Geography of India: Physiographic Divisions

Study Notes

The Himalayas are young fold mountains that extend from the Pamir Knot in Tajikistan to the East
In India, they extend from Jammu and Kashmir to Arunachal Pradesh
The Himalayas are not a single mountain range, but multiple parallel ranges including:
Siwaliks (the southernmost and youngest)
Lesser Himalayas
Greater Himalayas (Himadri)
Trans Himalayan ranges
The mountain ranges are also divided into:
Western Himalayas (or Kashmir Himalayas)
Central Himalayas (or Kumaun Himalayas)
Eastern Himalayas (or Assam Himalayas)

The North Indian Plains lie between the Himalaya Mountains in the north and the Peninsula in the south
They extend from Rajasthan and Punjab in the west to Assam in the east
The plain is mostly a flat, low-lying area
It is divided into two parts:
The part lying to the east of the Aravalis is the basin of the river Ganga and is known as the Ganga Plains
It slopes eastward and includes the delta of Ganga-Brahmaputra system, known as Sunderbans, which is the world’s largest delta

The area lying to the south of North Indian plains and tapering towards the Indian Ocean is called the Indian Peninsula
It consists of many plateaus and hill ranges
The Aravalis in the north are the oldest fold mountains in the region
It includes a series of plateaus bordering the plains, Vindhyas and Satpura ranges in the central part, and the hilly regions of Western and Eastern Ghats

The Coastal Plains lie to the western side of the Peninsula
It is a long coastline extending for 7500 km
The western coastline shows remarkable dissection
The western coast borders the Arabian Sea and is a rocky coast
Spurs taking off from the Western Ghats are extended right up to the coast
Rivers originating from the Western Ghats are short and swift, so their mouths are less defined and are not deltas
The eastern coast borders West Bengal and has formed as a result of the work of rivers
Many east-flowing rivers from the Western and Eastern Ghats coast flow at lower velocities, and sediments brought with them at the lower end result in deltas found along this coast

India has many small and large islands along the mainland
These are included in the Indian Island group
Besides, India has two groups of islands, one each in the Arabian Sea and Bay of Bengal
The islands in the Arabian Sea are known as Lakshadweep, and those in the Bay of Bengal are called the Andaman and Nicobar Islands
Most of the islands in Lakshadweep are coral islands of atoll shape and small in extent

The southern Brazil is occupied by an extensive plateau, known as the Brazilian Highlands or Brazilian Shield or Brazilian Plateau
It covers the states of Roraima, Para, and Amapa in the north
The lower part of these highlands is found in Brazil, with an altitude of more than 1000m
The highest peak of Brazil, Pico de Neblina, is 3014m high and lies on the border between Brazil and Venezuela

Occurs in a small area but greatly impacts the climate
Its height is 790m
Steep from Sao Paulo to Porto Alegre
Acts as a barrier to Southeast Trade Winds, creating a rain shadow area in the northeast

Brazil has a coastline of 7400 km
Divided into Northern and Eastern Coasts
The Northern Coast extends from Amapa to Rio Grande do Norte, also known as the North Atlantic Coast
The Eastern Coast extends from the North towards the South
The Northern Coast is characterized by river mouths, including the Amazon, making it a low-lying region
The Eastern Coast receives many smaller rivers, with the only major river being the Amazon

Confined to two areas: the Amazon Basin in the north and Paraguay-Parana source region in the southwest
The Amazon Plains form the largest plain in Brazil, sloping eastwards
The Paraguay-Parana source region is located in southwestern Brazil
The source region of Paraguay slopes south, and the source region of Parana slopes southwest

Divided into Coastal and Marine Islands
Coastal islands are formed by deposition, while Marine islands were part of the mainland
Marine Islands are 300km away from the mainland, are mostly rocky, and are the tops of submerged mountains
Coral islands near the coast are called atolls