India  Rivers and Drainage Systems
Himalayan vs peninsular rivers, Ganga, Brahmaputra, Godavari, Narmada, lakes.
India  Rivers and Drainage Systems
Drainage — Rivers of India
What you'll learn
- Drainage — the system by which an area is drained by rivers.
- Drainage basin and watershed.
- Two major river systems: Himalayan rivers (perennial) vs Peninsular rivers (seasonal).
- Key rivers: Ganga, Brahmaputra, Indus, Narmada, Godavari, Krishna, Kaveri.
- Lakes in India and their importance.
Key concepts
Key terms
| Term | Meaning |
|---|---|
| Drainage basin | Area drained by a single river and its tributaries |
| Watershed | Ridge of high land dividing two drainage basins |
| Tributary | Smaller river joining a main river |
| Delta | Fan-shaped landform at river mouth (deposited silt) |
| Estuary | Funnel-shaped mouth where river meets sea (tidal) |
Himalayan rivers — perennial (year-round flow)
Fed by snowmelt + monsoon rain; erode actively; form meanders, oxbow lakes, deltas.
Ganga system
| River | Origin | Key facts |
|---|---|---|
| Ganga | Gangotri glacier (Uttarakhand) | 2525 km; most sacred; joins Bay of Bengal; forms world's largest delta (Sundarbans) with Brahmaputra |
| Yamuna | Yamunotri glacier | Longest tributary of Ganga; Delhi, Agra, Allahabad |
| Ghaghra / Kosi | Nepal Himalayas | Major left-bank tributaries; Kosi = "Sorrow of Bihar" (floods) |
| Son / Chambal / Betwa | Peninsular plateau | Right-bank tributaries |
Brahmaputra
- Longest river in India by volume; originates in Tibet as Tsangpo.
- Enters India through Arunachal Pradesh; flows west through Assam.
- Majuli (Assam) — world's largest river island.
- Joins Ganga in Bangladesh → Meghna → Bay of Bengal.
Indus
- Originates in Tibet near Mansarovar Lake; flows through Ladakh.
- Most of basin in Pakistan; India uses via Indus Waters Treaty (1960) with Pakistan.
Peninsular rivers — rain-fed (seasonal)
Older, shallower; mostly flow east into Bay of Bengal; form deltas. Western rivers (Narmada, Tapti) flow into Arabian Sea through estuaries.
| River | Length | Flows into | Key feature |
|---|---|---|---|
| Godavari | 1465 km | Bay of Bengal | Longest peninsular river; "Ganga of the South"; Andhra Pradesh |
| Krishna | 1400 km | Bay of Bengal | Maharashtra, Karnataka, AP |
| Kaveri | 800 km | Bay of Bengal | Karnataka + Tamil Nadu; Cauvery water dispute |
| Narmada | 1312 km | Arabian Sea | Flows through Vindhya–Satpura rift valley; Sardar Sarovar Dam |
| Tapti | 724 km | Arabian Sea | Parallel to Narmada; rift valley river |
| Mahanadi | 858 km | Bay of Bengal | Odisha; Hirakud Dam (longest earthen dam in India) |
Lakes
| Lake | State | Type | Feature |
|---|---|---|---|
| Wular | J&K | Tectonic | Largest freshwater lake in India |
| Dal | J&K | Tectonic | Famous houseboats; Kashmir tourism |
| Chilika | Odisha | Lagoon (saline) | Largest coastal lake in India; Ramsar wetland; flamingos |
| Sambhar | Rajasthan | Saline | Largest inland salt lake; source of salt |
| Loktak | Manipur | Freshwater | Floating phumdis (vegetation islands) |
| Vembanad | Kerala | Lagoon | Kerala backwaters; Nehru Trophy boat race |
Importance of rivers
- Water supply for drinking, irrigation, industry.
- Hydroelectric power (Bhakra Nangal, Hirakud, Sardar Sarovar).
- Navigation (Ganga, Brahmaputra).
- Fertile plains from alluvial deposit.
- Cultural significance — Ganga, Yamuna considered sacred.
River pollution — a concern
- Industrial effluents, sewage, religious rituals dump waste.
- Namami Gange programme (2014) — government initiative to clean Ganga.
Quick check
- What is the difference between a Himalayan and a Peninsular river?
- Name the origin of the Ganga. Which delta does it form?
- What is special about the Brahmaputra river?
- Name two west-flowing peninsular rivers. Why do they form estuaries, not deltas?
- Name the largest freshwater and largest saltwater lakes in India.
Open the Practice tab for graded questions on Drainage.
Key Takeaways (TL;DR)
- What you'll learn
- Key concepts
- Quick check
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