Lesson 68 of 94 7 min Free
Physical Features and Drainage of India
GS1 · Indian Geography
Location and size
- India lies wholly in the Northern Hemisphere. The Tropic of Cancer (23.5°N) passes through eight states.
- Area: about 3.287 million sq km – the 7th largest country, with about 2.4% of the world's land area.
- The Standard Meridian (82°30′E) passes near Mirzapur (Uttar Pradesh). IST is UTC +5:30.
Six physical divisions
| Division | Key facts |
|---|---|
| Himalayas | Young fold mountains; three parallel ranges: Himadri (Greater), Himachal (Lesser), Shiwalik (Outer) |
| Northern Plains | Alluvial plains of the Indus, Ganga and Brahmaputra; very fertile; bhabar, terai, bhangar (old alluvium) and khadar (new alluvium) |
| Peninsular Plateau | Oldest landmass (part of Gondwana); Deccan Plateau, Malwa, Chota Nagpur; Western and Eastern Ghats |
| Indian Desert | Thar, west of the Aravallis; low rainfall; sand dunes |
| Coastal Plains | Western coast (narrow: Konkan, Kanara, Malabar) and eastern coast (wide, with deltas) |
| Islands | Andaman & Nicobar (Bay of Bengal, volcanic/tectonic); Lakshadweep (Arabian Sea, coral) |
Rivers: two families
| Himalayan rivers | Peninsular rivers |
|---|---|
| Perennial (snow-fed + rain) | Mostly seasonal (rain-fed) |
| Long courses; deep gorges; meanders | Shorter, shallower valleys |
| Indus, Ganga, Brahmaputra | Mahanadi, Godavari, Krishna, Kaveri, Narmada, Tapi |
- The Godavari is the longest peninsular river ("Dakshin Ganga").
- The Narmada and Tapi flow west through rift valleys and form estuaries, not deltas.
- The east-flowing Mahanadi, Godavari, Krishna and Kaveri form deltas on the Bay of Bengal.
- The Ganga–Brahmaputra delta (Sundarbans) is the world's largest delta.
Indus Waters Treaty (1960)
India and Pakistan, with World Bank help. India gets the eastern rivers (Ravi, Beas, Sutlej). Pakistan gets the western rivers (Indus, Jhelum, Chenab), with some uses allowed to India.
Background: how India's landforms were made
About 200 million years ago, India was part of Gondwana. The Indian plate broke away, moved north, and collided with the Eurasian plate about 40–50 million years ago. That collision folded the sediments of the Tethys Sea into the Himalaya, which are still rising. The plains formed later from river sediments, while the Peninsula is an ancient, stable block of hard rocks. This one story explains earthquakes in the north, black soils on the Deccan lava and the great rivers.
The six physiographic divisions
| Division | Key facts |
|---|---|
| Himalaya | Three parallel ranges: Himadri (Greater, avg. ~6,000 m; Kanchenjunga is India's highest peak in the Himalaya), Himachal (Lesser – Pir Panjal, Dhauladhar, hill stations) and Shiwaliks (outer, with "duns" like Dehradun). Regional divisions: Punjab, Kumaon, Nepal and Assam Himalaya. Purvanchal hills in the north-east (Patkai, Naga, Mizo). Trans-Himalaya (Karakoram – K2/Godwin Austen, the highest peak in Indian territory as depicted in the official map – plus Ladakh and Zaskar). |
| Northern Plains | Formed by the Indus, Ganga and Brahmaputra systems. Sub-zones: bhabar (pebbles; streams disappear), terai (marshy, re-emerging streams), bhangar (older alluvium, kankar), khadar (new, fertile flood-plain alluvium). |
| Peninsular Plateau | Central Highlands (Malwa, Bundelkhand, Chota Nagpur) and the Deccan Plateau. Western Ghats (Sahyadri – continuous, higher; Anamudi 2,695 m is the highest peak in the Peninsula) and Eastern Ghats (broken by rivers). |
| Indian Desert | Thar, west of the Aravallis; sand dunes (barchans); Luni is the only large river. |
| Coastal Plains | Western (Konkan, Kanara, Malabar – narrow, with lagoons/kayals) and Eastern (Northern Circars, Coromandel – wider, with deltas). |
| Islands | Andaman and Nicobar (volcanic and tectonic, Barren Island – India's only active volcano) and Lakshadweep (coral atolls). |
Drainage systems – Himalayan vs Peninsular rivers
| Point | Himalayan rivers | Peninsular rivers |
|---|---|---|
| Source | Glaciers and snow | Rain-fed hills |
| Flow | Perennial | Seasonal |
| Valleys | Deep gorges (antecedent – older than the mountains) | Broad, shallow, mature valleys |
| Course | Meandering in plains; change course (the Kosi – "sorrow of Bihar") | Fixed courses, mostly |
| Mouth | Large deltas (the Sundarbans) | Deltas on the east coast; estuaries on the west (Narmada, Tapi) |
Key rivers:
- Indus – rises near Mansarovar; Jhelum, Chenab, Ravi, Beas and Sutlej join. The Indus Waters Treaty (1960) gave the eastern rivers to India and the western rivers mainly to Pakistan.
