The Sundarbans (Bengali: সুন্দরবন, Shundorbôn) is the largest single block of tidal halophytic mangrove forest in the world. The name Sundarban can be literally translated as "beautiful jungle" or "beautiful forest" in the Bengali language (Sundar, "beautiful" and ban, "forest" or "jungle"). The name may have been derived from the Sundari trees that are found in Sundarbans in large numbers. Alternatively, it has been proposed that the name is a corruption of Samudraban (Bengali: সমুদ্রবন Shomudrobôn "Sea Forest") or Chandra-bandhe (name of a primitive tribe). But the generally accepted view is the one associated with Sundari trees.The forest lies in the vast delta on the Bay of Bengal formed by the confluence of the Ganges, Brahmaputra and Meghna rivers across southern Bangladesh and West Bengal, India. The seasonally-flooded Sundarbans freshwater swamp forests lie inland from the mangrove forests on the coastal fringe. The forest covers 10,000 sq.km. of which about 6,000 are in Bangladesh. It became inscribed as a UNESCO world heritage site in 1997, but while the Bangladeshi and Indian portions constitute the same continuous ecotope, these are separately listed in the UNESCO world heritage list as the Sundarbans and Sundarbans National Park, respectively. The Sundarbans is intersected by a complex network of tidal waterways, mudflats and small islands of salt-tolerant mangrove forests. The area is known for the eponymous Royal Bengal Tiger (Panthera tigris tigris), as well as numerous fauna including species of birds, spotted deer, crocodiles 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, 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 Kolkata (Calcutta) against the floods that result from the cyclones that are a regular occurrence on this coast.
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, local kings leased the forests of the Sundarbans to residents. In this period, Raja Basanta Rai and his nephew took refuge in the Sundarbans from the advancing armies of Emperor Akbar.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 by the Surveyor General as early as 1764 following soon after proprietary rights were obtained from the Mughal Emperor Alamgir II by the 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 India.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 in 1875–76 under the Forest Act, 1865 (Act VIII of 1865). The remaining portions of forests was declared as reserve forest the following year and the forest, which was so far was 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 headquarter in Khulna. The first management plan was written for the period 1893–98.[6]
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 165 miles (266 km) from the mouth of the Hugli to the mouth of the Meghna and was bordered inland by the three settled districts of the 24 Parganas, Khulna and Backergunje. The total area (including water) was estimated at 6,526 square miles (16,902 km2). It was a water-logged jungle, in which tigers and other wild beasts abounded. Attempts at reclamation had not been very successful. The characteristic tree was the sundari (Heritiera littoralis), from which the name of the tract had probably been derived. It yields a hard wood, used for building, and for making boats, furniture, etc. The Sundarbans were everywhere intersected by river channels and creeks, some of which afforded water communication between Calcutta and the Brahmaputra Valley, both for steamers and for native boats.
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.
In many of the Indian mangrove wetlands, freshwater reaching the mangroves was considerably reduced from the late 19th century due to diversion of freshwater in the upstream area. Also, the Bengal Basin is slowly tilting towards the east due to neo-tectonic movement, forcing greater freshwater input to the Bangladesh Sundarbans. As a result, the salinity of the Bangladesh Sundarbans is much lower than that of the Indian Sundarbans. A 1990 study noted that there "is no evidence that environmental degradation in the Himalayas or a 'greenhouse' induced rise in sea level have aggravated floods in Bangladesh"; however, a 2007 report by UNESCO, "Case Studies on Climate Change and World Heritage" has stated that an anthropogenic 45-cm rise in sea level (likely by the end of the 21st century, according to the Intergovernmental Panel on Climate Change), combined with other forms of anthropogenic stress on the Sundarbans, could lead to the destruction of 75% of the Sundarbans mangroves. Already, Lohachara Island and New Moore Island/South Talpatti Island have disappeared under the sea, and Ghoramara Island is half submerged.
