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Evolution
Geologists believe that a mighty river called Shiwalik or Indo-Brahma traversed the entire longitudinal extent of the Himalayas from Assam to Punjab and onwards to Sind, and finally discharged into the Gulf of Sind near lower Punjab during the Miocene period. The remarkable continuity of the Shiwalik and its lacustrine origin and alluvial deposits consisting of sands, silt, clay, boulders and conglomerates support this viewpoint. It is opined that in due course of time Indo–Brahma river was dismembered into three main drainage systems:
- The Indus and its five tributaries in the western part;
- The Ganga and its Himalayan tributaries in the central part; and
- The stretch of the Brahmaputra in Assam and its Himalayan tributaries in the eastern part.
The dismemberment was probably due to the Pleistocene upheaval in the western Himalayas, including the uplift of the Potwar Plateau (Delhi Ridge), which acted as the water divide between the Indus and Ganga drainage systems. Likewise, the downthrusting of the Malda gap area between the Rajmahal hills and the Meghalaya plateau during the mid-Pleistocene period, diverted the Ganga and the Brahmaputra systems to flow towards the Bay of Bengal.
Indus River System
Indus River is one of the chief river of southern Asia. From its source in Tibet, China, the Indus flows some 1,900 miles (3,100 km) through India and Pakistan to the Arabian Sea, an arm of the Indian Ocean. All of India's section of the river is in Kashmir. The river's drainage basin occupies 332,000 square miles (860,000 km2); most of it is in Pakistan.
Its tributaries are:
Jhelum
The Jhelum River has its source in the south-eastern region of Jammu and Kashmir, in a spring lying at Verinag. The length of Jhelum river is 480 miles. The river runs partly in Pakistan and partly in India. The source of the river is situated at the base of the Pir Panjal range in the south eastern region of the Kashmir plateau. The river runs through the Wular lake and Srinagar in India, prior to moving into the Punjab province of Pakistan.
Chenab
The Chenab River has its source at the meeting point of two rivers, the Chandra and the Bhaga. In Himachal Pradesh, the river is also called the Chandrabhaga. It flows parallely to the Pir Panjal Range. The river moves into the lands of Punjab in the vicinity of Akhnur and is subsequently connected with the Jhelum. It creates the border between the Rechna and the Jech Doabs. The Chenab also meets the Ravi and the Sutlej in Pakistan. The length of the Chenab River is 960 km.
Beas
The Beas originates from the Beas Kund near the Rohtang Pass at an elevation of 4,000 m above the mean sea level. The river flows through the Kullu valley and forms gorges at Kati and Lorji in the Dhauladhar range. It enters the Punjab plains near Pong. Then it takes southwesterly direction and meets the Satluj near Harike. The average annual flow of the Beas at Mandi is 15,800 million cubic meters. The Beas is 615 km long.
Ravi
The Ravi has its source in the Kullu hills near Rohtang Pass in Himachal Pradesh. Flowing in the northwest direction, it drains the area lying between the Pir Panjal and the Dhauladhar ranges. It enters Punjab plains near Madhopur and enters Pakistan 26km south of Amritsar. It debouches into Chenab at Sarai Sindhu near Rangpur. Its annual flow at Madhopur is 8,000 million cubic meters.
Satlej
The source of the river is the Rakshas Tal or Rakas Lake, which is linked to the Manasarovar Lake with a watercourse in Tibet. The river moves into Pakistan in the vicinity of Sulemanki and is subsequently met by the Chenab. The Satlej is approximately 1,500 km long.
Ganga River System
Ganga River Basin is one of the largest one and have high climatic, geographical and anthropological variations. The Ganga is the third longest river flowing through India after Indus and Brahamputra. Even then Ganga River basin is largest basin in India and occupies approximately 25 percent of the India’s land area. It is bounded in the north by the Himalayas and in the south by the Vindhya Range.
Among all river basins in India, Ganga river basin has maximum value of estimated utilizable flow of surface water i.e.50% approximately out of the average annual runoff of 501.643 cu Km. On the other hand the Brahamputra with the largest average annual runoff of 537.067 cu.Km contributes only 4% of utilizable flow of surface water. This clearly indicates the high utilitarian value of Ganga River Basin in quantitative terms.
