Ganges Delta

Coordinates: 22°42′N 89°40′E / 22.700°N 89.667°E / 22.700; 89.667
Source: Wikipedia, the free encyclopedia.
(Redirected from
Ganges–Brahmaputra Delta
)

Ganges Delta, 2020 satellite photograph.

The Ganges Delta (also known the Ganges-Brahmaputra Delta, the Sundarbans Delta or the Bengal Delta

Ganges river. It is also one of the most fertile regions in the world, thus earning the nickname the Green Delta. The delta stretches from the Hooghly River east as far as the Meghna River
.

Geography

A typical landscape in the Delta with palms, rice, flat, green and ponds
Delta of Ganges from the map of surveyor James Rennell (1778)

The Ganges Delta has the shape of a triangle and is considered to be an "arcuate" (arc-shaped) delta. It covers more than 105,000 km2 (41,000 sq mi) and lies mostly in Bangladesh and India, with rivers from

fluvio-glacial. Red and red-yellow laterite
soils are found as one heads farther east. The soil has large amounts of minerals and nutrients, which is good for agriculture.

It is composed of a labyrinth of channels, swamps, lakes, and flood plain sediments (chars). The Gorai-Madhumati River, one of the distributaries of the Ganges, divides the Ganges Delta into two parts: the geologically young, active, eastern delta, and the older, less active, western delta.[1]

Population

Around 280 million (180 million Bangladesh & 100 million West Bengal, India) people live on the delta,[citation needed] despite risks from floods caused by monsoons, heavy run-off from the melting snows of the Himalayas, and North Indian Ocean tropical cyclones. A large part of the nation of Bangladesh lies in the Ganges Delta; many of the country's people depend on the delta for survival.[4]

It is believed that upwards of 300 million people are supported by the Ganges Delta; approximately 400 million people live in the Ganges River Basin, making it the most populous river basin in the world. Most of the Ganges Delta has a population density greater than 200/km2 (520 people per square mile),[citation needed] making it one of the most densely populated regions in the world.

Wildlife

Bengal tiger

Three

Sundarbans mangroves form the world's largest mangrove ecoregion, covering an area of 20,400 square kilometres (7,900 sq mi) in a chain of 54 islands. They derive their name from the predominant mangrove species, Heritiera
fomes, which are known locally as sundri or sundari.

Animals in the delta include the Indian python (

peepal
trees are found in these areas.

It is estimated that 30,000

endangered
.

Trees found in the delta include sundari, garjan (Rhizophora spp.), bamboo, mangrove palm (Nypa fruticans), and mangrove date palm (Phoenix paludosa).

Geology

The Ganges Delta lies at the junction of three tectonic plates: the Indian Plate, the Eurasian Plate, and the Burma Plate.[5] The edge of the Eocene paleoshelf runs approximately from Kolkata to the edge of the Shillong Plateau. The edge of the paleoshelf marks the transition from the thick continental crust in the northwest to the thin continental or oceanic crust in the southeast. The enormous sediment supply from the Himalayan collision has extended the delta about 400 kilometres (250 mi) seaward since the Eocene. The sediment thickness southeast of the edge of the paleoshelf beneath the Ganges Delta can exceed 16 km (9.9 mi).[6]

Economy

Rice, cattle and fishing in rivers and ponds are important sources of food.

Approximately two-thirds of the Bangladesh people work in agriculture and grow crops on the fertile floodplains of the delta. The major crops that are grown in the Ganges Delta are jute, tea, and rice.[4] Fishing is also an important activity in the delta region, with fish being a major source of food for many of the people in the area.[7]

In the last decades of the 20th century, scientists helped the poor people of the delta to improve fish farming methods. By turning unused ponds into viable fish farms and improving methods of raising fish in existing ponds, many people can now earn a living raising and selling fish. Using new systems, fish production in existing ponds has increased 800%.[8] Shrimp are farmed in containers or cages that are submerged in open water. Most are exported.[7]

A lot of bustle at a ferry pier
The Vidyasagar Setu which spans the Hoogli River in Kolkata

As there is a maze of many river branches, the area is difficult to pass. Most islands are only connected with the mainland by simple wooden ferryboats. Bridges are rare. Some islands are not yet connected to the electric grid, so island residents tend to use solar cells for a bit of electric supply.

Arsenic pollution

Arsenic is a naturally occurring substance in the Ganga Delta that has detrimental effects on health and may enter the food chain, especially in key crops such as rice.

Climate

The Ganges Delta lies mostly in the tropical wet climate zone, and receives between 1,500 to 2,000 mm (59 to 79 in) of rainfall each year in the western part, and 2,000 to 3,000 mm (79 to 118 in) in the eastern part.[citation needed]. Hot, dry summers and cool, dry winters make the climate suitable for agriculture.

Cyclones and flooding

In November 1970, the deadliest tropical cyclone of the twentieth century hit the Ganges Delta region. The

The Guinness Book of World Records estimated the total loss of human life from the Bhola cyclone at 1,000,000.[9]

Another cyclone hit the delta in 1991, killing about 139,000 people.[10]
It also left many people homeless.

People have to be careful on the river delta as severe flooding also occurs. In 1998, the Ganges flooded the delta, killing about 1,000 people and leaving more than 30 million people homeless. The Bangladesh government asked for $900 million to help feed the people of the region, as the entire rice crop was lost.[11]

History of the Bengal Delta

The history of the Bengal delta has been a concern of emerging scholarship by environmental historians.

