Coasts Case Studies Flashcards
where is the Sundarbans located?
in the bay of bengal spanning 60% in Bangladesh and 40% in India
how large is the sundarbans?
40,000 sq km making it the largest mangrove forest
how many people live in the Sundarbans?
4.5 million, making it a vulnerable region
Name the three endangered species found in the Sundarbans
Royal Bengal Tiger, Estuarine Crocodile, Indian Python
what are the key inputs into the Sundarbans system?
Tidal energy from the bay of bengal
sediment supply from the three rivers, Ganges, Brahmaputra, Meghna
what are the main outputs of the system? Sunderbans
deposition at the river mouths and marks
wave energy dissertation by mangroves
What is the primary natural process shaping the sundarbans
tidal action- as strong tidal currents shape the river channels
how does deposition shape the Sundarbans?
sand is washed out of the delta and deposited on the river mouths
winds create sand dunes, supporting mangrove growth
How do mangroves help prevent erosion?
they trap sediment, stabilise soil and buffer storm surges
name three depositional landforms in the subarbans
deltas, mudflats, salt marshes
How much cyclone energy can mangroves absorb?
40% of the cyclone energy
what percentage of people in the sundarbans rely on agriculture and fishing?
93%
how many people are employed by fisheries?
1.2 million
what is a major ecotourism attraction in the Sundarbans
Wildlife sanctuaries covering 139,000 hectares
How much can honey collectors earn daily?
$50
what are the major natural challenges (sunderbans)
flooding and salinisation of soil, low lying do vulnerable to rising sea level changes
what are the two major human challenges?
deforestation for agriculture, increasing flood risk
limited access to fresh water due to upstream river diversions
what percentage of houses lack electricity?
20%
how many km of embankments were built to prevent flooding?
3,500km- eroding overtime
what are two ways the government and NGO’s help during cyclones?
cyclone shelters
early warning signs
how are communities adapting to challenges?
afforestation projects
sustainable fishing and farming practices
education programs
how does ecotourism and conservation groups help the sundarbans?
raise awareness, support conservation and regenerate mangroves
Where is the holderness coast located?
on the east coast of england stretching 61km from flamboroigh head to spurn point
how fast is the holderness coastline eroding?
2m per year on average, Europes fastest eroding coastline
how much land has been lost since roman times
3 miles off land, 23 towns and villages
name three key settlements on the holderness coastline
Hornsea, Withernsea, Mappleton
what are the main inputs from the holderness system?
destructive waves from the northeast
2 million tonnes of sediment eroded annually
soft boulder clay deposited over 18,000 years ago is very easily eroded
what are the key outputs from the system?- holderness
sediment transported by LSD toward the humber estuary
wave energy dissipated at headlands like flamborough head
what are the main marine processes at work on the holderness coastline
hydraulic action and abrasion eroding hard chalk
LSD moving sediment southwards
deposrooon forming beaches at spurn point
what are the key weathering processes
mass movement, slumping due to weak, waterlogged boulder clay
rotational slop causing cliff collapses
name a key erosion landform on the holderness coast
flamborough head- a resistant chalk headland with wave cut platform, caves, arches ext
what are the characteristics of the holderness cliffs
made of soft boulder clay
retreating at a high rate
name a major depositional landform on the holderness coast
spurn point- 6km long curved slit at the mouth of the humber estuary with salt marshes behind it
how does geology influence erosion at holderness
cretaceous chalk at flamborough head is resistant to erosion
boulder clay is soft and easily eroded by rainwater and waves
now do beaches influence erosion rates
holderness have naturally narrow beaches meaning less protection from wave energy
how does wind and wave direction impact holderness
strong prevailing wind cause LSD moving south
destructive waves increase erosion
What are the Sundarbans?
The Sundarbans are located in SW Bangladesh and E India, on the delta of the Ganges, Brahmaputra, and Meghna rivers on the Bay of Bengal.
What is significant about the Sundarbans?
It is part of the largest mangrove forest in the world, protected as a National Park.
What is the geographical nature of the Sundarbans?
The land is flat and low-lying, inter-seated by thousands of channels.
What is the state of the coastal system in the Sundarbans?
In its natural state, the coastal system is in a state of dynamic equilibrium, with fluvial sediment deposited by rivers allowing the growth of mangrove forests.
What role does tidal action play in the Sundarbans?
Tidal action is the primary natural process shaping the coastal landscape, with a dense network of river channels flowing across clay and silt deposits.
How does deposition occur in the Sundarbans?
Non-cohesive sediments are washed out of the delta and deposited on banks or at river mouths, forming new islands and allowing vegetation to establish.
What are mangrove forests?
Mangrove forests collect sediments and slow down water flow, helping to mitigate against erosion.
How are deltas formed?
Deltas are formed from the deposition of sediment carried by a river as it enters slow-moving water, losing power to support sediment transport.
What are mudflats?
Mudflats are huge quantities of river sediment deposited along a river’s edge, slowing the river’s velocity.
What are salt marshes?
Salt marshes form in mudflats as silt sediments accumulate, with halophytes like mangrove trees stabilizing the mudflat.
How are sand dunes created?
Sand dunes are created as constructive waves wash large quantities of sand ashore, with strong winds blowing sand onto the dunes.
What opportunities do the Sundarbans provide?
The Sundarbans are home to 4 million people and provide products, services, and opportunities for development.
What economic benefits do the Sundarbans offer?
The flat, fertile land is ideal for growing crops, and the mangrove ecosystem provides fish, crabs, and timber.
What services do mangrove forests provide?
Mangrove forests act as a natural defense against flooding, absorbing excess water and binding soil to prevent erosion.
What are the development opportunities in the Sundarbans?
There are opportunities for tourism and infrastructure development, such as a proposed power plant.
What risks do residents of the Sundarbans face?
Residents face a lack of fresh water, increased flooding risk, rising sea levels, and poor access to electricity and infrastructure.
What is resilience in the context of the Sundarbans?
Resilience refers to the ability to cope with environmental challenges, such as improving access to clean water and building better infrastructure.
What adaptation strategies are being implemented in the Sundarbans?
Strategies include growing salt-resistant rice, building houses on stilts, and promoting sustainable tourism.
What mitigation efforts are being made in the Sundarbans?
Efforts include building embankments, protecting mangrove forests, and providing funding for cyclone shelters and early warning systems.
What is the rate of sea level rise in the Sundarbans?
The Sundarbans is experiencing a sea level rise of 3-8mm each year.
What causes sea level rise in the Sundarbans?
Sea level rise is due to eustatic change from increased ocean water volume and greenhouse gas emissions causing thermal expansion.
What impact does the loss of mangrove forests have?
Loss of mangrove forests reduces natural protection against cyclones and tsunamis, putting coastal communities at risk.
What is the current density of mangrove trees in the Sundarbans?
The current density is 30 trees per 0.01 hectare, which helps reduce the force of a tsunami by 90%.
