Physical Features of India
India is a vast country with diverse landforms including mountains, plains, deserts, plateaus, and islands.
Geologically, the Peninsular Plateau is one of the most ancient landmasses on Earth, considered a stable block.
The Himalayas and the Northern Plains are the most recent landforms in India.
From a geological perspective, the Himalayan mountains form an unstable zone with youthful topography, high peaks, deep valleys, and fast-flowing rivers.
The Northern Plains are formed by alluvial deposits.
The Peninsular Plateau is composed of igneous and metamorphic rocks, featuring gently rising hills and wide valleys.
The major physiographic divisions of India are the Himalayan Mountains, the Northern Plains, the Peninsular Plateau, the Indian Desert, the Coastal Plains, and the Islands.
The Himalayas are geologically young and structurally fold mountains stretching along India's northern border from the Indus to the Brahmaputra.
The Himalayas form an arc covering about 2,400 km, with widths varying from 400 km in Kashmir to 150 km in Arunachal Pradesh.
The Himalaya consists of three parallel ranges: the Great or Inner Himalayas (Himadri), the Lesser Himalaya (Himachal), and the Shiwaliks.
The Himadri, the northernmost range, is the most continuous with an average height of 6,000 meters and contains all prominent Himalayan peaks like Mt. Everest and Kanchenjunga.
The core of the Great Himalayas is composed of granite and is perennially snow-bound with many descending glaciers.
The Himachal or Lesser Himalaya lies south of the Himadri, composed of highly compressed and altered rocks, with altitudes between 3,700 and 4,500 meters.
Prominent ranges in the Himachal include the Pir Panjal, Dhaula Dhar, and Mahabharat ranges.
The Kashmir Valley, Kangra, and Kullu Valleys are famous hill stations located in the Himachal range.
The Shiwaliks are the outermost range of the Himalayas, with a width of 10-50 km and altitude varying between 900 and 1,100 meters.
Shiwalik ranges are composed of unconsolidated sediments brought down by rivers from the main Himalayan ranges.
The longitudinal valleys lying between the Lesser Himalaya and the Shiwaliks are known as Duns, such as Dehra Dun, Kotli Dun, and Patli Dun.
Regional divisions of the Himalayas include the Punjab Himalayas (between Indus and Satluj), Kumaon Himalayas (between Satluj and Kali), Nepal Himalayas (between Kali and Teesta), and Assam Himalayas (between Teesta and Dihang).
The Brahmaputra River marks the easternmost boundary of the Himalayas; beyond the Dihang gorge, the Himalayas bend sharply south, forming the Purvachal or Eastern hills.
The Purvachal hills, running through the northeastern states, are mostly composed of strong sandstones (sedimentary rocks) and include the Patkai hills, Naga hills, Manipur hills, and Mizo hills.
The Northern Plain is formed by the interplay of the Indus, Ganga, and Brahmaputra river systems and their tributaries.
This fertile plain, formed by alluvial soil deposition, spreads over an area of 7 lakh sq. km, is about 2,400 km long and 240 to 320 km broad.
Due to its rich soil, adequate water, and favorable climate, the Northern Plain is agriculturally productive and densely populated.
Majuli, in the Brahmaputra River, is the world's largest inhabited riverine island.
Rivers in their lower course split into numerous channels called distributaries due to silt deposition.
The Northern Plain is divided into the Punjab Plains (formed by Indus and its tributaries), the Ganga Plain (between Ghaggar and Teesta rivers), and the Brahmaputra Plain (in Assam).
The Punjab Plains are formed by the Indus and its tributaries: Jhelum, Chenab, Ravi, Beas, and Satluj.
"Doab" means the land between two rivers, and "Punjab" means the land of five rivers.
The Ganga Plain extends across Haryana, Delhi, U.P., Bihar, partly Jharkhand, and West Bengal.
The Northern Plains can be divided into four regions based on relief variations: Bhabar, Terai, Bhangar, and Khadar.
The **Bhabar** is a narrow belt (8-16 km wide) parallel to the Shiwaliks where rivers deposit pebbles and streams disappear.
South of the Bhabar, streams re-emerge to create a wet, swampy, and marshy region known as the **Terai**, historically a thickly forested area.
The largest part of the Northern Plain is formed of older alluvium, known as **Bhangar**, which lies above the floodplains and has calcareous deposits called kankar.
The newer, younger deposits of the floodplains are called **Khadar**, renewed almost every year, making them fertile and ideal for intensive agriculture.
The Peninsular Plateau is a tableland composed of old crystalline, igneous, and metamorphic rocks, formed from the breaking and drifting of Gondwana land.
The plateau features broad and shallow valleys and rounded hills, divided into the Central Highlands and the Deccan Plateau.
