River1

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 that resembles a tree's branching roots. It occurs when a stream receives water from tributaries, which are fed by smaller tributaries. Tributaries join larger streams at acute angles (less than 90°). E.g., The rivers of the Northern Plains: Indus, Ganga, and Brahmaputra.
• Trellis: This type of drainage pattern is formed when primary tributaries of main rivers flow parallel to each other and secondary tributaries join them at right angles. E.g., The rivers in the upper part of the Himalayan region: Indus, Ganga, and Brahmaputra.
• Radial: This type of drainage pattern is a pattern of streams and rivers that radiate outward from a central high point. It's common around volcanoes and other conically shaped features. E.g., The rivers like Narmada, Son, and Mahanadi originating from Amarkantak Hills.
• Centripetal: It is just the opposite of the radial pattern. The 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

They are perennial rivers (flow throughout the year) and they do not depend on monsoon for their water flow. They originate from glaciers in the Himalayas. They have long courses from source to sea. Three major Himalayan Rivers are: Indus, Ganga, Brahmaputra (originating from northern mountain ranges).

Peninsular River System

They are ephemeral (they are seasonal rivers). They have shorter and shallower course. Some major Peninsular Rivers are: Narmada, Tapi, Godavari, Krishna, etc.

Indus River System

Map 1: Indus River System

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

Origin: Bokhar Chu Glacier (Tibet) in the Kailash mountain range near Lake Mansarovar and it enters India at Demchok (Ladakh).

Flows through: China → India → Pakistan

Drains into: Arabian Sea

In Tibet, it is known as 'Singi Khamban' (meaning: Lion's mouth).

Tributaries:

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

Indus Water Treaty (1960)

This treaty was signed between India and Pakistan in Karachi (mediated by World Bank). It has been suspended by India in 2025 after Pooncham attack.

• The Treaty Allocates the Rivers to the Countries:
  • Western Rivers: Indus, Jhelum, and Chenab to Pakistan (and 20% used by India)
  • Eastern Rivers: Ravi, Beas, and Sutlej to India (80% water used by India and 20% used by Pakistan)
• Doab: It refers to the area of land situated between two rivers.
  • Indus + Jhelum: Sindh Sagar Doab
  • Jhelum + Chenab: Jech Doab
  • Chenab + Ravi: Rechna Doab
  • Ravi + Beas: Bari Doab
  • Beas + Sutlej: Bist Doab

Panchmah: It refers to the confluence of five rivers: Punjab → Jhelum, Chenab, Ravi, Beas, Sutlej

Ganga River System

Map 2: Ganga River System

Length: 2,525 km (longest river and has the largest river basin in India).

Origin: Gangotri Glacier (Gaumukh, Uttarakhand).

Drains into: Bay of Bengal as National river of India in 2008. The water from Ganga was declared as remains fresh due to the presence of Bacteriophage viruses.

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

Tributaries of Indus River

• Jhelum: Jhelum river meanders in its youthful stage. Ancient Name: Vitasta. Origin: Verinag (Jammu & Kashmir). Srinagar is located on the bank of Jhelum river. Wular lake (largest freshwater lake in India) is fed by Jhelum river.
• Chenab: Chenab river is formed by the confluence of two rivers - Chandra and Bhaga in Lahaul Valley. Ancient Name: Asikni. Origin: Baralacha La Pass. It is the largest tributary of Indus.
• Ravi: Ancient Name: Purushni. Origin: Rohtang Pass. It is a transboundary river — it flows through both India and Pakistan.
• Beas: Ancient Name: Vipasha. Origin: Rohtang Pass. It is the only tributary of Indus that does not enter Pakistan. It joins Indus near Harike (Punjab).
• Sutlej: Ancient Name: Shutudri. Origin: Rakshastal Lake (Mansarovar Lake, Tibet). It enters India through Shipki La Pass. It is the longest tributary of Indus river. In Tibet it is known as Langquenzangbo.

Brahmaputra River System

Map 3: Brahmaputra River System

Length: 2,900 km (in India)

Origin: Angsi Glacier (Tibet)

Originates from Mhow Plateau (Janapav Hills) of Madhya Pradesh.

It is well-known for its badland topography (due to ravines formed by gully erosion).

Tributaries: Banas, Shipra, Kalisindh, Parvati

It passes through: Uttarakhand, Uttar Pradesh (longest), and West Bengal: Kanpur → Prayagraj → Varanasi → Patna (in west to east order).

Famous Confluences (Prayags) Formed:

• Devprayag: Alaknanda + Bhagirathi (meets to form Ganga).
• Rudraprayag: Alaknanda + Mandakini.
• Karnaprayag: Alaknanda + Pindar.
• Nandaprayag: Alaknanda + Nandakini.
• Vishnuprayag: Alaknanda + Dhauliganga.

Ganga splits into two branches near Murshidabad, West Bengal → Padma river (flows through Bangladesh) and Bhagirathi-Hugli river (flows through West Bengal).

The Ganga is known as Padma (in Bangladesh), where it meets Brahmaputra (Jamuna) to form Meghna river and finally drains into Bay of Bengal forming Sundarban Delta.

Farakka Agreement (1996)

It is a treaty between India and Bangladesh to share the Ganges river water at the Farakka Barrage where it divides into Hugli river.

Mayurkashi, Kangsabati, Damodar, and Rupnarayan are tributaries of Hugli.

Tributaries of Ganga

• Right Bank Tributaries
  • Yamuna: Length: 1,370 km (longest tributary of Ganga in the Northern Plains). Origin: Yamunotri Glacier, Banderpoonch Peak (Uttarakhand). Tributaries: Chambal, Sindh, Betwa, Ken, Tons (largest tributary of Yamuna).
• Chambal River: Originates from Mhow Plateau (Janapav Hills) of Madhya Pradesh. It is well-known for its badland topography (due to ravines formed by gully erosion). Tributaries: Banas, Shipra, Kalisindh, Parvati