Ganges

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Ganges
Ganga, Padma
The Ganges in Varanasi

The Ganges in Varanasi

Data
location India , Bangladesh
River system Ganges
Confluence of Alaknanda and Bhagirathi
30 ° 8 ′ 42 "  N , 78 ° 35 ′ 51"  E
Source height approx.  475  m
Association with Brahmaputra to Padma coordinates: 23 ° 48 ′ 0 ″  N , 89 ° 46 ′ 0 ″  E 23 ° 48 ′ 0 ″  N , 89 ° 46 ′ 0 ″  E
Mouth height m
Height difference approx. 469 m
Bottom slope approx. 0.18 ‰
length approx. 2620 km  (with junction Bhagirathi / Hugli )
Catchment area approx. 975,000 km² (without Hugli )
Discharge at the gauge Farakka
MNQ: mean discharge in April
MHQ: mean discharge in August
NNQ
MNQ
MQ
MHQ
HHQ
1181 m³ / s
1751 m³ / s
12.037 m³ / s
43.030 m³ / s
65.072 m³ / s
Left tributaries Varuna , Tamsa , Ramganga , Gomti , Ghaghara , Gandak , Koshi , Mahananda
Right tributaries Yamuna , Tamsa , Son
Big cities Kanpur , Prayagraj , Varanasi , Patna
Navigable on 631 km
The Ganges and its tributaries

The Ganges and its tributaries

Ganges delta

Ganges delta

The most important measuring point on the lowest Ganges (Padma): the Hardinge Bridge

The most important measuring point on the lowest Ganges (Padma): the Hardinge Bridge

Pilgrims on the Ganges

Pilgrims on the Ganges

Map from 1680 showing the lower course of the Ganges to the west

Map from 1680 showing the lower course of the Ganges to the west

The Ganges ( Sanskrit , f., गंगा or गङ्गा , Gaṅgā ) is the second largest river in India and Bangladesh ( South Asia ) with an average water flow of over 12,000 m³ / s . The over 2600 kilometers long river drains the great plain south of the Himalayas , one of the most densely populated areas on earth. The Ganges is the holiest river for the Hindus ; it is very heavily polluted by sewage and pollutants .

course

The Ganges and its tributaries drain the area between the main line of the Himalayan peaks and the northern mountain ranges of the Deccan, such as the Vindhya Mountains and Aravalli Mountains . In the Ganges plain, all rivers turn to the southeast and collect in the moderately meandering main stream, interspersed with sandbanks. When entering the Ganges Delta, several stream arms branch off south to the Bay of Bengal , while the main stream of the Ganges, called Padma from the crossing to Bangladesh , joins the significantly larger Brahmaputra , here called Jamuna . The combined river, meanwhile grown to be the most powerful river in Asia, also reaches the Bay of Bengal as the Lower Meghna .

Source rivers and upper reaches in the Himalayas

Even within the Himalayas, the longer Bhagirathi and the larger Alaknanda merge as source rivers to form the Ganges. This estuary at Devprayag in the Garhwal region is the lowest of five holy river estuaries ( Panch Prayag ) that line up as pilgrimage sites down the Alaknanda. Nevertheless, the source of the Bhagirathi, the glacier gate Gaumukh (“cow's mouth”) with the pilgrimage site Gangotri , is, at least mythologically, the actual source of the Ganges. There the river flows out of one of the largest glaciers in the Himalayas, the Gangotri glacier . At the pilgrimage and tourist town of Rishikesh , the Ganges leaves the canyon-like valleys of the Himalayas. In a final narrow valley, the river cuts through the Siwalik foothills of the Himalayas before reaching the Ganges plain near the pilgrimage town of Haridwar .

Ganges plain

When entering the Ganges plain, the large Ganges canal has been branching off to the right since 1856 , which feeds a system of irrigation canals over 6,000 kilometers long. It is mainly distributed in the Doab , the two-stream land between the Ganges, which flows south-west, and its most important tributary , the Yamuna (in the fitting meaning twin ), which runs parallel about 100 km further south-west. The most important city on the Upper Ganges is the industrial Kanpur . The confluence of both rivers at Prayagraj , Triveni Sangam - known as the "triple mouth" ( Sangama (Sanskrit): "mouth") has religious significance, as the mythical river Saraswati is said to flow out of the underground here .

In the further course of the Ganges passes Varanasi , the city with the greatest religious importance on the Ganges, and Patna , the largest city on the banks of the river; both cities are among the oldest settlements in India. The Ganges then receives several water-rich tributaries from the Himalayas from the left.