The **Central Highlands** lie north of the Narmada River, covering a major area of the Malwa plateau, bounded by the Vindhyan range (south) and Aravalis (northwest).
The rivers in the Central Highlands (Chambal, Sind, Betwa, Ken) flow from southwest to northeast, indicating the plateau's slope.
The Central Highlands are wider in the west and narrower in the east, with eastward extensions known as Bundelkhand and Baghelkhand, and further east, the Chotanagpur plateau (drained by Damodar river).
The **Deccan Plateau** is a triangular landmass south of the Narmada River, flanked by the Satpura range (north) and eastern extensions like Mahadev, Kaimur hills, and Maikal range.
The Deccan Plateau is higher in the west and slopes gently eastwards; its northeastern extension includes the Meghalaya, Karbi-Anglong Plateau, and North Cachar Hills, separated by a fault from Chotanagpur.
Prominent hill ranges from west to east in the northeastern extension of the Deccan Plateau are the Garo, Khasi, and Jaintia Hills.
The Western Ghats and Eastern Ghats mark the western and eastern edges of the Deccan Plateau, respectively.
The **Western Ghats** lie parallel to the western coast, are continuous, and higher (900-1600 meters average elevation) than the Eastern Ghats.
The highest peaks in the Western Ghats include Anai Mudi (2,695 meters) and Doda Betta (2,637 meters).
The **Eastern Ghats** stretch from the Mahanadi Valley to the Nigiris, are discontinuous, irregular, and dissected by rivers draining into the Bay of Bengal, with an average elevation of 600 meters.
Mahendragiri (1,501 meters) is the highest peak in the Eastern Ghats.
Shevroy Hills and Javadi Hills are located southeast of the Eastern Ghats.
A distinct feature of the Peninsular Plateau is the **Deccan Trap**, a black soil area of volcanic origin, where denuded igneous rocks are responsible for black soil formation.
The **Aravali Hills** lie on the western and northwestern margins of the Peninsular Plateau, are highly eroded, and extend from Gujarat to Delhi in a southwest-northeast direction.
The **Indian Desert** (Thar Desert) lies towards the western margins of the Aravali Hills, an undulating sandy plain with sand dunes, receiving very low rainfall (below 150 mm per year).
The Indian Desert has an arid climate with low vegetation cover; streams appear during the rainy season but disappear into the sand due to insufficient water to reach the sea.
Luni is the only large river in the Indian Desert.
Barchans (crescent-shaped dunes) cover larger areas in the Indian Desert, with longitudinal dunes being more prominent near the Indo-Pakistan boundary.
The **Coastal Plains** flank the Peninsular Plateau, running along the Arabian Sea (west) and the Bay of Bengal (east).
The **Western Coastal Plain** is narrow, sandwiched between the Western Ghats and the Arabian Sea, divided into the Konkan (Mumbai-Goa), Kannad Plain (central), and Malabar Coast (southern).
The **plains along the Bay of Bengal** are wide and level, referred to as the Northern Circar (northern part) and the Coromandel Coast (southern part).
Large rivers like the Mahanadi, Godavari, Krishna, and Kaveri have formed extensive deltas on the Eastern Coastal Plain.
Lake Chilika, the largest saltwater lake in India, is an important feature along the eastern coast, located in Odisha, south of the Mahanadi delta.
India has two main island groups: the Lakshadweep Islands and the Andaman and Nicobar Islands.
The **Lakshadweep Islands** are a group of small coral islands close to the Malabar coast of Kerala, covering 32 sq km.
Formerly known as Laccadive, Minicoy, and Amindive, these islands were named Lakshadweep in 1973.
Kavaratti island is the administrative headquarters of Lakshadweep, which has great diversity of flora and fauna, including the Pitti island bird sanctuary.
Coral polyps are short-lived microscopic organisms that form colonies, flourishing in shallow, mud-free, warm waters, secreting calcium carbonate to form reefs (barrier, fringing, and atolls).
The **Andaman and Nicobar Islands** are an elongated chain of islands in the Bay of Bengal, divided into the Andaman (north) and Nicobar (south).
These islands are believed to be an elevated portion of submarine mountains and are strategically important for India.
The Andaman and Nicobar Islands have a great diversity of flora and fauna, lie close to the equator, experience an equatorial climate, and have thick forest cover.
India's only active volcano is found on Barren Island in the Andaman and Nicobar group of Islands.
Each physiographic unit of India complements the others, enriching the country's natural resources.
Mountains are major sources of water and forest wealth.
Northern Plains are the granaries of the country, providing the base for early civilizations.
The plateau is a storehouse of minerals, crucial for industrialization.
Coastal regions and island groups provide sites for fishing and port activities.
The diverse physical features of India offer immense future possibilities for development.