4.5 Challenges For Coastline Flashcards
Why is sea level rising
- water being warmed which expandes as it heats
- inland ice melting of glaciers and ice sheets
- climate change warming the earth and the atmosphere
How bad will sea level get and how will it effect different places around the world?
Sea levels have already risen in the english channel by 12cm in the past 100 years. In Bangladesh if the sea level would rise by 1.5m around 17million people would be effected by the rise and if it rose by 1.2m most of the Maldivian islands would be submerged by water. In Britain sea level would have to rise by 2m and over 400,000 homes would be effected. If the climate keeps on getting hotter then the Antarctic ice sheet may melt and add 61.1 metres to the sea level.
How will sea level change effect erosion/deposition?
- Cliffs would erode faster due to wave cut notch expanding.
- Soft rock coastline would erode faster due to more storms and high sea levels. This would erode land meaning houses would be gone.
- Beaches, spits and bars would be harder to form and erode more easily.
- Places such as the Studland peninsula in Dorset would be eroded making many public places at threat.
How will climate change effect storm frequency, storm surges and intensities?
There would be more storm surges with powerful movements of water and the wind being also very powerful. Waves would rise more due to less pressure on the earths surface making it worst for coasts. There would be more storms and be more powerful than before. Massive flooding and houses being damaged.
How will storm and storm surges affect people and the environment?
People could die and homes could be flooded or damaged. Evacuated from homes and possessions could be lost or damaged. Fresh water areas could be washed with salt water, farmland and bird sanctuaries could be affected.
How do groynes and sea walls work?
Groynes stop longshore drift moving sediment along the coastand sand builds up the beach. Advantage- it builds up beaches and good for tourism. Disadvantages- erosion is worst down drift and maintenance costs a lot due to wood rotting.
Sea walls reflect wave energy out to sea so the waves don’t go to land. Advantages- recurved shape focuses energy out to sea. Disadvantages- can make beach access difficult and ugly.
How does beach replenishment and slope stabilisation work?
Beach replenishment adds sediment to a beach and builds up the beaches height which then absorbes the waves energy. Advantages- looks natural and attracts tourists to beach and is cheap. Disadvantages- Winter storms transport sediment away and replacement of sediment needed often.
Slope stabilisation reduces mass movement due to drainage pipes being placed under vegetation and reducing water pressure. Advantages- reduces mass movement and keeps cliffs on place and is safer for beach users. Disadvantages- difficult to instal
Difference between soft and hard engineering
Hard engineering uses man made materials like concrete. It stops natural processes like erosion and involve a lot of construction and disruption.
Soft engineering uses natural materials like sand. Work with natural processes and does not involve a lot of construction and only sometimes needs a lot of engineering. This is the best option as it looks better and does not disrupt as much.
What is strategic realignment and what areas may be left to erode?
Less value places are left without defences and let natural processes happen at the shoreline. But we defend and protect areas that are important and gives a lot of money. It does not cost a lot as not everywhere is protected.
Why are ITCM schemes a sustainable form of coastal management?
This looks at the whole coastline rather than just parts of it. See which areas should be left to erode and which should be defended. There would not be as much management as not all the coastline would be defended. It easily protects areas and does not cost much in the longterm.
