Sundarbans


This article is about the Bangladeshi part. For the Indian part, see Sundarbans National Park.
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Sundarbans

 
 
 
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Sundarbans
Sun in Sunderbans.jpg
Sun in the Sundarbans
The Sundarbans
The Sundarbans
Location in Bangladesh
LocationKhulna Division, Bangladesh
Nearest cityKhulnaSatkhiraBagerhat
Coordinates21°57′N 89°11′ECoordinates21°57′N 89°11′E
Governing bodyGovernment of Bangladesh
 
Official nameThe Sundarbans
LocationKhulna Division, Bangladesh
Includes
CriteriaNatural: (ix)(x)
Reference798
Inscription1987 (11th Session)
Area139,500 ha (539 sq mi)
Coordinates21°57′N 89°11′E
 
Official nameSundarbans Reserved Forest
Designated21 May 1992
Reference no.560 [1]
Official nameSundarban Wetland
Designated30 January 2019
Reference no.2370 [2]

 

 

 

 

The Sundarbans (Bengaliসুন্দরবনromanizedShundorbônlit. 'Beautiful forest', Bengali pronunciation: [ˈʃundorbɔn]) is a mangrove area in the delta formed by the confluence of GangesBrahmaputra and Meghna Rivers in the Bay of Bengal. It spans from the Hooghly River in India's state of West Bengal to the Baleswar River in Bangladesh. It comprises closed and open mangrove forests, agriculturally used land, mudflats and barren land, and is intersected by multiple tidal streams and channels. Four protected areas in the Sundarbans are enlisted as UNESCO World Heritage Sites, viz Sundarbans National ParkSundarbans WestSundarbans South and Sundarbans East Wildlife Sanctuaries

The Sundarbans mangrove forest covers an area of about 10,000 km2 (3,900 sq mi), of which forests in Bangladesh's Khulna Division extend over 6,017 km2 (2,323 sq mi) and in West Bengal, they extend over 4,260 km2 (1,640 sq mi) across the South 24 Parganas and North 24 Parganas districts.[6] The most abundant tree species are sundri (Heritiera fomes) and gewa (Excoecaria agallocha). The forests provide habitat to 453 faunal wildlife, including 290 bird, 120 fish, 42 mammal, 35 reptile and eight amphibian species.

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 in the 20th century, and that the ecological quality of the forest is declining.[8] The Directorate of Forest is responsible for the administration and management of Sundarban National Park in West Bengal. In Bangladesh, a Forest Circle was created in 1993 to preserve the forest, and Chief Conservators of Forests have been posted since. Despite preservation commitments from both Governments, the Sunderbans are under threat from both natural and human-made causes. In 2007, the landfall of Cyclone Sidr damaged around 40% of the Sundarbans. The forest is also suffering from increased salinity due to rising sea levels and reduced freshwater supply. Again in May 2009 Cyclone Aila devastated Sundarban with massive casualties. At least 100,000 people were affected by this cyclone.[9][10] The proposed coal-fired Rampal power station situated 14 km (8.7 mi) north of the Sundarbans at Rampal Upazila of Bagerhat District in Khulna, Bangladesh, is anticipated to further damage this unique mangrove forest according to a 2016 report by UNESCO.

 

 

Etymology

The Bengali name Sundarban means "beautiful forest.   It may have been derived from the word Sundari, the local name of the mangrove species Heritiera fomes. Alternatively, it has been proposed that the name is a corruption of SamudrabanShomudrobôn ("Sea Forest"), or Chandra-bandhe (name of a primitive tribe). However, the generally accepted view is the one associated with Sundari or Sundri trees.

 

History

Village in a clearing of Sundarbans. Drawing by Frederic Peter Layard after an original sketch of 1839
Farm among paddy fields in the Sundarbans, 2010

The history of the area can be traced back to 200–300 AD. A ruin of a city built by Chand Sadagar 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 1769 following soon after proprietary rights were obtained from the Mughal Emperor Alamgir II by the British East India Company 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.[15]

The first Forest Management Division to have jurisdiction over the Sundarbans was established in 1869. In 1875 a large portion of the mangrove forests was declared as reserved forests under the Forest Act, 1865 (Act VIII of 1865). The remaining portions of the forests were declared a reserve forest the following year and the forest, which was so far administered by the civil administration district, was placed under the control of the Forest Department. A Forest Division, which is the basic forest management and administration unit, was created in 1879 with the headquarters in Khulna, Bangladesh. The first management plan was written for the period 1893–98.[16][17]

In 1911, it was described as a tract of waste country which had never been surveyed nor had the census been extended to it. It then stretched for about 266 kilometres (165 mi) from the mouth of the Hooghly River to the mouth of the Meghna river and was bordered inland by the three settled districts of the 24 Parganas, Khulna and Bakerganj. The total area (including water) was estimated at 16,900 square kilometres (6,526 sq mi). It was a water-logged jungle, in which tigers and other wild beasts abounded. Attempts at reclamation had not been very successful. The Sundarbans were intersected by river channels and creeks, some of which afforded water.