- Ganga – Bhagirathi + Alaknanda meet at Devprayag. Tributaries:
- from the left: Yamuna (joins at Prayagraj from the right bank), Ghaghara, Gandak, Kosi;
- from the right (peninsular side): Chambal, Betwa, Son.
- Brahmaputra – the Tsangpo in Tibet; enters India as the Siang/Dihang in Arunachal Pradesh; Majuli is a large river island; the Jamuna in Bangladesh.
- East-flowing peninsular rivers: Mahanadi, Godavari (the longest peninsular river – "Dakshin Ganga"), Krishna, Kaveri.
- West-flowing: Narmada and Tapi flow through rift valleys and form estuaries.
Causes and effects – why drainage matters for development
Effects of the Himalayan rivers: fertile plains (food bowl), hydropower potential, navigation (National Waterway 1 on the Ganga). They also cause floods, siltation and course changes (the Kosi, Brahmaputra).
Peninsular rivers: dams and canals for irrigation, but also inter-state water disputes (Kaveri, Krishna, Mahadayi), since water is scarce in the dry season.
River-linking (the Ken–Betwa project, the first approved) aims to transfer surplus water, but it raises ecological concerns (Panna Tiger Reserve) and displacement concerns.
Case study: the Kosi – "sorrow of Bihar"
The Kosi carries heavy silt from the Himalaya (Nepal) and has shifted its course westward by more than 100 km over about two centuries. In 2008, the embankment broke at Kusaha (Nepal), and the river took an old course, affecting millions in Bihar. The lesson: embankments alone cannot tame silt-heavy rivers. We need catchment treatment, early warning, flood-plain zoning and cooperation with Nepal.
Common misconceptions
- "The Ganga's source is Gangotri town." – It rises from the Gangotri glacier at Gaumukh. The name Ganga begins only after Devprayag.
- "All west-flowing rivers form estuaries because the west coast is rocky." – The main reasons are the rift-valley course, steep gradients, low silt load and strong tidal action.
- "The Aravallis are young mountains." – They are among the oldest fold mountains in the world (Proterozoic), heavily eroded.
How UPSC asks it
Prelims uses river–tributary pairs, peaks and passes, the order of rivers from north to south, and where rivers originate. Mains themes include comparing Himalayan and Peninsular drainage, river-linking, and why the Himalaya are prone to disasters.
Mains answer framework
Q-type: "Discuss the merits and demerits of the inter-linking of rivers in India."
- Introduction: the National Perspective Plan (1980) – Himalayan and Peninsular components; Ken–Betwa as a first project.
- Merits: irrigation, flood moderation, drought relief, hydropower, navigation.
- Demerits: ecology (forests, deltas, sediments), displacement, cost, inter-state and international disputes, climate uncertainty.
- Way forward: basin-level planning, local water harvesting, environmental flows, consensus.
- Conclusion: use it selectively, alongside decentralised solutions.
