Sundarbans :
The Sundarbans
Shundorbôn) is a natural region
comprising southern Bangladesh and a small part in Eastern India. It is the
largest single block of tidal halophytic mangrove forest in the world. The Sundarbans
covers approximately 10,000 square kilometres (3,900 sq mi) most of
which is in Bangladesh with the remainder in India .The
Sundarbans is a UNESCO World Heritage Site .
Sundarbans South , East and
West are three protected forests in Bangladesh. This region is densely covered
by mangrove forests, and is the largest reserves for the Bengal tiger. The
Sundarbans National Park is a National Park, Tiger Reserve, and a Biosphere
Reserve located in the Sundarbans delta in the Indian state of West Bengal.
History
House in Sundarbans with a pond and rice fields, 2010
The history of the area can be traced back to 200–300 AD.
A ruin of a city built by Chan Sadaga has been found in the
Baghmara Forest Block. During the Mughal period, the Mughal
Kings leased the forests of the Sundarbans to nearby residents. Many criminals
took refuge in the Sundarbans from the advancing armies of Emperor Akbar. Many
have been known to be attacked by tigers. Many
of the buildings which were built by them later fell to hands of Portuguese
pirates, salt smugglers and dacoits in the 17th century. Evidence of the fact
can be traced from the ruins at Netidhopani and other places scattered all over
Sundarbans. The legal status of the
forests underwent a series of changes, including the distinction of being the
first mangrove forest in the world to be brought under scientific management.
The area was mapped first in Persian, by the Surveyor General as early as 1764
following soon after proprietary rights were obtained from the Mughal Emperor
Alamgir II by the British in 1757.
Systematic management of this forest tract started in the 1860s after the
establishment of a Forest Department in the Province of Bengal, in British
India. The management was entirely designed to extract whatever treasures were
available, but labour and lower management mostly were staffed by locals, as
the British had no expertise or adaptation experience in mangrove forests.
Geography
Map of Sundarbans
The Sundarban forest lies in the vast delta on the Bay of Bengal
formed by the super confluence of the Ganges, Padma, Brahmaputra and
Meghna
rivers across southern Bangladesh.
The seasonally flooded Sundarbans freshwater swamp forests lie
inland from the mangrove forests on the coastal fringe. The forest covers
10,000 square kilometres (3,900 sq mi) of which about 6,000 square
kilometres (2,300 sq mi) are in Bangladesh.[12] It
became inscribed as a UNESCO world heritage
site in 1997. The Indian part of Sundarbans is estimated to be about 4,110
square kilometres (1,590 sq mi), of which about 1,700 square
kilometres (660 sq mi) is occupied by waterbodies in the forms of
river, canals and creeks of width varying from a few meters to several
kilometres.
Physiography
The mangrove-dominated Ganges Delta –
the Sundarbans – is a complex ecosystem
comprising one of the three largest single tracts of mangrove forests of
the world. Situated mostly in Bangladesh, a
small portion of it lies in India. The Indian part of the forest is estimated
to be about 19 percent, while the Bangladeshi part is 81 percent. To
the south the forest meets the Bay
of Bengal; to the east it is bordered by the Baleswar River and
to the north there is a sharp interface with intensively cultivated land. The
natural drainage in the upstream areas, other than the main river channels, is
everywhere impeded by extensive embankments and polders.
The Sundarbans was originally measured (about 200 years ago) to be of about
16,700 square kilometres (6,400 sq mi). Now it has dwindled into
about 1/3 of the original size. The total land area today is 4,143 square
kilometres (1,600 sq mi), including exposed sandbars
with a total area of 42 square kilometres (16 sq mi); the remaining
water area of 1,874 square kilometres (724 sq mi) encompasses rivers,
small streams and canals. Rivers in the Sundarbans are meeting places of salt
water and freshwater. Thus, it is a region of transition between the freshwater
of the rivers originating from the Ganges and the saline water of the Bay of
Bengal.
The Sundarbans along the Bay of Bengal has evolved over
the millennia through natural deposition of upstream sediments accompanied by
intertidal segregation. The physiography is dominated by deltaic formations
that include innumerable drainage lines associated with surface and subaqueous
levees, splays and tidal flats. There are also marginal marshes above mean tide
level, tidal sandbars and islands with their networks of tidal channels,
subaqueous distal bars and proto-delta clays and silt sediments. The
Sundarbans' floor varies from 0.9 to 2.11 metres (3.0 to 6.9 ft) above sea
level.
Sundarbans freshwater swamp forests
The Sundarbans freshwater swamp forests are a tropical moist broadleaf forest ecoregion of Bangladesh. It
represents the brackish swamp forests that lie behind the Sundarbans
Mangroves, where the salinity is more pronounced. The freshwater ecoregion
is an area where the water is only slightly brackish and becomes quite fresh
during the rainy season, when the freshwater plumes from the Ganges and the
Brahmaputra rivers push the intruding salt water out and bring a deposit of
silt. It covers an area of 14,600 square kilometres (5,600 sq mi) of
the .
Sundarbans Mangroves
See also: Mangrove
The Sundarbans Mangroves ecoregion on the coast forms the
seaward fringe of the delta and
is the world's largest mangrove
ecosystem, with 20,400 square kilometres (7,900 sq mi) of area
covered. The dominant mangrove species Heritiera
fomes is locally known as sundri or sundari.
