Physical Features of India: Mountains, Plains, Plateau, and Coasts

India’s map is easier to remember as six landform regions: the Himalayan mountains, the northern plains, the peninsular plateau, the Indian desert, the coastal plains, and the islands. Each region has its own rock, climate, and way of life.

This post explains how those regions formed and how to tell them apart. It follows location, size, and borders and leads into rivers, climate, and vegetation and soils.

How the land was built#

The peninsula is old. Its core was part of Gondwana, the southern supercontinent that also included Africa, Australia, and Antarctica. That block is stable. It has not folded into young mountain belts the way the Himalaya has.

The Himalaya is young. The Indian plate is still pushing north into Eurasia. The collision, underway for about 50 million years, crumpled the old sea floor of the Tethys Ocean into the highest mountains on Earth. Those peaks are still rising, and the same motion causes earthquakes across the mountain front.

Between the young mountains and the old plateau, rivers have laid down a deep blanket of silt. That blanket is the northern plain, one of the most farmed landscapes on the planet.

The Himalayan mountains#

The Himalaya runs in a broad arc from the Indus gorge in the northwest to the Brahmaputra gorge in the east. Three ranges sit side by side.

The Greater Himalaya, or Himadri, holds the highest peaks. Kangchenjunga, on the Sikkim–Nepal border, reaches 8,586 meters (28,169 feet) and is the highest peak in India. Nanda Devi, in Uttarakhand, is 7,816 meters (25,643 feet). Snow and glaciers in this belt feed the Indus, Ganga, and Brahmaputra.

The Lesser Himalaya, or Himachal, is a lower, rugged belt of valleys and hill towns. Srinagar, Shimla, Mussoorie, and Darjeeling sit in or beside this zone. The ranges are cut by deep river valleys.

The Siwalik, or outer Himalaya, is the lowest and youngest ridge. It is made of loose sand and gravel washed out of the higher mountains. South of it, a dry pebble belt called the bhabar soaks up small streams. Farther out, the terai is wet, marshy ground where that water returns to the surface.

East of the Brahmaputra, the mountains bend south. This is the Purvanchal: the Patkai, Naga, Manipur, and Mizo hills. They are lower than the Greater Himalaya but thickly forested, and they form India’s border with Myanmar.

Passes cut the wall. Zoji La links Srinagar and Ladakh. Shipki La is on the Himachal–Tibet route. Nathu La connects Sikkim with Tibet. These gaps have carried trade for centuries and still matter for roads and military posts.

The northern plains#

South of the Siwalik, the plains stretch from Punjab to Assam. The Indus, Ganga, and Brahmaputra systems built them with silt. In places the alluvium is hundreds of meters deep.

People divide the plain by river basin:

• The Punjab plains are drained by the Indus tributaries: the Jhelum, Chenab, Ravi, Beas, and Sutlej.
• The Ganga plain runs across Uttar Pradesh, Bihar, and West Bengal. It is the largest of the three.
• The Brahmaputra plain in Assam is narrower and floods often because the river is braided and the valley is framed by hills.

Farmers also distinguish older and newer silt. Bhangar is older alluvium, slightly above the present flood line, with clay patches called kankar. Khadar is newer silt on the active floodplain. It is refreshed almost every year and is very fertile.

The plain is flat, but it is not featureless. Levees, old river courses, and slight rises decide which fields flood. A shift of a few meters in height can decide a village’s crop.

The peninsular plateau#

The plateau is a triangle with its point near the southern tip of India. The Narmada river marks a useful split. North of it are the Central Highlands: the Malwa plateau, Bundelkhand, Baghelkhand, and the mineral-rich Chota Nagpur plateau. South of it is the Deccan plateau, tilted so that most large rivers flow east.

The western edge is the Western Ghats, also called the Sahyadri. They are a continuous escarpment. Orographic rain hits this wall first, so the seaward side is wet and the interior sits in a rain shadow. Anaimudi, in Kerala’s Anaimalai Hills, reaches 2,695 meters (8,842 feet), the highest peak in peninsular India.

The Eastern Ghats are broken into separate hills. Rivers cut through them to reach the Bay of Bengal. Mahendragiri, in Odisha, is among the better-known summits, at about 1,501 meters (4,925 feet).

