Physical Division of India
India is a vast region that has a great variety of different geological structures. It is, however, possible to divide the region into five physiographic regions, namely –
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About 120 million years ago, the arrangement of continents and Oceans was quite different. There used to be a shallow area, known as the Tethys Sea, lying between the Angara land in the north and Gondwanaland in the south. Literary meaning of the Himalayas is ‘abode of snow’. Considered to be the youngest mountain range of India, the Great Himalayas was born during Gandwana period some 50 millions years a go. The mountain born out of collision of two tectonic plates is called fold-mountains and the Himalayas is such a mountain.
Division of the Himalaya
The Himalaya consists of a series of parallel mountain ranges stretching in a northwest to southeast direction. The total length of the Himalayan is about 2415 km. The Himalayas are the highest mountain range in the world. It is divided into three divisions, namely
- The Northwest Himalayan Range
- The Northern Himalayan Range
- The Northeast Himalayan Range
The Northwest Range
A series of mountain ranges radiate from Pamir Knot – Hindukush toward south westward, Kunlun towards the east and Karakoram towards the south – east with Ladakh and Zaskar as parallel ranges from the great northern wall. The northern western ranges are almost dry, devoid of any vegetation. They have three prominent passes associated with three small rivers – The Kabul, The Gomal and The Bolan.
The Northern Range
The great Northern Range run in the form of a convex arc from Kashmir in the west to Assam in the east. It is a very high range and has the distinction of having the highest peaks of the world. The Great Himalayan Range extends from west to east over 2400 km. It’s comprises three distinct, parallel ranges.
- The Himadri or The Great Himalaya – Overlooking the Tibetan Plateau (5000 to 6000 m above sea level), it is also called Inner Himalayan
- The Middle or The Lesser Himalayan – also called Himachal at an elevation of about 3000 m;
- The Shiwalik Range or The Outer Himalayan – whose height varies between 1000 to 1500 m above sea level.
The North East Himalayan Ranges
On India’s northeast side are located the Purvanchal Mountain (the Eastern Hills). These hills running through Arunachal Pradesh, Na- galand, Manipur, Mizoram, Tripura and eastern Assam are series of hills mostly composed of sedimentary rocks with steeper western slopes and are highly dissected and slightly accurate (bent like a bow) with convex side facing west.
The Great Plain of India
To the south of the Himalaya and to the north of the peninsula lies the Great Plain of North India. It is a gradational plain formed by the depositional work of three major river systems viz the Indus, Ganga and the Brahmaputra. The Great Plain of North is the largest alluvial tract of the world extending nearly 3200 km and having average width that varies from 150-300 km. It covers a total area of about 7.8 lakh sq km. The northern boundary of the plain is well-defined by the foothills of the Shiwaliks. Average elevation of this plain vary upto 200 m above sea level.]
Regional Division of the Great Plain of India
- The Rajasthan Plain
- The Indus Punjab-Haryana Plain
- The Ganga Plain
- The Brahmaputra Plain
The Rajasthan Plain
The Rajasthan Plain extensively is sandy desert in the northern India and eastern Pakistan. This Plain is also called the Thar or The Great Indian Desert. Thar Desert is bounded on the northwest by the Sutlej river, on the east by the Aravalli Range, on the south by the Rann of Kutch and by the Indus Valley on the west.
It covers an area of about 800km in length and about 490 km in width. The total area of this plain is above 3.35 lakh sq km. The average elevation of the plain is about 457 m in the Aravalli and 61 m in the Rann of Kutch, above sea level. A number of short seasonal streams originate from the Aravalli.
The Indus Plain
The Great Indian Desert imperceptibly gives way to the fertile plain of the Punjab and Haryana towards the east and north-east. Extending to a length of 640 km in north-west to south-east direction and about 300 km wide in east-west direction the total area of this plain is above 1.75 lakh sq km, the region is drained by the river Indus and its tributaries viz the Sutlej, the Beas, the Ravi, the Chenab and the Jhelum. The northern part of this plain adjoining the shiwaliks hills. The area between the Ghaggar and the Yammuna rivers lies in Haryana and is often termed as ‘Haryana Tract’.
The Ganga Plain
This is the largest unit of the great plain of India stretching from Delhi to Kolkata in the of Uttar Pradesh, Bihar and West Bengal covering an area of about 3.75 lakh sq km. This plain has been named after the river Ganga. The Ganga along with its large number of tributaries originating in the Himalayan ranges viz, the Yammuna, the Gomti, the Ghaghara, the Gandak, the Kosi, etc., create a tract of river basins those are very fertile. The Peninsular river such as Chambal, Betwa, Ken, Son, etc., merge into the Ganga river system contributing to the formation of this plain.
