33 terms

Case study of a contrasting coastal landscape - Sundarbans

Coastal zone occupying the world's largest delta
Extent of coastline over of Southern Bangladesh and India on the bay of Bengal
Delta formed from sediments deposited by
the Ganges, Brahmaputra and Meghna
Natural climax ecosystems of the Sundarbans
Mangrove forests and swamps
Tidal action
Primary natural process that shapes distinctive coastal landscape
Dense well-developed network of interconnecting river channels
Flows across the clay and silt deposits
Traditionally location of the network of main channels remained relatively static
Due to silts and clays being quite resistant to erosion
Larger channels are generally straight and up to 2 or more km wide
Flowing generally north to south due to strong tidal currents
Extensive network of interconnecting smaller channels (khals)
Drains the land with each powerful ebb tide
Non-cohesive sediments like sand
Washed out of the delta and deposited on banks or chars at the river mouths, where the strong south-westerly monsoon winds then blow them into large ranges of sand dunes
With the protection of the dunes finer silts washed into the bay are deposited
Where wave action then adds and shapes further deposits of sand to form new islands
Vegetation establishes itself and eventually if the natural succession can proceed
Dense mangrove forests can develop
Unique coastal landscape where for millennia rivers have brought in rich sediment that
Has created the diverse mangrove forests that have sustained local populations for generations
Coastal flooding
Can lead to salinisation of soil and make it hard to grow crops
Low-lying land
At risk from rising sea levels due to global warming
Access is difficult
Due to few, poor quality roads which limits opportunities for development and makes it harder to receive goods, healthcare and education
Home to dangerous animals that attack humans
Such as tigers, sharks and crocodiles
Over-exploitations of coastal resources
From vulnerable habitats
Conversion of wetlands
To intensive agriculture and settlements
Use of fishing techniques
That are destructive to the environment
Lack of awareness of the environmental and economic importance of the region
As growing population has led to a need for more fuel and agricultural land, so the mangrove forests are removed which increases the risk of flooding and coastal erosion
Resource use conflicts
lack of fresh water for drinking and irrigation in the area, due to fresh water being diverted from the rivers for irrigation or agricultural land further upstream
Decision makers
may have a lack of awareness of coastal issues
There is a lack of employment
and income opportunities
Wealth of good and services
Has allowed local populations to remain resilient to the challenges of this low lying coastal landscape
Mangrove forests provide a high level of resilience as they provide significant protection and shelter against
Storm winds, floods, tsunamis, coastal erosion
A density of 30 trees per 0.01 hectares
can reduce the destructive force of a tsunami by up to 90%
Coastal communities of the Sundarbans
said to be more resilient than other coastal communities elsewhere in Bangladesh
Fertility of the soil and ecological diversity
provides a plentiful supply of a large range of nutritious food
The forests have an economic value
even if used for fishing, gathering crustaceans, or timber and tannin production
Just one hectare of mangrove forest is estimated to have an annual economic value of
over $12,000
The mangroves could provide
resilience against poverty and opportunities for sustainable economic development in the future for people living there
The Sundarbans could utilise a number of open access natural resources including
khas land, wetlands and fisheries, forests