The Ganges (in India: Ganga; in Bangladesh: Padma) is a trans-boundary river of Asia which flows through India and Bangladesh. The river rises in the western Himalayas in the Indian state of Uttarakhand. It flows south and east through the Gangetic plain of North India, receiving the right-bank tributary, the Yamuna, which also rises in the western Indian Himalayas, and several left-bank tributaries from Nepal that account for the bulk of its flow. "The tributaries that originate in Nepal and China, including the Kosi, Gandaki, Kamala, Bagmati, Kamali and Mahakali, account for about 45 percent of the Ganges flow." In West Bengal, India, a feeder canal taking off from its right bank diverts half of its flow southwards, artificially connecting it to the Hooghly River. The Ganges continues into Bangladesh, its name changing to the Padma. It is then joined by the Jamuna, the lower stream of the Brahmaputra, and eventually the Meghna, forming the major estuary of the Ganges Delta, and emptying into the Bay of Bengal. The Ganges–Brahmaputra–Meghna system is the second-largest river on earth by discharge.
The main stem of the Ganges begins at Devprayag, at the confluence of the Alaknanda, which is the source stream in hydrology on account of its greater length, and the Bhagirathi, which is considered the source stream in Hindu mythology.
The Ganges is a lifeline to hundreds of millions of people who live in its basin and depend on it for their daily needs. It has been important historically, with many former provincial or imperial capitals such as Pataliputra, Kannauj, Sonargaon, Dhaka, Bikrampur, Kara, Munger, Kashi, Patna, Hajipur, Kanpur, Delhi, Bhagalpur, Murshidabad, Baharampur, Kampilya, and Kolkata located on its banks or those of its tributaries and connected waterways. The river is home to approximately 140 species of fish, 90 species of amphibians, and also reptiles and mammals, including critically endangered species such as the gharial and South Asian river dolphin. The Ganges is the most sacred river to Hindus. It is worshipped as the goddess Ganga in Hinduism.
The Ganges is threatened by severe pollution. This not only poses a danger to humans but also to many species of animals. The levels of fecal coliform bacteria from human waste (feces and urine) in the river near Varanasi are more than 100 times the Indian government's official limit. The Ganga Action Plan, an environmental initiative to clean up the river, has been considered a failure"Clean Up Or Perish", The Times of India, 19 March 2010 which is variously attributed to corruption, a lack of care from the government, poor technical expertise, poor environmental planning, and a lack of support from religious authorities.
Course The upper phase of the river Ganges begins at the confluence of the Bhagirathi and Alaknanda rivers in the town of Devprayag in the Garhwal division of the Indian state of Uttarakhand. The Bhagirathi is considered to be the source in Hindu culture and mythology, although the Alaknanda is longer, and therefore, hydrologically the source stream. The headwaters of the Alakananda are formed by snow melt from peaks such as Nanda Devi, Trisul, and Kamet. The Bhagirathi rises at the foot of Gangotri Glacier at Gomukh, at an elevation of and was mythologically referred to as residing in the matted locks of Shiva; symbolically Tapovan, which is a meadow of ethereal beauty at the feet of Mount Shivling, just away.
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. Their 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.
After flowing for through its narrow Himalayan valley, the Ganges emerges from the mountains at Rishikesh, then debouches onto the Gangetic Plain at the pilgrimage town of Haridwar. At Haridwar, a headworks diverts some of its water into the Ganges Canal, which irrigates the Doab region of Uttar Pradesh,: "Nowhere is this more in evidence than in the construction of the canal headwork's and particularly the Ganges canal head at Hardwar. The advantage of choosing this site for the headworks was that it took off at a high point (where the river emerges from the hills) and thus avoided the problem of constructing a dam on the sandy bed of the river (the bed was still rocky at Hardwar) and of 'lifting', via embankments, the canal out of the khadir several miles wide through which the Ganges river flowed at a lower level than the Doab plains." whereas the river, whose course has been roughly southwest until this point, now begins to flow southeast through the plains of northern India.
The Ganges river follows a arching course passing through the cities of Bijnor, Kannauj, Farukhabad, and Kanpur. Along the way it is joined by the Ramganga, which contributes an average annual flow of about to the river. The Ganges joins the long River Yamuna at the Triveni Sangam at Prayagraj (previously Allahabad), a confluence considered holy in Hinduism. At their confluence the Yamuna is larger than the Ganges contributing about 58.5% of the combined flow, with an average flow of .
