Coasts: Sundarbans, Bangladesh (LIC) Flashcards
Where are the sundarbans located, what does it consist of?
The Sundarbans is a coastal zone occupying the world’s largest delta, that extends over 10,000km squared of Southern Bangladesh and India on the Bay of Bengal. Consists of mangrove forests and swamps in the delta, deposited by three contributing rivers (Ganges, Brahmaputra and Meghna.)
List 5 natural challanges of the area
-Coastal flooding and storm surges (cyclones.)
-High salinity in soil
-Instability of islands
-Accessibility and remoteness
-Man-eating tigers
List 5 human challanges of the area
-Over-exploiting coastal resources
-Destructive fishing techniques
-Lack of awareness of the importance of the region by both dwellers and decision-makers
-4 million population, combined with a battle for resources leads to deforestation, increasing flood risk
-Poverty: only 20% have electricity, and lack of communicating leads to increased dangers during floods.
What mitigation strategies have been used to reduce the severity of flood events and cyclones
-3500km embankments (however 800km may be breached/destroyed during flooding)
-Coastal management: replant mangrove trees (may not survive sea level rise)
-Cyclone shelters built with communication and supplies (government built 100 shelters in coastal bangladesh between 2011-15, 750 more proposed in 2019.)
Adaptation strategies
-Salt resistant rice crops (can last up to 2 weeks submerged)
-Tourism developent projects
-Houses on stilts
-Non-intensive farming straggles
What is a mangrove?
-Mangroves are salt-tolerant forests of trees and shrubs that grow in the tidal estuaries and coastal zones of tropical areas. The muddy waters, rich in nutrients from decaying leaves and wood, are home to a huge variety of biodiversity. The Sundarbans is the largest in the world (570,000 ha)
What are the uses of mangroves?
-Provide large quantities of food (such as crops and fish)
-Provide fuel
-Provide medicine
-Provide building materials
-Mangroves also protect coastlines by absorbing the force of hurricanes and storms
-Mangroves also act as natural filters, absorbing nutrients from farming and sewage disposal
What is the pressure on mangrove forests?
-Many mangrove areas have been lost to rice paddies and shrimp farms
-As population growth is set to increase in mangrove areas, the future of mangroves looks bleak
-Already most Caribbean and South Pacific Mangroves have disappeared and the risk is that the same will occur in Sundarbans
What are the ecological services that mangroves provide?
-Products such as fuel wood, charcoal, timber and food such as shellfish and crustaceans
-Many fish species both farmed commercially and for subsistence use mangrove swamps as nurseries.
Ecotourism
-The mangroves have unique biodiversity (rare bengal tigers and crocodiles)
-3 wildlife sanctuaries covering over 139,000 hectares
-Breeding ground for endangered species
-Wide range of fauna and flora: 334 plant species
-Mangrove mud provides a fish nursery for marine wildlife
-Sustainable
-Tourism raises awareness of the importance of mangroves, encouraging the conservation
How do the mangroves provide climate regulation?
-Important carbon sinks for atmospheric carbon
-Help combat global warming however, deforestation of the mangroves for timber reduces the carbon stored, releasing carbon into atmosphere
Risks in the Sundarbans
-Access is difficult, limiting opportunity for development
-Lack of freshwater for drinking because freshwater is diverted from rivers to irrigation systems for agriculture
-Mangrove forests are being removed due to increased demand for food and fuel which increases flood risk
-Flooding can lead to salinisation making it hard to grow crops
-Home to dangerous animals (man eating tigers) which attack humans
-poor region so residents do not get warnings about floods
Attempts to improve resilience:
-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 reduce overexploitation.
Mitigation in sundarbans
-3500km embankments built to reduce flooding. However, the embankments are being eroded and 800m at risk of being breached by tsunamis.
-Aim to protect existing mangrove forests and replant ares 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 eg. 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.
Adaptations in the Sundarbans
-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 eg. Lodges and boat trips. However, tourism can cause environmental issues such as 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 eg. Using non-intensive farming practices and promoting ecotourism will help ensure that fragile environment remains relatively undamaged and useable for future generations.
