coastline for agriculture, for fishing, for industry and power generation, for transport routes and for land upon which to live. However, a lot of these land uses are incompatible with the fact that the coastline is constantly changing. Erosion processes remove land from some parts of the coastline, whereas deposition processes create new land in other places. In addition, the fact that the sea level is rising locally and globally could add to these erosion and deposition problems whilst also removing land from use at the coastline.
- 4. What are Hard / Soft measures? Hard • Hard engineering involves the building of entirely artificial structures using various materials such as rock, concrete and steel to reduce or stop the impact of coastal processes • Ex: – Groynes – Sea Walls Soft • Soft engineering options are often less expensive than hard engineering options. They are usually more long-term and sustainable, with less impact on the environment • Ex: – Beach Nourishment – Due Regeneration
- 5. Recurved Sea Wall • Massive, made of rocks or concrete, used to absorb waves. Some types can act as Baffles
- 6. Advantages • Very effective • Reasonably long lifespan • Traditional solution • Can prevent coastal flooding in some areas Disadvantages • Very costly • Visual pollution • High maintenance cost
- 7. Groynes • Rock or wooden types, hold beach material threatened by LSD erosion
- 8. Advantages • Low capital costs • Repaired pretty easily Disadvantages • Need regular maintenance • Cause scour downdrift • Visual pollution
- 9. Rip Rap (rock armour) • Very large rocks in front of sea walls to absorb waves
- 10. Advantages • Very effective • Prevents large-scale undermining Disadvantages • Expensive • May move in severe weather
- 11. Off shore reefs • Reduces power of waves offshore
- 12. Advantages • Can be built of waste materials • No visual pollution Disadvantages • Possible ecological impacts • May not work at large scale
- 13. Toe armouring
- 14. Advantages • Low maintenance costs • 30-50 years effectiveness Disadvantages • High construction costs • Disruption to ecology
- 15. Revetments • Made of concrete or wood. • Reflects waves rather than resist them
- 16. Advantages • Cheaper than sea walls • Traditional solution to protect valuable resources, densely populated areas an high- risk property Disadvantages • Costly • Do not cope well with very strong waves • Visual pollution
- 17. Gabions • Wire cages holding smaller rocks • Bank/cliff stabilisation
- 18. Advantages • Cheaper than revetments • The rocks absorb a moderate amount of wave energy Disadvantages • Relative small scale solution • Visual pollution
- 19. Cliff Stabilisation • The drainage of excess rainwater by terracing, planting and wiring to keep the cliff in place
- 20. Advantages • Cost effective Disadvantages • A moderate amount of visual pollution • Effects the ecology of the cliff
- 21. Cliff drainage • Removal of water in order to prevent landslides and slumping
- 22. Advantages • Cost effective Disadvantages • Drained cliffs can dry out and lea to collapse • Has effects on the ecology • Visual pollution
- 23. Beach nourishment • Sand pumped or transported to replace losses by LSD
- 24. Advantages • Looks like a ‘natural looking’ process Disadvantages • Expensive • Will erode soon • Ecological effects
- 25. Natural (do nothing) • Land no longer worth protecting. Lets the sea erode the land with no intervention
- 26. Advantages • Saves expenditures on defence • No impact on nature and ecology Disadvantages • May allow problems to get worse • Loss of land