Coasts: Sundarbans

Question 1

Location

Answer 1

Southern Bangladesh and India are on the Bay of Bengal. The Sundarbans is situated on the delta created by the confluence of the Ganges, Brahmaputra and Meghna rivers in the Bay of Bengal. The delta is a network of mudflats and islands created by accumulated sediment that these rivers carry from the Himalayan headwaters separated by tidal waterways. The Sundarbans is the world’s largest mangrove forest.

Question 2

Facts

Answer 2

• largest mangrove in the world 100,00km2
• 2m fish a year in the mangrove for fishmongers
• 400 000 fisherman earn livelihoods
• mangroves support 2.3 million people

Question 3

Coastal process

Answer 3

Tidal action-
Shapes the distinctive landscape. Dense network of river channels flow across the clay and sit fluvial deposits. The channels flow north to south due to strong tidal currents, and smaller channels drain the land with each tide.

Deposition-
Sediment is washed out of the delta and deposited on bank or at river mouths, where strong south west wind blows them into sand dunes. Mangrove forests develop.

Question 4

Opportunities

Answer 4

Agriculture:
- aquaculture and fisheries provide most important income for local people (53%)
- employment for 1.2m and seasonal jobs for 10m people.
- HOWEVER, unsustainable, pollution and could introduce invasive species.

Construction:
- timber is used from mangrove trees for construction
- palms used for thatching construction of small huts, cheap fencing
- creates jobs
- HOWEVER, Can cause long term damage and corrupt forest officers give permits to locals to cut down, pay bribes.

Ecotourism:
- mangrove have unique biodiversity
- rare bengal tigers and crocodiles
- 3 wildlife sanctuaries
- wife range of flora and fauna: 334 plant species
- tourism raises awareness

Protection from natural hazards:
- protection from tropical storms. Floods and storm surges
- height of waves passing through mangroves is reduced due to roots and branches, reduce wave energy to cause damage
- dense mangroves are highly effective debris trap, protecting people and infrastructure

Question 5

Risks

Answer 5

• access is difficult limiting opportunity for everyone
• lack of fresh water for drinking because fresh water is diverted from rivers to irrigation systems for agriculture
• mangrove forests are being removed due to increase demand for fuel and food which increases flood risk
• flooding can lead to salinisation making it har to grow cops
• home to dangerous animals which attack humans
• poor regions: people don’t get warnings about floods

Question 6

Over coming risks: resilience

Answer 6

• Public health engineering department increased access to fresh water and sanitation
• Better bridges and roads are being built (HOWEVER, this can lead to deforestation)
• Electricity being extended to more areas - easier communication about flood warnings
• Increased food security by providing farming subsidies. HOWEVER, some areas may be
  farmed too intensively (environmental damage)
• Some NGOs are providing training in farming and fishing to help reduce overexploitation.

Question 7

Overcoming risks: mitigation

Answer 7

• 3500km embankments built to reduce flooding. HOWEVER, the embankments are being
  eroded. 800m are at risk of being breached by tsunamis
• Aim to protect existing mangrove forests and replant areas that have been removed to
  protect against flooding and erosion. HOWEVER, it is difficult to prevent illegal forest
  clearing throughout the whole region and it is unclear whether the mangroves will
  withstand sea level rise.
• Attempts to mitigate the impacts of extreme events e.g. cyclones. For example, the
  government and NGOs have provided funding for cyclone shelters and early warning
  systems, which should help people shelter and evacuate. HOWEVER, many people may
  not have transport available to enable them to evacuate quickly.

Question 8

Overcoming risks: adaptation

Answer 8

• Salt resistant rice is being grown to help residents cope with flooding and sea level rise.
  HOWEVER, relying on a smaller variety of crops decreases biodiversity and increases
  the risk of disease for plants.
• Projects to increase tourism providing jobs e.g. lodges and boat trips. HOWEVER Tourism can cause environmental issues e.g pollution
• Houses are being built on stilts to protect them from sea level rise. HoWEVER, infrastructure
  such as roads cannot be protected easily.
• Sustainable adaptations e.g. using non-intensive farming practices and promoting ecotourism, will help ensure that the fragile environment remains relatively undamaged and usable for future generations