Major physiographic divisions of India: ( This is the second part of the previous post
2. The Northern Plain
- It is formed by three river systems namely – Indus, Ganga and Brahmaputra.
- It spreads over an area of 7 lakh sq. km.
- It is formed of alluvial soil.
- It is 2,400 km long and 240-320 km broad.
- The western part of the Northern plains is known as Punjab plains, which is formed by Indus and its tributaries.
- The Ganga plain extends between Ghaggar and Teesta rivers.
- The rivers, after descending from the mountains deposit pebbles in a narrow belt of about 8 to 16 km in width lying parallel to the slopes of the Shiwaliks. It is known as bhabar.
- All the streams disappear in the bhabar belt.
- South of this belt, the streams and rivers re-emerge and create a wet, swampy and marshy region known as terai.
- The part of Northern plains, which lies above the flood plains and is formed of older alluvium, is known as bhangar.
- The soil in this region contains calcareous deposits locally known as kankar.
- The newer and younger deposits of the flood plains are known as khadar.
3. The Peninsular Plateau:
- It is composed of old crystalline, igneous and metamorphic rocks.
- It is divided into two parts: Central Highlands and Deccan Plateau.
- The part of Peninsular plateau lying to the north of Narmada river covering a major area of the Malwa plateau is known as the Central Highlands.
- The eastward extensions of Central Highlands are locally known as Bundelkhand and Baghelkhand.
- The extension of Deccan plateau in the northeast is known as Meghalaya and Karbi-Anglong plateau.
- The Western Ghats and Eastern Ghats mark the western and eastern edges of the Deccan plateau respectively.
- The average elevation of Western Ghats is 900-1600 metres while that of Eastern Ghats is 600 metres.
- The highest peaks in Western Ghats include Anai Mudi (2,695 metres) and Doda Betta (2,637 metres) and the highest peak in Eastern Ghats is Mahendragiri (1,501 metres).
- The Western Ghats cause orographic rainfall by facing the rain bearing moist winds to rise along the western slopes of the Ghats.
- Deccan Trap is the black soil area of volcanic origin.
4. The Indian Desert:
- It lies towards the western margins of the Aravali hills.
- It receives below 150 mm rainfall per year.
- Luni is the only large river that flows through it.
- The area is mostly covered by crescent shaped dunes known as barchans.
5. The Coastal Plains:
- The western coast consists of three sections, namely – Konkan coast, Kannad plain and Malabar coast.
- The northern part of the eastern coast is known as Northern Circar, while the southern part is known as Coromandal Coast.
- Lake Chilika is an important feature of the eastern coastal plains.
6. The Islands:
- Lakshadweep group of islands lie close to the Malabar coast of Kerala. These group of islands were earlier known as Laccadive, Minicoy and Amindive and were named Lakshadweep in 1973.
- It covers the area of 32 sq. km.
- The Pitli island has a bird sanctuary.
- The island group lying in the Bay of Bengal is known as Andaman and Nicobar islands.
- These islands experience equatorial climate as they lie close to the equator.