The Brahmaputra Plain
Also known as the Brahmaputra Valley or Assam Valley or Assam Plain is often treated as the eastern continuation of the great Plain of India. It extends from the Eastern Himalays of Arunachal Pradesh in the norh, Patkai and Naga Hills in the east and the Garo-Khasi-Jaintia and Mikir Hills in the South. Its western boundary is formed by the Indo-Bangladesh border as well as the boundary of the lower Ganga plain. The entire plain covers an area of about 56 thousands sq km.
The Peninsular Plateau
Plateau is a high raised flat terrain and is otherwise known as table land or high land. The Peninsular Plateau of India extends from edge of Great Plain of India in the north and the Kanniyakumari in the south. In the west it extends from Kuchchh along the western bank of the Aravalli Range to near Delhi in the Ganga delta. It is surrounded by the hill ranges on all three sides. To its north are the Aravalli range, the Vindhya, the Satpura, Barmr and the Rajamahal Hills.
To the south of about 22 degree North latitude, the Western Ghats and the Eastern Ghats from its western and eastern boundary respectively. The entire plateau measures about 1600 km in north-south and 1400 km in east-west direction. It covers a total area of about 16 lakh sq km which is about half of the total land area of the country. It is thus, the largest physiological unit of India.
|Division of the Peninsular Plateau||Hill Ranges of the Paninsula|
|➢The Marwar Upland |
➢ The Central Highland
➢ The Bundelkhand Upland
➢ The Malwa Plateau
➢ The Bangelkhand
➢ The Chotanagpur Plateau
➢ The Meghalaya Plateau
➢ The Deccan plateau
|➢ The Aravali Range|
➢ The Vindhya Range
➢ The Satpura range
➢ The Western Ghats
➢ The Eastern Ghats
The Coastal Plains
The narrow coastal strip between the edge of the peninsular plateau and the coastline of India running for a distance of about 6000 km from the Ran of Kutch in the west to the Ganga-Brahmaputra delta in the east is called the coastal plain. The area between the Western Ghats and Arabian Sea Coast is known as the West Coastal Plain and the between the Eastern Ghats and the Coast of the Bay of Bengal is called the East Coastal Plains.
The two coastal plain meet each other at the southernmost tip Kanniyakumari. The west coastal Plain is further divided into The Kachchhh Peninsula, The Kathiawar Peninsula, The Gujarat Plain, The Konkan Plain, The Karnatka Coastal Plain and The Kerala Plain. The East Coastal Plain is divided into three namely, The Utkal Plain, The Andhra Plain and The Tamil Nadu Plain.
Perennial Himalayan Rivers
The rivers flowing from the great Himalayas are both rain fed and glacial fed. As during rainy season they carry rain water and during summers, the ice melt and such waters flow in these rivers. For this the rivers flowing for the Himalaya are perennial. Though there are several river systems flowing from the Himalayas, the below mentioned three are most important.
The Indus System
One of the largest river basin in the world the Indus river system comprises of five main tributaries namely the Jhelum, the Chenab, the Ravi, the Beas and the Sutlej. The Indus originates in the Tibet near Mansarovar lake. From the origin it flows north-westward it enters India near Damchok in Jammu and Kashmir. After flowing through Ladakh, Baltistan and Gilgit it enters Pakistan near Chilas in the Dardistan region.
The Ganga System
Popularly known as the Ganga, the river is the longest in the country. Sacred to the Hindus, the river originates in the name of Bhagirathi from the Himalayas, at Gaumakh. However the name Ganga follows only after the confluence of river Bhagirathi and Alaknanda at Devaprayag, a small town 74 kilometers from Rishikesh in the Garhwal Himalaya.
Though the river has so many streams joining the flow, there are six popular main streams namely Alaknanda, Dhauliganga, Nandakini, Pindar, Mandakini and Bhagirathi and five of their confluence namely Panch Prayag in order Bishnu Prayag (Dhauliganga merges into Alaknanda), Nanda Prayag (Nandakini joins Alaknanda), Karnaprayag (Pindar joins Alaknanda), Rudraprayag (Mandakini joins Alaknanda) and Devaprayag (confluence of Bhagirathi and Alaknanda) are popular and considered to be sacred in India.