Ganges delta

The Ganges delta begins with the junction of the Bhagirathi (not to be confused with the right Ganges source river). It is the most important branch of the Ganges in the delta area, continues below the name Hugli and finally flows into the Bay of Bengal in the Indian Ocean . Kolkata (formerly Calcutta ) is located on its left bank . Since 1975, the Farakka barrage has led an enlarged part of the Ganges through a canal to the Bhagirathi, thereby burdening the relationship between India and Bangladesh. The main strand of the Ganges reaches its national territory a little below it and then meets the significantly larger Brahmaputra , which is called Jamuna in the section there .

The combined stream then picks up the Upper Meghna coming from the left as Padma , before reaching the Bay of Bengal as Lower Meghna in a branched estuary . The Ganges delta in the narrower sense extends from this estuary almost 300 kilometers further west to the Hugli estuary and is mainly traversed by waters that branch off from the Ganges. With around 56,700 km², it is the world's largest estuary delta . Extensive mangrove swamps , the so-called Sundarbans, can be found along the coast . The numerous waters are kept in motion mainly by the strong tides . The strong population pressure (outside the national park) has also led to the colonization of this amphibious landscape.

Because of the low gradient, the larger and smaller river arms in the Ganges delta are connected to one another - the Jalangi connects the rivers Padma and Hugli; the Bhairab connects the Jalangi with river arms further south.

River system

In the narrower sense, the name Ganges only describes the main part of the large collecting artery of the numerous bodies of water in the central part of the north Indian lowlands. However, it also stands for the river system as a whole, which is characterized by the unusually large-scale and rapid variability of the watercourses, with the result that the historically developed river names no longer match the current main streams.

Water network

From a hydrological point of view, the Ganges is the largest tributary of the river, the lower part of which is named Brahmaputra , Jamuna , Padma and Lower Meghna . At the confluence with this main stream, the Ganges (here already as Padma ) carries around 12,000 m³ / s of water and above the discharge to Bhagirathi near Farakka around 13,000 m³ / s. The Brahmaputra (Jamuna), on the other hand, carries around 20,100 m³ / s. Further upstream, above Prayagraj, it is not the Ganges, but the “ tributaryYamuna that flows here, the main hydrological branch of the system with a mean water flow that is half greater and a length that is around 250 kilometers greater. It feeds the Ganges 2634 m³ / s. Further upstream it is the Chambal , which, with its double water flow at the confluence with the Yamuna, represents the main strand. The current runoffs would be higher without the extensive drainage for irrigation, but with a few exceptions the relative weights of the individual rivers would not shift significantly.

The water network has different characteristics depending on the sub-landscape.

  • In the Ganges Basin, almost parallel flow paths dominate over the large alluvial fans from the Himalayas.
  • Tree-shaped water networks have formed in the Himalayas, which, however, pass through two conspicuous concentration lines: The main ridge of the Himalaya forms only local watersheds; many north-westerly watercourses intersect at intervals the line of the highest peaks, then take on further tributaries of the rain-rich southern roof and are again concentrated on a few antecedent breakthrough valleys by the foothills of the Siwaliks .
  • South of the Ganges plain, the water networks are less regular and are often mapped out by the fault lines of the Deccan plateau.

Water data

Due to the not very clear water system in the delta area, the information on water flow, length and catchment area differ.

Either the value of the Farakka station is taken as the characteristic water flow, as it delivers the highest value before the Bhagirathi branches off (11,000 to 17,000 m³ / s depending on the reference period), or the value of the station at the Hardinge Bridge shortly before the confluence of the main line Padma with the Jamuna in Bangladesh (10,800 m³ / s to 15,000 m³ / s). However, the discharge fluctuates extremely over the course of the year.

The length information rarely only refers to the section called Ganges . Usually the longer source river is included. Below the first division in the delta area, the information refers either to the Ganges up to the confluence with the Jamuna (approx. 2420 km), or they include the common course to the sea. Sometimes the Bhagirathi / Hugli is also measured, especially since this describes the exclusively Indian flow path (approx. 2620 km).

The catchment area is usually given as 935,000 km² (Farakka) or 975,000 km² (confluence with the Jamuna). If you include the delta area down the Hugli, the result is around 1,080,000 km².

Tributaries

Apart from the most important tributary Yamuna, the tributaries with more water flow towards the Ganges from the left. They mostly come from the Himalayas and alleviate the oxygen deficiency and pollutant concentration of the main stream. On the other hand, there is the greatest risk of flooding in the Ganges area on their banks.

