The Ganges or Ganga, is a trans-boundary river of India and Bangladesh. The 2,525 km (1,569 mi) river rises in the western Himalayas in the Indian state of Uttarakhand, and flows south and east through the Gangetic Plain of North India into Bangladesh, where it empties into the Bay of Bengal. It is the longest river of India and is the second greatest river in the world by water discharge. The Ganges basin is the most heavily populated river basin in the world, with over 400 million people and a population density of about 1,000 inhabitants per square mile (390 /km2).
The Ganges is the most sacred river to Hindus and is also a lifeline to millions of Indians who live along its course and depend on it for their daily needs. It is worshiped as the goddess Ganga in Hinduism. It has also been important historically: many former provincial or imperial capitals (such as Patliputra, Kannauj, Kara, Kashi, Allahabad, Murshidabad, Munger, Baharampur and Kolkata) have been located on its banks.
The Ganges was ranked among the five most polluted rivers of the world in 2007, with fecal coliform levels in the river near Varanasi more than one hundred times the official Indian government limits. Pollution threatens not only humans, but also more than 140 fish species, 90 amphibian species and the endangered Ganges river dolphin. The Ganga Action Plan, an environmental initiative to clean up the river, has been a major failure thus far, due to corruption and lack of technical expertise, lack of good environmental planning, Indian traditions and beliefs, and lack of support from religious authorities.
Course:
The Himalayan headwaters of the Ganges river in the Garhwal region of Uttarakhand, India. The headstreams and rivers are labeled in italics; the heights of the mountains, lakes, and towns are displayed in parentheses in meters. The Ganges begins at the confluence of the Bhagirathi and Alaknanda rivers. The Bhagirathi is considered to be the true source in Hindu culture and mythology, although the Alaknanda is longer. The headwaters of the Alakananda are formed by snowmelt from such peaks as Nanda Devi, Trisul, and Kamet. The Bhagirathi rises at the foot of Gangotri Glacier, at Gaumukh, at an elevation of 3,892 m (12,769 ft).
Although many small streams comprise the headwaters of the Ganges, the six longest and their five confluences are considered sacred. The six headstreams are the Alaknanda, Dhauliganga, Nandakini, Pindar, Mandakini, and Bhagirathi rivers. The five confluences, known as the Panch Prayag, are all along the Alaknanda. They are, in downstream order, Vishnuprayag, where the Dhauliganga joins the Alaknanda; Nandprayag, where the Nandakini joins; Karnaprayag, where the Pindar joins, Rudraprayag, where the Mandakini joins; and finally, Devprayag, where the Bhagirathi joins the Alaknanda to form the Ganges River proper.
Geology:
The Indian subcontinent lies atop the Indian tectonic plate, a minor plate within the Indo-Australian Plate. Its defining geological processes commenced seventy-five million years ago, when, as a part of the southern supercontinent Gondwana, it began a northeastwards drift lasting fifty million years across the then unformed Indian Ocean. The subcontinent's subsequent collision with the Eurasian Plate and subduction under it, gave rise to the Himalayas, the planet's highest mountains. In the former seabed immediately south of the emerging Himalayas, plate movement created a vast trough, which, having gradually been filled with sediment borne by the Indus and its tributaries and the Ganges and its tributaries, now forms the Indo-Gangetic Plain.
Hydrology:
The name Ganges is used for the river between the confluence of the Bhagirathi and Alaknanda rivers, in the Himalayas, and the India-Bangladesh border, near the Farakka Barrage and the first bifurcation of the river. The length of the Ganges is frequently said to be slightly over 2,500 km (1,600 mi) long, about 2,505 km (1,557 mi), to 2,525 km (1,569 mi), or perhaps 2,550 km (1,580 mi). In these cases the river's source is usually assumed to be the source of the Bhagirathi River, Gangotri Glacier at Gomukh, and its mouth being the mouth of the Meghna River on the Bay of Bengal. Sometimes the source of the Ganges is considered to be at Haridwar, where its Himalayan headwater streams debouch onto the Gangetic Plain.
Irrigation:
The Ganges and its tributaries, especially the Yamuna, have been used for irrigation since ancient times. Dams and canals were common in gangetic plain by fourth century BCE.
Dams and barrages:
A major barrage at Farakka was opened on 21 April 1975, It is located close to the point where the main flow of the river enters Bangladesh, and the tributary Hooghly (also known as Bhagirathi) continues in West Bengal past Kolkata. This barrage, which feeds the Hooghly branch of the river by a 26-mile (42 km) long feeder canal, and its water flow management has been a long-lingering source of dispute with Bangladesh.
Ecology and environment:
Human development, mostly agriculture, has replaced nearly all of the original natural vegetation of the Ganges basin. More than 95% of the upper Gangetic Plain has been degraded or converted to agriculture or urban areas. Only one large block of relatively intact habitat remains, running along the Himalayan foothills and including Rajaji National Park, Jim Corbett National Park, and Dudhwa National Park. As recently as the 16th and 17th centuries the upper Gangetic Plain harbored impressive populations of wild Asian elephants (Elephas maximus), tigers (Panthera tigris), Indian Rhinoceros (Rhinoceros unicornis), gaurs (Bos gaurus), barasinghas (Rucervus duvaucelii), sloth Bears (Melursus ursinus) and Indian lions.
In the 21st century there are few large wild animals, mostly deer, boars, wildcats, and small numbers of wolves, jackals, and foxes. Bengal tigers survive only in the Sundarbans area of the Ganges Delta. Crocodiles and barasingha are also found in the Sundarbans. The Sundarbands freshwater swamp ecoregion, however, is nearly extinct. Threatened mammals in the upper Gangetic Plain include the tiger, elephant, sloth bear, and chousingha (Tetracerus quadricornis). Fish are found in all the major rivers of the Ganges basin, and are a vital food source for many people. In the Bengal area common fish include featherbacks (Notopteridae family), barbs (Cyprinidae), walking catfish (Clarias batrachus), gouramis (Anabantidae), and milkfish (Chanos chanos). The critically endangered Ganges shark (Glyphis gangeticus) is also found in the river and other places in south Asia.
Length: 2,525 km (1,569 mi)
Basin: 1,080,000 km2 (416,990 sq mi)