Indian historian Vinita Damodaran has extensively profiled famine management practices by the East India Company, and related these practices to major ecological changes wrought about by forest and land management practices.[12][13][14] Debjani Bhattacharyya has shown how Calcutta was constructed as an urban centre through tracing ecological changes wrought upon by colonial powers involving land, water and humans throughout the mid-18th to the early 20th centuries.[15][16]

In terms of recent scholarship that focuses more on the eastern part of the Bengal/Ganges Delta, Iftekhar Iqbal argues for the inclusion of the Bengal Delta as an ecological framework within which to study the dynamics of agrarian prosperity or decline, communal conflicts, poverty and famine, especially throughout the colonial period.[17] Iqbal has tried to show how resistance movements such as the Faraizi movement can be studied in relation to colonial ecological management practices.[18]

A strong criticism of environmental history scholarship with regards to the Bengal/Ganges delta is that most of the scholarship is limited to the 18th to the 21st centuries, with a general dearth of ecological history of the region prior to the 18th century.

Future of the delta

One of the greatest challenges people living on the Ganges Delta may face in coming years is the threat of

rising sea levels caused by climate change. An increase in sea level of 0.5 metres (1 ft 8 in) could result in six million people losing their homes in Bangladesh.[19]

Important gas reserves have been discovered in the delta, such as in the Titas and Bakhrabad gas fields. Several major oil companies have invested in exploration of the Ganges Delta region.[20][21]

Tidal river management

To offset

tidal river management has been implemented in the delta.[22][23][24] This method has been implemented in 5 beels and resulted in benefits including decreased waterlogging, creation of agricultural areas, improved navigation and land creation.[22][25]

View

Ganga/Padma River from Space

See also

Notes

  1. ^ a b Chowdhury, Sifatul Quader; Hassan, M Qumrul (2012). "Bengal Delta". In Islam, Sirajul; Jamal, Ahmed A. (eds.). Banglapedia: National Encyclopedia of Bangladesh (Second ed.). Asiatic Society of Bangladesh.
  2. ^ Seth Mydans (21 June 1987). "Life in Bangladesh Delta: On the Edge of Disaster". The New York Times. Archived from the original on 4 November 2017.
  3. ^ "Where Is The Largest Delta In The World?". WorldAtlas. 25 April 2017.
  4. ^ a b Bowden 2003, p. 39: "Many of [Bangladesh's] people depend on the delta for their survival. Two-thirds of Bangladeshis work in agriculture and grow crops on the fertile delta floodplains. Jute fiber, used to make twine and sacking, is Bangladesh's main export crop. Tea, wheat, rice, beans, sugarcane, and fruits are grown."
  5. ^ "Tectonics & Geophysics". BanglaPIRE. Archived from the original on 17 June 2017. Retrieved 13 June 2017. The Ganges Brahmaputra Delta lies at the junction of three plates: the Indian Plate, the Eurasian Plate and the Burma Platelet.
  6. . Retrieved 22 April 2013. The edge of the pre-delta Eocene paleoshelf is marked by the shallow-water Sylhet Limestone, which runs NNE from near Calcutta to the edge of the Shillong Plateau ... The Sylhet Limestone drops ... indicating the presence of thick continental crust. East of the hinge zone the great thickness of sediments indicates that the crust is greatly thinned or oceanic ... The enormous supply of sediments provided by the Himalayan collision fed the [Ganges-Brahmaputra Delta (GBD)] and has produced ~400 km of progradation of the shelf edge since the Eocene ... Total sediment thickness beneath the GBD southeast of the hinge zone exceeds 16 km.
  7. ^ a b Bowden 2003, p. 44: "Fishing has played a part in the lives of Bangladeshi people for a long time ... Fish is particularly important in Bangladesh, where it provides the main source of protein in the diet of many people ... Shrimp are farmed in large containers or cages that are submerged in the open water. They are mainly sold for export."
  8. ^ "Global Demand for Fish Rising—Fish Farming is the Fastest Growing Field of Agriculture". Future Harvest. Archived from the original on 5 October 2006. In Bangladesh, scientists are turning unused ponds into viable fish farms and improving fish raising in the existing ones. The project has led to a new way for the rural poor to earn an income ... Using new systems developed through research, fish production in existing ponds has increased eightfold.
  9. ^ "History and Society/Disasters/Cyclone Deaths". Guinness World Records. Archived from the original on 19 November 2005. Retrieved 12 July 2013.
  10. ^ Bowden 2003, p. 43: "In 1970 Bangladesh suffered the world's worst recorded cyclone, when about 500,000 people were killed. The last bad cyclone to strike Bangladesh was in 1991. It killed 139,000 people."
  11. ^ Bowden 2003, p. 40: "In 1998 ... About one thousand people were killed, and more than 30 million were left homeless by floods ... The entire rice crop was ruined, and the government asked for almost $900 million dollars of aid to help it feed and rehouse its people."
  12. .
  13. .
  14. . Retrieved 25 January 2020.
  15. .
  16. .
  17. .
  18. ^ Bowden 2003, p. 44-45: "The greatest change Bangladesh and its people may face in the coming years will probably be the threat of global warming ... One of the likely results of global warming is a gradual rise in sea levels. This could be 1.6 feet (0.49 meters) by 2100. That might not sound like very much, but it would mean that 6 million Bangladeshis would lose their homes."
  19. .
  20. ^ Bowden 2003, p. 41: "Gas reserves ... lie under the delta region and offshore in the Bay of Bengal. Important discoveries were made during the 1990s, and several major oil companies have invested in gas exploration in Bangladesh."
  21. ^
    ISSN 1462-9011
    .
  22. .
  23. .
  24. .

References

External links

22°42′N 89°40′E / 22.700°N 89.667°E / 22.700; 89.667