Himalayan Drainage Details

• Ganga, the Indus and the Brahmaputra river basins
• Rivers of this system are perennial
• River Kosi, also known as the sorrow of Bihar‘, has been notorious for frequently changing its course.

It is opined that in due course of time Indo– Brahma river was dismembered into three main drainage systems:

1. the Indus and its five tributaries in the western part;
2. the Ganga and its Himalayan tributaries in the central part; and
3. 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 down- thrusting 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.

The Indus System

• One of the largest river basins of the world
• Originates from a glacier near Bokhar Chu (31°15′ N latitude and 81°40′ E longitude) in the Tibetan region at an altitude of 4,164 m in the Kailash Mountain range.
• In Tibet, it is known as Singi Khamban; or Lion‘s mouth.
• Enters into Pakistan near Chillar in the Dardistan region
• The Jhelum, an important tributary of the Indus, rises from a spring at Verinag situated at the foot of the Pir Panjal in the south-eastern part of the valley of Kashmir.
• It flows through Srinagar and the Wular Lake before entering Pakistan through a deep narrow gorge.
• It joins the Chenab near Jhang in Pakistan.
• The Chenab is the largest tributary of the Indus. formed by two streams, the Chandra and the Bhaga, which join at Tandi near Keylong in Himachal Pradesh.
• Hence, it is also known as Chandrabhaga.
• Satluj originates in the Rakas Lake near Mansarovar at an altitude of 4,555 m in Tibet where it is known as Langchen Khambab.
• It flows almost parallel to the Indus for about 400 km before entering India, and comes out of a gorge at Ropar.
• It passes through the Shipki La on the Himalayan ranges and enters the Punjab plains.
• It is an antecedent river.
• It is a very important tributary as it feeds the canal system of the Bhakra Nangal project.

The Ganga System

• Rises in the Gangotri glacier near Gaumukh (3,900 m) in the Uttarkashi district of Uttarakhand.
• Here, it is known as the Bhagirathi.
• At Devaprayag, the Bhagirathi meets the Alaknanda; hereafter, it is known as the Ganga.
• The Alaknanda has its source in the Satopanth glacier above Badrinath
• The Ganga enters the plains at Haridwar.
• From here, it flows first to the south, then to the south-east and east before splitting into two distributaries, namely the Bhagirathi and the Hugli.
• 2,525 km- Uttarakhand (110 km) and Uttar Pradesh (1,450 km), Bihar (445 km) and West Bengal (520 km).
• The Son is its major right bank tributary.
• The important left bank tributaries are the Ramganga, the Gomati, the Ghaghara, the Gandak, the Kosi and the Mahananda.
• The river finally discharges itself into the Bay of Bengal near the Sagar Island.
• The Yamuna, the western most and the longest tributary of the Ganga, has its source in the Yamunotri glacier on the western slopes of Bandarpunch range (6,316 km).
• It joins the Ganga at Prayag (Allahabad).
• The Chambal rises near Mhow in the Malwa plateau of Madhya Pradesh and flows northwards through a gorge up wards of Kota in Rajasthan, where the Gandhisagar dam has been constructed.
• From Kota, it traverses down to Bundi, Sawai Madhopur and Dholpur, and finally joins the Yamuna. The Chambal is famous for its badland topography called the Chambal ravines.
• The Gandak comprises two streams, namely Kaligandak and Trishulganga. It rises in the Nepal Himalayas between the Dhaulagiri and Mount Everest and drains the central part of Nepal.
• It enters the Ganga plain in Champaran district of Bihar and joins the Ganga at Sonpur near Patna
• The Damodar occupies the eastern margins of the Chotanagpur Plateau where it flows through a rift valley and finally joins the Hugli. The Barakar is its main tributary. Once known as the sorrow of Bengal‘, the Damodar has been now tamed by the Damodar Valley corporation, a multipurpose project.
• The Mahananda is another important tributary of the Ganga rising in the Darjiling hills. It joins the Ganga as its last left bank tributary in West Bengal
• 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 reaches Arrah, west of Patna, to join the Ganga.

The Brahmaputra System

• • Origin in the Chemayungdung glacier of the Kailash range near the Mansarovar lake.
  • Tibet, where it is known as the Tsangpo, which means the purifier.‘
  • The Rango Tsangpo is the major right bank tributary of this river in Tibet.
• Enters India west of Sadiya town in Arunachal Pradesh.

• Flowing southwest, it receives its main left bank tributaries, viz., Dibang or Sikang and Lohit; thereafter, it is known as the Brahmaputra.
• The Brahmaputra receives numerous tributaries in its 750 km long journey through the Assam valley.
• Its major left bank tributaries are the Burhi Dihing and Dhansari (South) whereas the important right bank tributaries are the Subansiri, Kameng, Manas and Sankosh.
• The Subansiri which has its origin in Tibet, is an antecedent river.
• The Brahmaputra enters into Bangladesh near Dhubri and flows southward.
• In Bangladesh, the Tista joins it on its right bank from where the river is known as the Yamuna.
• It finally merges with the river Padma, which falls in the Bay of Bengal.