Sundarbans Flashcards
Location
Bangladesh - South Asia
Bay of Bengal
Physical characteristics
Low-lying, flat
Sand banks, trees (stores)
Khals - small channels drain the land
Inputs - mountain sediment carried by river
Fractal/dentritic
Many rivers
Ecological importance
Amongst largest mangroves in the world
Globally 4.3% of mangroves in Sundarbans
Rich biodiversity
Large population of tigers
World heritage site
Biosphere reserve
The mangroves
Lost one third of all forests in last 15 years
Trees can survive high salinity
Tidal
75% of all tropical fish born here
Coral reefs depend on mangroves - filtering
Protection to wildlife in extreme weather
Formation of Sundarbans
Tidal action - high tide brings silt and clay deposits, low tie allows mangrove trees to grow
Three large rivers - Ganges, Brahmaputra, Meghna
Wave action - S.W. monsoon increases erosion which means increased sediment. Winds blow sediment to form sand banks and dunes where deposition can occur in middle of river channel. Vegetation begins to grow on islands and stabilise them
Opportunities
Hunting/gathering - fertile land, one ha of forest has annual value of $12,000
Forests - timber use for construction, firewood + furniture
Education - cyclone shelters have second purpose as schools - locals can understand importance of forest (80% don’t have secondary education)
Shrimp farming - large areas of forest destroyed for aquaculture, pollute and invasive species and cause erosion around estuaries, not helping locals (food/jobs) as dominated by wealthy companies
Threats to opportunities
Tigers threat to livestock
Lack of freshwater
Flooding + eustatic change lead to salination
Everything has to be made of wood - threatened by cyclones
Limited education - most only primary
Resilience of mangroves against cyclones, floods, tsunamis etc.
Leaves provide protection from storm wind
Roots - protection from floods and tsunami
Shallow water + roots stop coastal erosion further into forest
Challenges - social
Dangerous animals - tigers, crocs, sharks
Corrupt officials
Lack of electricity - 2/3 of households
Lack of accessibility
Increasing population
Challenges - economic
Lack of employment - locals need permits to harvest
Relatively poor region
Shrimp farming dominated by large companies
Challenges - environmental
Low-lying land at risk
Increased frequency and strength of cyclones
Rising sea level makes water too salty
Use of pesticide
Mitigation of threats - deforestation and tiger attacks
Deforestation - danger of completely vanishing. Indian NGO Nature Environment + Wildlife Society - reforesting mangroves that have depleted. 2015 - 50k planted
Tiger Attacks - avg. 23 people killed a year. Masks on back of head as tiger attacks from behind. Providing prey by releasing captive bred pigs
Electrified human dummies
Adaptation against cyclones and climate change
Cyclones - mangrove absorbs lots of the energy. 2015 - 1000 multi-purpose cyclone shelters built in vulnerable locations. Some have become neglected
Climate change + rising sea levels - USAID teaches resilience to future climate shocks - 30k people. Salt-tolerant rice varieties that can survive being submerged in sea water for over two weeks.
Bangladesh ICZM
Protect against natural hazards
Protection of natural environment
Improving rural livelihoods + economic prospects sustainably
Development of tourism and fishing sectors
Government agreements - India + Bangladesh
1972 - joint rivers commission to manage 54 common rivers
1997 - agreed to share waters of the Ganga