Himalayan and peninsular rivers compared
| Feature | Himalayan rivers | Peninsular rivers |
|---|---|---|
| Source | Glaciers and snowfields | Rain-fed, from plateaus and the Western Ghats |
| Flow | Perennial | Largely seasonal |
| Valleys | Deep gorges; antecedent drainage | Broad, shallow valleys; mature rivers |
| Delta / estuary | Large deltas (Ganga–Brahmaputra) | East-flowing rivers form deltas; west-flowing ones (Narmada, Tapi) form estuaries |
| Examples | Indus, Ganga, Brahmaputra | Godavari, Krishna, Kaveri, Mahanadi, Narmada, Tapi |
Practice question
Q. Why do the Narmada and Tapi form estuaries rather than deltas? They flow through rift valleys with hard rock, carry relatively less sediment, and enter the sea where tidal action carries sediment away.
Check your understanding
- Name the three parallel ranges of the Himalaya. The Greater Himalaya (Himadri), the Lesser Himalaya (Himachal) and the Outer Himalaya (Shiwaliks).
- What are the Western and Eastern Ghats? The Western Ghats are continuous and higher, causing orographic rain; the Eastern Ghats are discontinuous and cut by east-flowing rivers.
⚡ Quick revision
- 82°30′E Standard Meridian near Mirzapur; 7th largest; 2.4% of land
- Himadri–Himachal–Shiwalik
- Narmada and Tapi: west-flowing, rift valleys, estuaries
- Godavari = longest peninsular river
The Tropic of Cancer is the line of latitude at about 23.4° North, the northernmost point where the Sun can be directly overhead at noon, which it is on the June solstice; in India it passes through eight states and roughly divides the country into tropical and subtropical halves.The young fold-mountain system that arcs about 2,400 km along India's northern frontier from the Indus gorge to the Brahmaputra bend. This hub page links the range's role in climate, rivers, hazards, ecology and security; physiography in depth is in the linked lesson.India's largest river system, formed at Devprayag where the Bhagirathi (from Gaumukh at the Gangotri glacier) meets the Alaknanda, which flows about 2,500 km across the northern plains to the Bay of Bengal, ending in the world's largest delta shared with the Brahmaputra.A great trans-Himalayan river that rises near Lake Mansarovar in Tibet, flows east as the Yarlung Tsangpo, swings south around Namcha Barwa into Arunachal Pradesh as the Siang, crosses the Assam valley and joins the Ganga in Bangladesh.The large triangular tableland that forms most of peninsular India south of the Satpura and Vindhya ranges, bounded by the Western Ghats on the west and the Eastern Ghats on the east, tilting gently eastwards so that most of its rivers drain into the Bay of Bengal.A major east-flowing peninsular river, about 850 km long, that rises near Sihawa in Dhamtari district of Chhattisgarh, flows through the Chhattisgarh plain and Odisha, is dammed at Hirakud and builds a large delta near Cuttack before entering the Bay of Bengal.The longest river of peninsular India, about 1,465 km long, rising near Trimbakeshwar in Nashik district of Maharashtra and flowing east across the Deccan to enter the Bay of Bengal through a delta in Andhra Pradesh; it is often called the Dakshin Ganga.The World Bank is an international financial institution, created at the Bretton Woods Conference of 1944, that provides loans, grants and advice to developing countries for projects and reforms aimed at reducing poverty and promoting growth; it is part of the wider World Bank Group headquartered in Washington, D.C.A Himalayan river of the Indus system, about 470 km long, that rises at Beas Kund near the Rohtang Pass in Himachal Pradesh, flows through the Kullu valley and Mandi, is dammed at Pandoh and Pong, and joins the Sutlej at Harike in Punjab, flowing entirely within India.The easternmost and longest of the five rivers of the Punjab, an antecedent river that rises near Lake Rakshastal in Tibet, enters India at Shipki La in Himachal Pradesh, flows through Punjab and joins the Chenab in Pakistan to form the Panjnad before reaching the Indus.The Jhelum, known in ancient texts as the Vitasta, rises at Verinag in the south of the Kashmir valley, flows north-west through Srinagar and Wular Lake, cuts through the Pir Panjal at Baramulla into Pakistan-occupied territory and Pakistan, and joins the Chenab at Trimmu. It is one of the three western rivers allotted to Pakistan under the Indus Waters Treaty.Sudden shaking of the ground caused by the release of energy along faults. Full coverage: Earthquakes and Tsunamis.
Tap a feature for a short note.
India boundary as per Survey of India. Data: Natural Earth, OpenStreetMap, Wikidata, UNESCO. © UPSCPrep.in