Confluence of Alaknanda and Bhagirathi at Devprayag
( -> color of waters )
Surname Mouth
of
Discharge
(MQ)
[m³ / s]
Length
[km]
Catchment
area
[km²]
Source height
[m. ü. M.]
Mouth
height
[m. ü. M.]
estuarine
place
Source rivers
Alaknanda Left 440 240 12587 4350 460 Devprayag
Bhagirathi right 260 254 7820 4120 460 Devprayag
Tributaries
Ramganga Left 490 596 32493 3110 130 Ibrahimpur
Yamuna right 2940 1376 366223 6387 74 Sahon
Ghaghara Left 2980 1080 127950 4800 48 Chapra
Sun right 900 784 71259 600 46 Dinapur
Gandak Left 1640 630 46300 7620 44 Sonepur
Kosi Left 2160 835 95156 7000 34 Kursela
Burhi Gandak Left 320 12021 300

The natural water network has been greatly changed by a dense network of artificial watercourses. Ganges and Yamuna therefore lose large parts of their volume in irrigation canals; for example, the Ganges Canal branches at 295 m³ / s. from and the Yamuna Canal 218 m³ / s.

Hydrology

The flow regime of the Ganges is strongly seasonal and is shaped by the rainfall of the southwest monsoon . 84% of the precipitation falls from June to September. Despite the mitigating influence of the glacier meltwater from the Himalayas, the mean ratio of the lowest monthly discharge to the highest at the Farakka barrage is more than 1:21.

Average monthly discharge (in m³ / s) of the Farakka hydrological station (height: 19 m, catchment area: 833,000 km², based on the values ​​from 1949 to 1973):

Formation of the Ganges basin

In the course of the ongoing collision of the Indian subcontinent with the Eurasian plate , the Indian plate descends, which leads to the formation of an extensive fore-depth in front of the Himalayan folds as a collision front . It is constantly being filled up by the sediments from the Himalayas. The river system of the Ganges has developed in the eastern part of the lowlands.

The valley shapes on the upper reaches are characterized by strong fluvial erosion due to the strong ongoing uplift of the Himalayas and therefore form narrow valley profiles with slopes at risk of slipping, some of which are also gorge-like. The top source streams flow in trough valleys , the ice-age glaciers have left. After passing the last gorge through the edge chains of young sedimentary rocks, the river branches out, constantly shifting the stream channels and piling up extensive gravel and sand areas. In the further course, increasingly fine-grained, agriculturally more usable sediments dominate. Cities have arisen preferably on high, stable banks.

In the flat lowest part of the lowlands, the tectonic unrest can also lead to significant shifts in course. Up until the late 12th century, the Bhagirathi was the main arm of the Ganges, but it partly ran differently than it is today. Then the padma arm became more important; from the 16th century it was roughly equal and from the 18th century it was the main stream. These shifts, as well as the somewhat later shift of the Brahmaputra to the west, i.e. via today's Jamuna to the Padma, is explained by tectonic uplifts in the western Ganges delta and the Old Brahmaputra, especially after an earthquake in 1782 and a flood disaster in 1787 which the Tista has also shifted its course away from the Ganges towards the Jamuna, which is just forming. The Ganges has only been part of a larger electricity system since these recent relocations; previously it was an independent river.

Flora and fauna

The Ganges is the habitat of the rare and little researched Ganges dolphin , the Ganges crocodile and the Gangeshai , about which little is known either . Numerous mammals ( Bengal tigers , Axis deer , wild boar ), birds and reptiles live in the shallow estuary, particularly in the Sundarbans .

Religious meaning

The Ganga , as Indians call the Ganges or its personification as a goddess, is sacred to most Indian religions . The bath in him is supposed to cleanse of sins and promises absolution . If possible, many Hindus want to die on the Ganges - preferably in Varanasi - and have their ashes scattered in the river.

Economical meaning

Inland navigation is possible on the Ganges, but it has no traffic significance. The largest cities on the Ganges are Kanpur , Varanasi , Patna , Calcutta and Khulna .

The big cities along the Ganges get up to 70 percent of their drinking water from the river.

Wastewater pollution

The pollution of the river is enormous: every day over 5 million cubic meters of toxic waste water is discharged, in Calcutta alone 320 million liters into the Hugli arm of the Ganges . The exposure to E. coli bacteria is 2000 times higher than allowed in India and the water contains high concentrations of cyanides , arsenic , lead , zinc , chromium and mercury . Numerous body remains are added to the faecal waste water. Both of these facilitate the spread of cholera and typhus bacteria .