The northwest corner of the old plateau holds the Aravalli Range, one of the oldest fold mountains still standing. It runs from Gujarat toward Delhi. Guru Shikhar, at 1,722 meters (5,650 feet), is its highest point. The range is worn down, but it still separates the Thar Desert from the wetter east.

Much of the northwestern Deccan is covered by the Deccan Traps, stacked lava flows from the end of the Cretaceous period. Those basalts weather into black soil, which is why cotton became the classic crop of Maharashtra and neighboring states. The soils post explains that link.

The Indian desert#

The Thar Desert lies west of the Aravalli, mostly in Rajasthan, with a fringe in Gujarat, Punjab, and Haryana. Rainfall in the far west often stays under 150 millimeters (6 inches) a year. Sand dunes, rocky hamada, and salt flats share the landscape.

The Luni is the main river. It rises in the Aravalli and disappears toward the Rann of Kutch. It is saline in its lower course and does not reach the sea as a steady freshwater stream.

The desert is not empty. Towns such as Jaisalmer and Bikaner grew on trade routes. The Indira Gandhi Canal brings Himalayan water into parts of northwest Rajasthan, which has changed cropping in a narrow irrigated belt. Away from canals, herding and drought-resistant crops still set the pace.

Coastal plains#

The western coastal plain is a narrow strip between the Western Ghats and the Arabian Sea. It includes the Gujarat coast, the Konkan (Maharashtra and Goa), the Kanara coast (Karnataka), and the Malabar coast (Kerala). Short, swift rivers drop out of the Ghats. Estuaries and Kerala’s backwaters are typical. There are few wide deltas, because the rivers are short and the shelf is steep.

The eastern coastal plain is wider. Large rivers—the Mahanadi, Godavari, Krishna, and Kaveri—have built deltas into the Bay of Bengal. The northern stretch is often called the Northern Circars. The southern stretch, in Tamil Nadu, is the Coromandel Coast. These deltas are major rice regions. They are also exposed to Bay of Bengal cyclones in the retreating-monsoon season.

Islands#

Lakshadweep, in the Arabian Sea, is a group of small coral atolls and reefs. The land area is tiny. Lagoons and reefs are the real geography. The highest ground is only a few meters above the sea, so storms and rising water are a direct threat.

The Andaman and Nicobar Islands form a long chain in the Bay of Bengal. Most are hilly and forested. Barren Island, in the Andamans, is India’s only active volcano. The islands sit near a plate boundary, which is why the 2004 Indian Ocean earthquake and tsunami hit them so hard. Indira Point, on Great Nicobar, is India’s southernmost point.

How to keep the six regions straight#

Use one test for each region:

• Himalaya: young, high, still rising, snow-fed rivers.
• Northern plain: deep river silt, very flat, densely farmed.
• Plateau: old hard rock, tilted east, edged by ghats.
• Desert: west of the Aravalli, dunes and the Luni.
• Coasts: narrow and wet in the west, wide and deltaic in the east.
• Islands: coral in the Arabian Sea, forested volcanic-arc hills in the Bay of Bengal.

A sketch with those six labels is enough for most world-geography questions. Add the Narmada as the line between the Central Highlands and the Deccan, and add the Western Ghats as the rain wall.

If you are building a class handout, put a labeled sketch on one page and a blank sketch on the next. Combine them with Merge PDF so students get one file. Mark the blank page in a browser with Edit PDF.

FAQ#

What is the highest mountain in India?#

Kangchenjunga, at 8,586 meters on the border of Sikkim and Nepal, is the highest peak in India. K2 is higher but stands in the Karakoram under Pakistani administration, in territory India also claims.

Why do most peninsular rivers flow east?#

The Deccan plateau is higher in the west. The Western Ghats form that high edge, so water runs down the gentler eastern slope to the Bay of Bengal. The Narmada and Tapi are exceptions. They follow rift valleys west to the Arabian Sea.

Are the Himalaya still growing?#

Yes. The Indian plate is still pushing into Eurasia. Uplift is slow in human terms, but earthquakes along the mountain front show that the collision is active.

Where to go next#

Landforms decide where water can go. The next post follows India’s rivers and lakes, from the snow-fed Himalayan systems to the seasonal rivers of the peninsula.