Coastal management refers to protecting coastlines from flooding and erosion. Hard engineering uses man-made structures like sea walls and breakwaters to stop coastal processes, while soft engineering works with natural systems through beach replenishment, relocating structures, and stabilizing dunes and mangroves. Both approaches aim to reduce erosion, but hard structures disrupt longshore drift while soft options are more environmentally friendly but require more maintenance.

1. Coastal ManagementCoastal Flows and Processes

2. What is Coastal Management?This refers to sea defence or coastal protectionAll three of which means protection of the beach against flooding and erosion

3. Hard EngineeringThese are methods that aim to stop the coastal processes from occurringIt involves the use of man made structures to defend against the erosive power of wavesSome structures used are gabions, groynes, re-curved sea walls, revetments and rip raps

4. Soft EngineeringThese are methods that try to work with nature to protect the coastThese focus on planning, management and changing individual attitudes towards coastal protectionBeaches or naturally formed materials are used to control or re-direct erosion processesSome coastal features used are sand dunes and salt marshes. Beach replenishment is also a form of soft engineering

5. Hard Engineering

6. Breakwaters They help to protect the coast and harbour by reducing the force of high energy waves before they reach the waves

7. They create a zone of calm water behind them

8. However, materials deposited in the zones behind them are protected but in the zones located away from the breakwater they are not, and will be eroded awayGabionsThese are large steel mesh cages filled with rocks

9. They are built into cliff faces to protect the cliff from the force of the waves

10. Though they are less costly than sea walls, the life span is shorter as they will eventually begin to rustGroynesOften described as fences built at right angles to the coastline

11. The aim is to stop the movement of material along the beach due to longshore drift

12. They are effective at reducing erosion in the area they are constructed in by causing significant build up of beach material.

13. However, they deprive areas further down the coastline of material as they stop longshore driftRe-Curved Sea WallA concrete wall curved on the underside to reflect the energy of waves

14. Very costly

15. However, they are very effective as the reflect wave energy rather than absorb it.Rip-Raps/Rock Armour Huge boulders (10 tonnes min.) stacked on beaches for use as a sea wall

16. Energy of the wave is dissipated effectively as water is let through the spaces between the boulders

17. These boulders must be big enough to withstand being eroded themselvesRevetmentWooden structures that break the force of waves

18. Beach material builds up behind them

19. Need replacing more frequently than other structuresSoft Engineering

20. Beach ReplenishmentThis process involves the transportation of sand from elsewhere to be distributed along the beachEnvironmentally, this is the preferred method as it keeps the beauty of the landscape of the beachIt is very costly and time consuming as regular replenishments are required

21. Relocation of PropertyCoastal planners are trying to protect man-made structures by relocating them and let nature reclaim the beach slowly.

22. No building of new structures is allowed in coastal areas vulnerable to coastal erosion.

23. This approachis likely to be opposed by people who want to invest in the coastal areas.Planting of MangrovesMangroves can help to trap sediments and reduce coastal erosion.However some areas with violent destructive waves may not support mangroves.The depth of the coast may also become shallower, affecting coastal transportation and port activities.

24. Stabilising DunesCoastal dunes can be found along the shore where lots of sand and strong winds exist. The winds carry and deposit the land on the coast further inland, forming coastal dunes gradually which help defend the coast from the sea.However they are very fragile and thus access points to the beach are controlled and designated.Shrubs and trees are planted to stabilise the dunes to anchor the sand.

25. Growth of Coral ReefsThey can weaken wave energy.Artificial reefs are created along the coast to help enhance fishing opportunities, serve as undersea barriers and replace damaged coral reefs.