 

 

Geography


 
Geography view of sundarbans

The Sundarban forest lies in the vast delta on the Bay of Bengal formed by the super confluence of the GangesHooghlyPadmaBrahmaputra 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 km2 (3,900 sq mi) of which about 6,000 km2 (2,300 sq mi) are in Bangladesh. It became inscribed as a UNESCO world heritage site in [1987]. The Indian part of Sundarbans is estimated to be about 4,110 km2 (1,590 sq mi), of which about 1,700 km2 (660 sq mi) is occupied by waterbodies in the forms of river, canals and creeks of width varying from a few metres to several kilometres.

The Sundarbans is intersected by a complex network of tidal waterways, mudflats and small islands of salt-tolerant mangrove forests. The interconnected network of waterways makes almost every corner of the forest accessible by boat. The area is known for the Bengal tiger (Panthera tigris tigris), as well as numerous fauna including species of birds, spotted deercrocodiles and snakes. 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, taken together with the Sundarbans mangroves, are important habitat for the endangered tiger. Additionally, the Sundarbans serves a crucial function as a protective barrier for the millions of inhabitants in and around Khulna and Mongla against the floods that result from the cyclones. The Sundarbans has also been enlisted among the finalists in the New7Wonders of Nature.

 

 

Physiography

SPOT satellite image of Sundarbans, released by CNES
 
 
Landsat 7 image of Sundarbans, released by NASA Earth Observatory

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. Larger part is situated in Bangladesh, a smaller portion of it lies in India. The Indian part of the forest is estimated to be about 40 percent, while the Bangladeshi part is 60 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.[18]

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.[19]

Biotic factors here play a significant role in physical coastal evolution, and for wildlife a variety of habitats have developed which include beaches, estuaries, permanent and semi-permanent swamps, tidal flats, tidal creeks, coastal dunes, back dunes and levees. The mangrove vegetation itself assists in the formation of new landmass and the intertidal vegetation plays a significant role in swamp morphology. The activities of mangrove fauna in the intertidal mudflats develop micromorphological features that trap and hold sediments to create a substratum for mangrove seeds. The morphology and evolution of the eolian dunes is controlled by an abundance of xerophytic and halophytic plants. Creepers, grasses and sedges stabilise sand dunes and uncompacted sediments. The Sunderbans mudflats (Banerjee, 1998) are found at the estuary and on the deltaic islands where low velocity of river and tidal current occurs. The flats are exposed in low tides and submerged in high tides, thus being changed morphologically even in one tidal cycle. The tides are so large that approximately one third of the land disappears and reappears every day  The interior parts of the mudflats serve as a perfect home for mangroves.

 

 

 

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 14,600 square kilometres (5,600 sq mi) of the vast Ganges-Brahmaputra Delta, extending from the northern part of Khulna District and finishing at the mouth of the Bay of Bengal with scattered portions extending into India's West Bengal state. The Sundarbans freshwater swamp forests lie between the upland Lower Gangetic plains moist deciduous forests and the brackish-water Sundarbans mangroves bordering the Bay of Bengal.[22]

A victim of large-scale clearing and settlement to support one of the densest human populations in Asia, this ecoregion is under a great threat of extinction. Hundreds of years of habitation and exploitation have exacted a heavy toll on this ecoregion's habitat and biodiversity. There are two protected areas – Narendrapur (110 km2) and Ata Danga Baor (20 km2) that cover a mere 130 km2 of the ecoregion. Habitat loss in this ecoregion is so extensive, and the remaining habitat is so fragmented, that it is difficult to ascertain the composition of the original vegetation of this ecoregion. According to Champion and Seth (1968), the freshwater swamp forests are characterised by Heritiera minorXylocarpus molluccensisBruguiera conjugataSonneratia apetalaAvicennia officinalis, and Sonneratia caseolaris, with Pandanus tectoriusHibiscus tiliaceus, and Nipa fruticans along the fringing banks.

 

 

Natural hazards

According to a report created by UNESCO, the landfall of Cyclone Sidr damaged around 40% of Sundarbans in 2007

 

 

 

 

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 (8.7 mi) 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.[55][56] The government of Bangladesh rejected the allegations that the coal-based power plant would adversely affect the world's largest mangrove forest.[57]

On 9 December 2014 an oil-tanker named Southern Star VII, carrying 358,000 litres (79,000 imp gal; 95,000 US gal) of furnace oil,[59][60] was sunk in the Sela river ] of Sundarbans after it had been hit by a cargo vessel.  The oil spread over 350 km2 (140 sq mi) area after the clash, as of 17 December. The slick spread to a second river and a network of canals in the Sundarbans and blackened the shoreline.  The event was very threatening to trees, plankton, vast populations of small fishes and dolphins.  The event occurred at a protected Sundarbans mangrove area, home to rare Irrawaddy and Ganges dolphins. Until 15 December 2014 only 50,000 litres (11,000 imp gal; 13,000 US gal) of oil from the area were cleaned up by local residents, Bangladesh Navy and the government of Bangladesh.[59][66] Some reports indicated that the event killed some wildlife.[61] On 13 December 2014, a dead Irrawaddy dolphin was seen floating on the Harintana-Tembulbunia channel of the Sela River.