Mangrove forests are not home to a great variety of plants.
Twenty-six of the fifty broad mangrove types found in the
world grow well in the Sundarbans. The commonly identifiable vegetation that
grow in the dense mangrove forests at the Sundarbans are salt water mixed
forest, mangrove scrub, brackish water mixed forest, littoral forest, wet
forest and wet alluvial grass forests. The Bangladesh mangrove vegetation of
the Sundarbans differs greatly from other non-deltaic coastal mangrove forests
and upland forests associations. Unlike the former, the Rhizophoraceae are
of minor importance.
Flora
The Sundarbans flora is characterised by the abundance of
sundari ,
It yields a hard
wood, used for building houses and making boats, furniture and other
things.
New forest accretions is often conspicuously dominated by keora and
tidal forests. It is an indicator species for newly accreted
mudbanks and is an important species for wildlife, especially spotted
deer .
There is abundance of dhundul or passur and kankra
though distribution is discontinuous. Among palms, Poresia coaractata, Myriostachya
wightiana and golpata , and among grasses spear grass
and khagra are well distributed.
whole mosaic of seres,
comprising primary colonisation on new accretions to more mature beach
forests. Historically vegetation types have been recognised in broad
correlation with varying degrees of water salinity, freshwater flushing and
physiography.
Fauna
The Sundarbans provides a unique ecosystem and a rich
wildlife habitat. According to the 2015 tiger census, the Sundarbans have about
170 tigers (106 in Bangladesh and 64 in India).
Although previous rough estimates had suggested much higher figures close to
300, the 2011 census provided the first ever scientific estimate of tigers from
the area
Tiger attacks are frequent in the Sundarbans. Between 0 and 50 people are
killed each year.
Predators
The fertile soils of the delta have been subject to
intensive human use for centuries, and the ecoregion has been mostly converted
to intensive agriculture, with few enclaves of forest remaining. The remaining
forests, together with the Sundarbans mangroves, are important habitats for the
endangered Bengal tiger (Panthera tigris). The forest also contains leopard (Panthera pardus fusca)
and several other smaller predators such as the jungle cats (Felis chaus), fishing cats (Prionailurus viverrinus),
and leopard cats (Prionailurus bengalensis).
.
Endangered and extinct species
Gangetic
dolphin, drawing from 1894
Forest inventories reveal a decline in standing volume of
the two main commercial mangrove species – sundari (Heritiera spp.) and gewa (Excoecaria
agallocha) — by 40% and 45% respectively between 1959 and 1983.
Despite a total ban on all killing or capture of wildlife
other than fish and some invertebrates, it
appears that there is a consistent pattern of depleted biodiversity or loss of
species (notably at least six mammals and one important reptile) in the 20th
century, and that the "ecological quality of the original mangrove forest
is declining".
Climate change impact
Mudflats in
Sundarbans
The physical development processes along the coast are
influenced by a multitude of factors, comprising wave motions, micro and
macro-tidal cycles and long shore currents typical to the coastal tract. The
shore currents vary greatly along with the monsoon.
These are also affected by cyclonic
action. Erosion and accretion through these forces maintains varying levels, as
yet not properly measured, of physiographic change whilst the mangrove
vegetation itself provides a remarkable stability to the entire system. During
each monsoon season almost all the Bengal Delta is submerged, much of it for
half a year. The sediment of the lower delta plain is primarily advected inland
by monsoonal coastal setup and cyclonic events. One of the greatest challenges
people living on the Ganges Delta may
face in coming years is the threat of rising sea levels caused mostly by subsidence in
the region and partly by climate change.
the part of the India and Bangladesh governments coupled
with natural ecological changes were forcing the flight of human capital from
the region .
Man made hazards
In August 2010, a Memorandum of Understanding was
signed between Bangladesh Power Development Board
(BPDB) and India's state-owned National Thermal Power Corporation
(NTPC) where they designated to implement the coal-fired Rampal power station
by 2016.The proposed project, on an area of over 1,834 acres of land, is
situated 14 kilometres north of the Sundarbans. This project violates the environmental impact assessment
guidelines for coal-based thermal power plants. Environmental activists contend
that the proposed location of the Rampal Station would violate provisions of
the Ramsar Convention.The
government of Bangladesh rejected the allegations that the coal-based power
plant would adversely affect the world's largest mangrove forest.
Economy
Ferry boat in the Sundarbans
The Sundarbans plays an important role in the economy of
the southwestern region of Bangladesh as
well as in the national economy. It is the single largest source of forest produce in
the country. The forest provides raw materials for wood based industries. In
addition to traditional forest produce like timber, fuelwood, pulpwood etc.,
large scale harvest of non-wood forest products such as thatching materials, honey, bees-wax, fish, crustacean
and mollusc resources of the forest takes place regularly. The vegetated tidal
lands of the Sundarbans also function as an essential habitat, produces
nutrients and purifies water. The forest also traps nutrient and sediment, acts
as a storm barrier, shore stabiliser and energy storage unit. Last but not the
least, the Sunderbans provides a wonderful aesthetic attraction for local and
foreign tourists.
Administration
The Sundarbans area is one of the most densely populated
in the world, and the population is increasing. As a result, half of this
ecoregion's mangrove forests have been cut down to supply