River 2

Himalayan River System

Drainage Pattern

Drainage pattern refers to the system of flow of surface water mainly through the forms of rivers and basins.

The drainage system depends upon factors such as slope of land, geological structure, amount of volume of water, and velocity of water.

Different Drainage Patterns

• Dendritic: The most common drainage pattern resembling a tree's branching roots. Occurs when a stream receives water from tributaries fed by smaller tributaries. Tributaries join larger streams at acute angles (less than 90°). E.g., Indus, Ganga, Brahmaputra.
• Trellis: Formed when primary tributaries flow parallel and secondary tributaries join at right angles. E.g., Upper Himalayan region rivers: Indus, Ganga, Brahmaputra.
• Radial: Streams and rivers radiate outward from a central high point, common around volcanoes. E.g., Narmada, Son, Mahanadi from Amarkantak Hills.
• Centripetal: Opposite of radial, streams flow toward a central depression/basin. E.g., Loktak Lake (Manipur).

Indian Drainage System

The Indian river system can be broadly classified as:

1. Himalayan River System
2. Peninsular River System

Himalayan River System

Perennial rivers flowing year-round, not dependent on monsoon. Originate from Himalayan glaciers with long courses. Major rivers: Indus, Ganga, Brahmaputra.

Peninsular River System

Ephemeral (seasonal) rivers with shorter, shallower courses. Major rivers: Narmada, Tapi, Godavari, Krishna.

Indus River System

Map 1: Indus River System

Length: 2,880 km (1,114 km in India)

Origin: Bokhar Chu Glacier (Tibet), Kailash range near Lake Mansarovar, enters India at Demchok (Ladakh).

Flows through: China → India → Pakistan

Drains into: Arabian Sea

In Tibet: Known as 'Singi Khamban' (Lion's mouth).

Tributaries:

• Left Bank: Jhelum, Chenab, Ravi, Beas, Sutlej
• Right Bank: Shyok, Gilgit, Hunza
• Leh is on the banks of Indus.

Indus Water Treaty (1960)

Signed between India and Pakistan (Karachi, mediated by World Bank), suspended by India in 2025 after Pooncham attack.

• River Allocation: Western Rivers (Indus, Jhelum, Chenab) to Pakistan (20% India), Eastern Rivers (Ravi, Beas, Sutlej) to India (80% India, 20% Pakistan).
• Doab: Area between two rivers. Examples: Sindh Sagar, Jech, Rechna, Bari, Bist Doabs.

Panchmah: Confluence of five rivers: Jhelum, Chenab, Ravi, Beas, Sutlej (Punjab).

Ganga River System

Map 2: Ganga River System

Length: 2,525 km (longest river, largest basin in India)

Origin: Gangotri Glacier (Gaumukh, Uttarakhand)

Drains into: Bay of Bengal (National river since 2008), water stays fresh due to Bacteriophage viruses.

Some Himalayan rivers are antecedent (follow original course despite geological changes). E.g., Sutlej, Kosi, Indus, Ganga.

Tributaries of Indus River

• Jhelum: Meanders in youthful stage. Ancient Name: Vitasta. Origin: Verinag (J&K). Srinagar and Wular Lake (largest freshwater lake) are associated.
• Chenab: Formed by Chandra and Bhaga (Lahaul Valley). Ancient Name: Asikni. Origin: Baralacha La Pass. Largest Indus tributary.
• Ravi: Ancient Name: Purushni. Origin: Rohtang Pass. Transboundary river (India, Pakistan).
• Beas: Ancient Name: Vipasha. Origin: Rohtang Pass. Joins Indus near Harike (Punjab), doesn’t enter Pakistan.
• Sutlej: Ancient Name: Shutudri. Origin: Rakshastal Lake (Tibet). Enters India via Shipki La Pass. Longest Indus tributary, known as Langquenzangbo in Tibet.

Brahmaputra River System

Map 3: Brahmaputra River System

Length: 2,900 km (in India)

Origin: Angsi Glacier (Tibet), also from Mhow Plateau (Janapav Hills, Madhya Pradesh)

Known for badland topography due to gully erosion. Tributaries: Banas, Shipra, Kalisindh, Parvati.

Passes through: Uttarakhand, Uttar Pradesh, West Bengal (Kanpur → Prayagraj → Varanasi → Patna).

Famous Confluences (Prayags)

• Devprayag: Alaknanda + Bhagirathi (forms Ganga)
• Rudraprayag: Alaknanda + Mandakini
• Karnaprayag: Alaknanda + Pindar
• Nandaprayag: Alaknanda + Nandakini
• Vishnuprayag: Alaknanda + Dhauliganga

Ganga splits near Murshidabad (West Bengal) into Padma (Bangladesh) and Bhagirathi-Hugli. Meets Brahmaputra (Jamuna) to form Meghna, draining into Bay of Bengal (Sundarban Delta).

Farakka Agreement (1996)

Treaty between India and Bangladesh to share Ganges water at Farakka Barrage, dividing into Hugli. Tributaries: Mayurkashi, Kangsabati, Damodar, Rupnarayan.

Tributaries of Ganga

• Right Bank Tributaries
  • Yamuna: Length: 1,370 km (longest Ganga tributary in Northern Plains). Origin: Yamunotri Glacier (Banderpoonch Peak). Tributaries: Chambal, Sindh, Betwa, Ken, Tons.
• Chambal River: Origin: Mhow Plateau (Madhya Pradesh). Known for badland topography. Tributaries: Banas, Shipra, Kalisindh, Parvati.