The Ganges rises in the southern Himalayas on the Indian side of the border with the Tibet Autonomous region of China. Its five headstreams—the Bhagirathi, Alaknanda, Mandakini, Dhauliganga, and Pindar—all rise in the northern mountainous region of Uttarakhand state. Of these, the two main headstreams are the Alaknanda (the longer of the two), which rises about 30 miles (50 km) north of the Himalayan peak of Nanda Devi, and the Bhagirathi, which originates about 10,000 feet (3,000 metres) above sea level in a subglacial meltwater cave at the base of the Himalayan glacier known as Gangotri. Gangotri itself is a sacred place for Hindu pilgrimage. The true source of the Ganges, however, is considered to be at Gaumukh, about 13 miles (21 km) southeast of Gangotri.
The Alaknanda and Bhagirathi unite at Devaprayag to form the main stream known as the Ganga, which cuts through the Outer (southern) Himalayas to emerge from the mountains at Rishikesh. It then flows onto the plain at Haridwar, another place held sacred by the Hindus.
The volume of the Ganges increases markedly as it receives more tributaries and enters a region of heavier rainfall, and it shows a marked seasonal variation in flow. From April to June the melting Himalayan snows feed the river, while in the rainy season from July to September the rain-bearing monsoons cause floods. During winter the river’s flow declines.
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Tributaries:
The Yamuna and the Son are its major right bank tributaries. The important left bank tributaries are the Ramganga, the Gomati, the Ghaghara, the Gandak, the Kosi and the Mahananda in the order from west to east.
Yamuna
The Yamuna is the biggest tributary of the River Ganges in North India. The river originates from the Yamunotri Glacier on the southwestern sides of the Banderpooch crests of the Lower Himalayan Mountain Range. During its itinerary, the river passes through states like Uttar Pradesh, Uttarakhand, and Haryana. The famous river meets the Ganges at Triveni Sangam in Allahabad, a popular pilgrimage spot for the Hindus. The biggest and longest tributary of the Yamuna is the Tons River. Other tributaries of the Yamuna include the Betwa, Chambal, Sindh, Ken, Sarda, Hindon, Giri, Kunta, Hanuman Ganga, Rishiganga, and Kunta Rivers. The catchment area of Yamuna comprises the most of the Ganges Basin. The river traverses cities like Mathura, Delhi, Agra, Etawah, and Kalpi.
Son
The Son is a large south bank tributary of the Ganga, originating in the Amarkantak plateau. After forming a series of waterfalls at the edge of the plateau, it turns northeastward. It reaches Arrah, west of Patna, to join the Ganga. The important tributaries of the Son are the Johilla, the Gopat, the Rihand, the Kanhar and the North Koel.
Ramganga
The Ramganga is a small river rising in the Garhwal hills near Kalagarh. It changes its course to the southwest direction after crossing the Shiwalik and enters into the plains of Uttar Pradesh near Najibabad. Finally, it joins the Ganga near Kannauj. Its main tributaries are the Khoh, the Gangan, the Aril, the Kosi, and the Deoha (Gorra).
Ghaghara
The Ghaghara originates in the glaciers of Mapchachungo near Gurla Mandhata peak south of Mansarovar. It is known as Karnali in western Nepal. After collecting the waters of its tributaries – Tila, Seti and Beri, it comes out of the mountain, cutting a deep gorge at Shishapani. The river Sarda (Kali or Kali Ganga) joins it in the plain before it finally meets the Ganga at Chhapra. Its other tributaries are the Sarju and the Rapti. Its average annual flow is 94,000 million cubic meter.
Gantak
It rises at 7620 m in Tibet near the Nepal border and overlooks the Dhaulagiri. It is distinguished for the deep gorge across which it flows and for a large hydroelectric facility in Nepal. This river also provides water for a major Irrigation cum Hydroelectric power facility at the Indo-Nepal border at Valmikinagar. The river has a total catchment area of 46,300 sqkm out of which 7620 sqkm is located in India. The Gandaki River is mentioned in the ancient Indian epic Mahabharata.