Now flowing east, the river meets the long Tamsa River (also called Tons), which flows north from the Kaimur Range and contributes an average flow of about . After the Tamsa, the long Gomti River joins, flowing south from the Himalayas. The Gomti contributes an average annual flow of about . Then the long Ghaghara River (Karnali River), also flowing south from the Himalayas of Tibet through Nepal joins. The Ghaghara (Karnali), with its average annual flow of about , is the largest tributary of the Ganges by discharge. After the Ghaghara confluence, the Ganges is joined from the south by the long Son River, which contributes about . The long Gandaki River, then the long Kosi River, join from the north flowing from Nepal, contributing about and , respectively. The Kosi is the third largest tributary of the Ganges by discharge, after Ghaghara (Karnali) and Yamuna. The Kosi merges into the Ganges near Kursela in Bihar.Along the way between Prayagraj and Malda, West Bengal, the Ganges river passes the towns of Chunar, Mirzapur, Varanasi, Ghazipur, Ara, Patna, Chapra, Hajipur, Mokama, Begusarai, Munger, Sahibganj, Rajmahal, Bhagalpur, Ballia, Buxar, Simaria, Sultanganj, and Farakka. At Bhagalpur, the river begins to flow south-southeast and at Farakka, it begins its attrition with the branching away of its first distributary, the long Bhāgirathi-Hooghly, which goes on to become the Hooghly River. Just before the border with Bangladesh the Farakka Barrage controls the flow of Ganges, diverting some of the water into a feeder canal linked to the Hooghly for the purpose of keeping it relatively silt-free. The Hooghly River is formed by the confluence of the Bhagirathi River and Ajay River at Katwa, and Hooghly has a number of tributaries of its own. The largest is the Damodar River, which is long, with a drainage basin of . The Hooghly River empties into the Bay of Bengal near Sagar Island. Between Malda and the Bay of Bengal, the Hooghly river passes the towns and cities of Murshidabad, Nabadwip, Kolkata and Howrah.After entering Bangladesh, the main branch of the Ganges river is known as the Padma. The Padma is joined by the Jamuna River, the largest distributary of the Brahmaputra. Further downstream, the Padma joins the Meghna River, the converged flow of Surma-Meghna River System taking on the Meghna's name as it enters the Meghna Estuary, which empties into the Bay of Bengal. Here it forms the Bengal Fan, the world's largest submarine fan, which alone accounts for 10–20% of the global burial of organic carbon.
The Ganges Delta, formed mainly by the large, sediment-laden flows of the Ganges and Brahmaputra rivers, is the world's largest delta, at about . It stretches along the Bay of Bengal.
Only the Amazon and Congo rivers have a greater average discharge than the combined flow of the Ganges, the Brahmaputra, and the Surma-Meghna river system. In full flood only the Amazon is larger.
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 mountain ranges. 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.
The Indo-Gangetic Plain is geologically known as a foredeep or foreland basin.
Hydrology
Major left-bank tributaries include the Gomti River, Ghaghara River, Gandaki River and Kosi River; major right-bank tributaries include the Yamuna River, Son River, Punpun and Damodar. The hydrology of the Ganges River is very complicated, especially in the Ganges Delta region. One result is different ways to determine the river's length, its discharge, and the size of its drainage basin.
The name Ganges is used for the river between the confluence of the Bhagirathi and Alaknanda rivers, in the Himalayas, and the first bifurcation of the river, near the Farakka Barrage and the India-Bangladesh Border. The length of the Ganges is frequently said to be slightly over long, about , or . 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.
In some cases, the length of the Ganges is given by its Hooghly River distributary, which is longer than its main outlet via the Meghna River, resulting in a total length of about , if taken from the source of the Bhagirathi, or , if from Haridwar to the Hooghly's mouth. In other cases the length is said to be about , from the source of the Bhagirathi to the Bangladesh border, where its name changes to Padma.
For similar reasons, sources differ over the size of the river's drainage basin. The basin covers parts of four countries, India, Nepal, China, and Bangladesh; eleven Indian states, Himachal Pradesh, Uttarakhand, Uttar Pradesh, Madhya Pradesh, Chhattisgarh, Bihar, Jharkhand, Punjab, Haryana, Rajasthan, West Bengal, and the Union Territory of Delhi. The Ganges basin, including the delta but not the Brahmaputra or Meghna basins, is about , of which is in India (about 80%), in Nepal (13%), in Bangladesh (4%), and in China (3%). Sometimes the Ganges and Brahmaputra–Meghna drainage basins are combined for a total of about or . The combined Ganges-Brahmaputra-Meghna basin (abbreviated GBM or GMB) drainage basin is spread across Bangladesh, Bhutan, India, Nepal, and China.