In addition, only a few sewage treatment plants work effectively, so that there, too, purified water mixes again with highly polluted water below the plants. In 1985 the Indian government launched a Ganga Action Plan with the aim of combating pollution. Despite high investments, the plan has largely failed, not least because the funds required to operate the systems were lacking. The Supreme Court of the northern Indian state of Uttarakhand ordered in March 2017 that the Ganges and its main tributary, Yamuna , be given legal entity status. The rivers are said to acquire "all appropriate rights, duties and responsibilities of a living person". This choice means that pollution or damage to rivers is equivalent to harm to a person. The court cited the example of New Zealand's Whanganui River , which also has full legal rights.

See also

literature

  • Ganges . In: Meyers Konversations-Lexikon . 4th edition. Volume 6, Verlag des Bibliographisches Institut, Leipzig / Vienna 1885–1892, p. 892.
  • KL Rao: India's Water Wealth. Orient Blackswan, 1979, ISBN 81-250-0704-0 . (Views)
  • Vijay Singh: The goddess who turns into a river. Kaufmann-Klett, 1994.
  • Ilija Trojanow : On the inner shores of India. A journey along the Ganges. Hanser, 2003, ISBN 3-446-20229-3 .
  • Lena Zühlke: Adoration and pollution of the corridor. Connection between ecological problems and the religious significance of the holy river. Regiospectra Verlag, Berlin 2013, ISBN 978-3-940132-50-5 .
  • Sudipta Sen: Ganges: The Many Pasts of an Indian River. Yale University Press, New Haven 2019, ISBN 978-0-3001-1916-9 .

Web links

Commons : Ganges  - collection of images, videos and audio files

Individual evidence

  1. Level data of the Ganges at Farakka
  2. GRDC level data
  3. Sharad K. Jain, Pushpendra K. Agarwal, Vijay P. Singh: Hydrology and water resources of India. New York 2007, p. 336.
  4. Sharad K. Jain, Pushpendra K. Agarwal, Vijay P. Singh: Hydrology and water resources of India. New York 2007, p. 338.
  5. The data in the literature scatter around this value between 10,850 m³ / s ( Water Profile of Bangladesh , according to FAO data) and 16,730 m³ / s (Pranab Kumar Parua: The Ganga: water use in the Indian subcontinent. ISBN 90-481 -3102-2 ).
  6. a b Shaw Lacy: Modeling the Efficacy of the Ganga Action Plan's Restoration of the Ganga River, India ( Memento of the original from January 28, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 5.5 MB) 2006, p. 53. @1@ 2Template: Webachiv / IABot / rivers.snre.umich.edu
  7. Jun Jian, Peter J. Webster, Carlos D. Hoyos: Large-scale controls on Ganges and Brahmaputra river discharge on intraseasonal and seasonal time-scales. (PDF; 4.1 MB) Quarterly Journ. R. Meteorol. Soc. 135, pp. 353-370, Atlanta 2009.
  8. Singh, Hasnain: Major ion chemistry and weathering control in a high altitude basin: Alaknanda River, Garhwal Himalaya, India ( Memento of the original from February 1, 2012 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 1.3 MB), 1998; Arun Kumar: Assessment of Cumulative Impact of Hydropower Projects in Alaknanda and Bhagirathi Basins (PDF; 5.6 MB), Chapter 7 Hydrology March 30, 2011 @1@ 2Template: Webachiv / IABot / www.iahs.info
  9. Measured in aerial photo material from Google Earth over the longest river route with tributary Dharani Gad. Length from Gaumukh : 240 km
  10. a b c d e f Sharad K. Jain, Pushpendra K. Agarwal, Vijay P. Singh: Hydrology and water resources of India. New York 2007
  11. fmis.bih.nic.in
  12. The Ganges at Farakka
  13. VN Mikhailov, MA Dotsenko: Processes of Delta Formation in the Mouth Area of ​​the Ganges and Brahmaputra Rivers ( Memento of the original from April 25, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 444 kB)  @1@ 2Template: Webachiv / IABot / www.aseanbiodiversity.info
  14. Ganga Action Plan ( Memento of the original from March 4, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.cag.gov.in
  15. Michael Safi, agencies: Ganges and Yamuna rivers granted same legal rights as human beings . In: The Guardian . March 21, 2017, ISSN  0261-3077 ( theguardian.com [accessed March 26, 2019]).