Coasts- Case-Study's Flashcards
Talk about the Sunderbans.
The Sundarbans is a cluster of low-lying islands in the Bay of Bengal spread 40% in India, 60% in Bangladesh famous for its unique mangrove forests. The active delta region is among the largest in the world measuring about 40,000sq km and is home to an interesting ecosystem consisting of many rare and globally threatened species. Its home to over 4.5 million people making it a
rather vulnerable region.
Inputs and Outputs into the Sundarbans.
Inputs- Energy from the tides and storms comes in from the south sea and rivers.
Erosion of the sediment can provide an input as well as some deposit as the energy slows when the mangroves buffer it.
Outputs- Deposition occurs when the wave energy slows on banks or river mouths as well as where SW winds blow them into sand dunes.
Wave energy is dissipated once hitting the mangroves due to their structural nature in acting as a buffer.
Talk about Coastal Processes in the Sundarbans.
Tidal Action- Primary natural process which shapes the distinctive landscape. A Dense network of river channels flow across the clay and silt fluvial deposits which are resistant to erosion. They flow a north south direction due to the strong tidal currents and the smaller channels drain the land with each ebb tide.
Deposition- non-cohesive sediments lie sand are washed out of the delta and deposited on banks or river mouths where SW winds blow them into sand dune allowing further landforms to develop like islands and allowing mangroves forests to develop.
Talk about Landforms in the sunderbans.
Erosional: Mangrove forests collect sediment and slow down water flow helping to mitigate against erosion.
Depositional: Deltas form from the deposition of sediment carried by a river as the flow leaves the mouth Mudflats- river sediment is deposited along a rivers edge Saltmarshes- form in mudflats as silt sediments accumulate. Halophytes colonise and stabilize including mangrove trees. Sand dunes- form due to tidal action.
Talk about Mangroves.
Mangroves are tropical trees which thrive in salty, coastal waters and the interminable ebb and flow of the tide. They have thick, impenetrable roots which are vital to shoreline communities as natural buffers against storm surges. The Sundarbans stabilise the coast from tidal storm surges and has shown they can absorb 40% of a cyclones power. Their trunk and canopy can dissipate the wave energy while the roots stabilize the soil of intertidal areas.
Talk about Mitigation of hazards in the sunderbans.
- 3,500km of embankments were built to prevent flooding, however they are eventually being eroded
- Coastal Management projects aim to protect existing mangrove forests and replant areas removed to prevent against flooding and erosion.
- The government and NGO’s provide funding
Opportunities in the Sunderbans
Goods: Agriculture- aquaculture and fisheries provide the income for 93% of people and provide employment for 1.2 million.
Construction- Timber from mangrove trees are used for construction and fuel.
Honey- on average, harvesters earn around $50 daily.
Services: Ecotourism- due to the unique biodiversity and 3 wildlife sanctuaries covering over 139,000 hectares of land, ecotourism is prominent in promoting the importance of mangroves and their conservation
Talk about Challenges in the Sunderbans
Natural: Flooding- can lead to the salinisation of the soil and erosion of the land
Low lying land at risk of rising sea levels
Human: Lack of fresh water for drinking and irrigation as fresh water is diverted from rivers further upstream.
Growing population has increased the removal of mangroves for agricultural land increasing the risk of flooding and erosion.
Poor Region- 1/5 of households have access to mains electricity. This makes communication difficult.
Access is hard with few roads. This makes it hard to access healthcare and education.
Future Challenges and Adaptations of the Sunderbans.
CHALLENGES- Mangrove Deforestation as the demand for wood increases and agriculture expands.
Climate Change impact like rising sea levels and more frequent tropical storms put pressure on the region disrupting the equilibrium.
Loss of biodiversity due to habitat loss, pollution, and poaching
ADAPTATIONS- Efforts to address these challenges and ensure the preservation of ecotourism. Communities work together on initiatives like afforestation projects, sustainable resource management and community-based conservation programs to protect the natural ecosystem.
Talk about sustainable development.
In the future, numerous conservation groups and ecotourism groups will work together to help both raise awareness of the importance of the Sundarbans and help conserve and regenerate the forest to combat flooding.
Talk about Holderness
The Holderness Coast is located on the east coast of England extending 61km from Flamborough in the north to Spurn Point in the south. The Holderness coast is one of Europe’s fastest eroding at an average annual rate of around 2 meters per year.
Approximately 3 miles of land has been lost since roman times including 23 towns/villages.
There are three main settlements, Withernsea, Hornsea and Hendon including many already lost sediments. These pre-existing settlements need management as they are at risk of being destroyed.
There is as a north-easterly PWD allowing longshore drift to take place moving sediment along a coastline
Talk about inputs and outputs into the Holderness Coastal System
Inputs- Destructive waves from the north east attack the narrow beaches and headlands due to wave rarefaction- Flamborough head
Due to it being fastly eroding, large quantities of sediment (roughly 2 million tonnes every year) is eroded. In most places the land is made from glacial till deposited over 18,000 years ago which is a soft boulder rock which is eroded as an input
Outputs- Sediment transported via longshore drift gets moved out of the littoral cell near the Humber estuary.
The dissipation of wave energy occurs at the headlands due to wave
Talk about Stores in Holderness
Sediment is stored in many of the beaches along the coast including Skip sea and Hornsea.
Sediment can also be stored in landforms i.e. Spurn point spit and the mudflats behind it.
Talk about transfers in holderness
Longshore drift transports sediment due to the strong prevailing wind causing the waves to come in at an angle, the longshore currents transport the sediment south. Erosion occurs at a fast rate causing mass movement of soft rock.
Landforms in Holderness
Erosional: Flamborough Head- A resistant chalk headland with horizontal bedding planes which assist the development of wave-cut platforms and illustrate how wave erosion can produce classic erosional landforms including caves, arches, and stacks.
The Holderness Cliffs- These are made from boulder clay left by ice sheets which are retreating at an average rate of 1.8m per year due to mass movement like slumping.
Depositional: Spurn Point- large, curved spit formed at the entrance to the Humber estuary. It is 6km long and made of sand and shingle brought by longshore drift and developed a saltmarsh.
Hornsea, Mapleton and Withernsea beaches- formed by the deposition of sand and shingle which has been