Kosi
It is an antecedent river with its source to the north of Mount Everest in Tibet, where its main stream Arun rises. The Kosi River is a trans-boundary river, running across important cities in Bihar and Nepal such as Biratnagar, Purnia, and Katihar. After crossing the Central Himalayas in Nepal, it is joined by the Sun Kosi from the West and the Tamur Kosi from the east. It forms Sapt Kosi after uniting with the river Arun at Triveni. Soon after debouching onto the plain the river becomes sluggish due to heavy load. The river channel is braided and it shifts its course frequently. This causes devastating floods. Thus the Kosi is known as ‘the Sorrow of Bihar’. Hanuman Nagar barrage has been constructed in 1965 to tame the river. The Kosi joins Ganga near Kursala.
Brahmaputra river system
The Brahmaputra basin covers an area of 5,80,000 Sq. Km of which 1,94,413 Sq. Km falls in India. In India, the basin lies in the states of Arunachal Pradesh, Assam, Nagaland, Meghalaya, Sikkim and West Bengal. Brahmaputra is a perennial river, feed by snow as well as by rain.
The Brahmaputra rolls down the plain of Assam east to west for a distance of 640 km up to Bangladesh border. Through its course, the river receives innumerable tributaries coming out of the northern, northeastern and the southern hill ranges. The mighty river with a well-knit network of tributaries drains an area of 56,480 Sq. Km of the state accounting for 72 per cent of its total geographical area. Most of the right bank tributaries of Brahmaputra are snow as well rain feed and are perennial. Although the left bank tributaries are mainly rain feed but perennial in nature.
It is the fourth largest river in the world in term of average water discharge at the mouth with a flow of 19,830 m3s-1. The river carries 82 per cent of its annual flow during the rainy season (May through October).
The principle tributaries of the river are:
Tista River
It rises in the Himalayas near Chunthang in Sikkim (India), flows to the south, cutting a deep gorge through the Siwalik Hills east of Darjiling (in West Bengal, India), and turns southeast to run through the Sivok Khola pass onto the plains of West Bengal. Originally, the river continued southward to empty directly into the upper Padma River (Ganges [Ganga] River). About 1787, however, the river changed its course to flow eastward, crossing the Rangpur region of Bangladesh to join the Jamuna River near Chilmari after a total course of about 200 miles (320 km).
The flow of the Tista is greatest during the summer (June to September), when the monsoon rains are heaviest and glaciers supply abundant meltwater. Its lower reaches are marked by flooding and frequent, violent course changes; navigation is impaired by shoals and quicksand near the junction with the Jamuna. The Tista Barrage is a dam that helps to provide irrigation for the plains between the upper Padma and the Jamuna.
Lohit River
The Lohit River originates in eastern Tibet, in the Zayal Chu range and surges through Arunachal Pradesh for two hundred kilometers, before emptying itself in the plains of Assam. Uncontrolled and turbulent is the features of the Lohit River. The Lohit River has derived its name because of its vigorous nature and thus it is also called the river of blood. The lateritic soil of the river forms its surrounding demography. The river flows through the Mishmi Hills, to meet the Siang at the head of the Brahmaputra valley.
Manas River
The Manas River is one of the most important tributary of the Brahmaputra. It originates in Bhutan, flows through southern Bhutan and Assam and finally joins the Brahmaputra in Jogighopa. The Manas River has a length of 376 kms and is characterized by hilly steep forests in the upper reaches and plain on the lower end of the river.
Subansiri River
It is another important tributary of the Brahmaputra which originates in the Himalayas in China and flows through Tibet and India. It has a length of 442 kms and joins the Brahmaputra in Lakhimpur district of Assam.
Dhansiri River
It originates in the Laisang peak of Nagaland and flows through Dimapur district of Nagaland and Golaghat district of Assam before joining the Brahmaputra just 5 kms away from the Kaziranga Wildlife Sanctuary. Earlier, the Dhansiri River used to flow through the Kaziranga National Park, but with time it has changed course to meet the Brahmaputra 5 kms away. This abandoned course is now called the Mora Dhansiri.
