Physical Divisions of the Indian Subcontinent

Physical Divisions of the Indian Subcontinent

» A chain of high mountains radiate out from the Pamir Knot which lies just in the north of India
» In these mountains the Hindukush, the Sulaiman and the Kirthar in the east and the Himalayas in the west separate the Indian subcontinent from rest of Asia.
» Indian subcontinent can be divided into following physical divisions :
    ★ The Great Mountain Wall of the North
    ★ The Great Northern Plains
    ★ The Great Peninsular Plateau
    ★ The Coastal Plains
    ★ The Great Indian Desert
    ★ The Island Groups

The Great Mountain wall of the North

» The Himalayas, the highest mountain wall of the world, are situated on the northern boundary of India like an arc.
» From west to east the Himalayas are 2500 km long. The average breadth of the Himalayas is between 250 to 400 km.
» Mount Everest, the highest peak in the world, lies in these mountains in Nepal.
» The Himalayas consist of three parallel mountain ranges : (i) The Greater Himalayas, (ii) The Lesser Himalayas and (iii) The Outer Himalayas.

The Great Northern plains

» The northern plains are divided into three sub-divisions. These are the Punjab and Haryana plains. The Ganga plains and the Brahamaputra valley.
» The Ganga plains form the largest lowland drained by the Ganga and its tributaries.
» The Yamuna is the most important tributary of the Ganga.
» The Ghaghara, the Gandak, the Kosi and the Tista are other tributaries of the Ganga.
» The Sone and the Damodar are tributaries of the Ganga while the Chambal and the Betwa are tributaries of the Yamuna from the peninsular plateau.
» The Ganga plain has an extremely gentle slope. Parts of the plain are subject to floods in the rainy season. In the lower course, the Ganga divides itself into tributaries to form a large delta along with the Brahmaputra.
» The Punjab and Haryana plains represent a part of the Indus basin.
» A low watershed separates these plains from the Ganga plains.

The Great Pensinsular Plateau

» Anamudi or Anaimudi (2,695 m) situated in Sahyadri range is the highest peak of the peninsula.
» The Deccan plateau includes the area to the south of the Vindhyas.
» The western edge of the plateau rises steeply from the Arabian Sea to form the Western Ghats (which includes the Sahyadri).
» The Deccan plateau slopes gently towards the east. The surface of the plateau is dissected into a rolling upland by a number of rivers.
» The elevation ranges from 300 to 900 metres.
» The eastern edge of the plateau is known as the Eastern Ghats.
» The north-western region of the Deccan plateau is covered by nearly horizontal sheets of lava. This region is called 'Deccan trap region.' The Deccan plateau is drained by many long east flowing rivers. These rivers originate in the Western Ghats, flow towards the east and enter the Bay of Bengal.
» The Godavari, the Mahanadi, the Krishna and the Cauvery are the major rivers that have built deltas along the coast.
» The Narmada and the Tapti rivers are west flowing.
» Both the rivers enter the Arabian Sea along the Gujarat coast.
» These rivers do not have deltas.
Major Plateaus :
Marwar Upland, Central Highland, Bundelkhand, Malwa Plateau, Baghelkhand, Chhotanagpur Plateau (Hazaribagh Plateau, Ranchi Plateau and Raj Mahal Hills), Meghalaya Plateau, Deccan Plateau, Maharashtra Plateau, Karnataka Plateau, Telangana Plateau, Chhattisgarh Plain.

The Coastal Plains

Narrow strips of flat land on eastern and western coasts are known as the East Coastal Plain and the West Coastal Plain respectively.

The West Coastal Plain
» This plain which lies between the Arabian Sea and the Western Ghats spreads from Gujarat in the north to Kanyakumari in the south.
» It is broader in the north and narrower in the south. This uneven plain has been dissected by many fast flowing rivers.
» Its northen part from Gujarat to Goa is called Konkan, while southern part from Goa to Kanyakumari is known as Malabar. Several lagoons (salt water lakes separated from the main sea by sand bars and spits) are found on the coastal plain.
» Important ports developed on its coast from north to south are : Kandla, Mumbai, New Jawahar Port Mumbai, Marmagao, Mangalore and Cochin.

The East Coastal Plain
» This broader coastal plain spreads along the Bay of Bengal from Odisha in the north to Kaynakumari in the south.
» Its northern part is known as Northern Circar plains and the southern part is called Coromandal Coast Rivers like Mahanadi, Godavari, Krishna and Cauvery form deltas on this plain.
» This coast is famous for rice cultivation.
» A large number of lagoons are also found here.
» Chilka and Pulicat lakes are fine examples of lagoons on our east coast.

The Great Indian Desert

» It lies to the west of the Aravali range.
» It extends over major part of Rajasthan and Sindh in Pakistan.
» This desert does not get much rain as the Aravali range run parallel to the south-western monsoon winds.
» It is in the rain shadow area of the Bay of Bengal current.
» Lake Sambhar is found here.

The Island Groups

» Lakshadweep is a group of 36 coral islands in the Arabian Sea.
» It is located 300 km to the west of the coast of Kerala.
» Andaman and Nicobar islands are a group of about 324 islands.
» Most of these islands are uninhabited.
» Andaman and Nicobar islands are separated by the Ten Degree Channel because 10°N latitude passes through this place.

Climatic Diversity in the Indian Subcontinent

» Due to the vastness of the country and a variety of relief features there are regional variations in the climate of India.
» The interior of the country, specially in the north, has a continental type of climate.
» The coastal areas have a more equable climate. In mountainous areas, altitude determines the climate. There is a great deal of variation in the amount of annual rainfall.
» In June, the highest temperature in Rajasthan may go up to 55°C. But, in Drass and Kargil the night temperature in January may go down to -45°C to -50°C. Mawsynram and Cherrapunji in Meghalaya have an annual rainfall of 873 mm (467 in) and 11,430 mm (450 in) respectively. But, in the Thar Desert the annual rainfall is less than 500 mm (20 in)
» Along the Malabar Coast (Kerala) the annual range of temperature is about 3°C. But, it is 20°C in Hissar, Ambala and other parts of the interior.