The river Ganga is 2510 kilometer long and flows through China, India, Nepal and Bangladesh. The basin of the river Ganga is one of the most fertile and densely populated region in the world covering an area of 400 000 sq miles (1 000 000 sq km). Other main tributaries to the river Ganga are Yamuna, Son, Gomati, Ghaghara, Gandak, Kosi and Brahmaputra.
The river Yamuna the western most prominent tributary of the Ganga originates in the Yamunotri glacier, and travels more than 750 kilometers before it merges into the Ganga at Allahabad. Tributaries like Chambal, Betwa, and Ken flow northward to merge into river Yamuna before the river Yamuna itself merges into the Ganga.
The Brahmaputra River flows 2,900 km from its source in the Kailas range near Mansarovar lake around same region from where the Indus originates in the Trans-Himalayan region. From the origin it traverses eastward in the Tibetan region of China and enters India west of Sadiya town in Arunachal Pradesh. The river finally enters Bangladesh near Dubari and then flowing southwards it merges into Padma river which discharges in the Bay of Bengal. The flows through China, India, and Bangladesh, but its watershed includes Nepal, Bhutan and Myanmar as well.
The Peninsular Rivers
The peninsular rivers are considered to be older than the Himalayan river system. A large numbers of rivers here are non-perennial and dependent on the rainfall. The main river basins of the peninsula are the Mahanadi, Godavari, Krishna, Kaveri those discharge their waters in the Bay of Bengal. Rivers flowing westward are small and do not form delta. Most important amongst them are Narmada and Tapti.
The river Narmada’s originates from the mountains ‘Maikal’ in Madhya Pradesh. It rises on the summit of Amarkantak Hill in the Madhya Pradesh state and pursues a direct westerly course to the Gulf of Khambhat. It falls into the sea in the Bharuch district of Gujarat. Similarly the river Tapti rises in the Eastern Satpura range in Madhya Pradesh and going westward it drains into the Arbean Sea.
The river Kaveri flows through the states of Karnataka and Tamil Nadu after orginating from the Brahmagiri Mountains in Mysore at a height of 1320 metres above sea level. This river runs through some of the most fertile lands of South India.
Godavri the longest river of South India with a drainage area of 313,000 sq kms flowing with its tributaries in seven different states like Maharashtra, Andhra Pradesh, Karnataka, Madhya Pradesh, Chattisgarh and Orissa. Its branches include Sabari, Indravati, Pranahita and Manijra rivers.
Krishna originates in the Western Ghats at an altitude of 1300 ft above the sea level in Mahabaleshwar and merges into Bay of Bengal flowing through the three states Maharashtra, Karnataka and Andhra Pradesh. it covers an approximate length of 1300 kms.
The coastal rivers are present in the peninsula of India and they drain into the Arabian Sea and Bay of Bengal. The critical rivers which drain into Arabian Sea are Shetrunji, Bhadra, Dhadhar, Vaitarna, Bharathapuzha, Bedti, Sharavati and Periyar. The Shetruni originate near Dalkahwa in Amreli district and Dhandhar near Ghantar village in Panchmahal district in Gujarat which has a 2770 m2 area of basin.
The Sharavati originates in the Shimoga district of Karnataka and has the famous Jog Water Falls. The Bharatpuzha being the longest river in Kerala is also known as the Ponnani. The rivers which drain into the Bay of Bengal are Subarnarekha, Baitarani, Brahmani, Vamsadhara, Penner, Palar and Vaigai. The Vamsadhara rises in the southern part of Odisha through Andhra Pradesh and flows into the Bay of Bengal. The Palar has the basin area of about 17,870 km2. The attributes of the minor coastal rivers are steep gradients, heavy silts and flashy flow. These rivers are the major source of irrigation of agricultural lands in the coastal areas.
As the nature of the land changes, the type of vegetation also changes. The vegetation in the mountainous region would be different from that of plateau region or plain region. Similarly the dry region would have different vegetation than the wet region. The fertile land is used for agricultural purpose where as the undulated grasslands and the rough terrains of the woodlands are a home to variety of animals.
There is a difference in the quality of soil which decides the type of vegetation. The cactus and the thorny bushes are grown in the sandy soil where as the mangroves grow in the deltaic soil. The conical trees can be sighted in the hill slopes which have some depth of soil. The temperature determines the attribute of the vegetation along with the factors like humidity, precipitation and soil.
The fall and the rise of temperature decide the vegetation which ranges from tropical to subtropical temperature and the alpine vegetation in the Himalayas and the hills of the peninsular. The latitude, altitude, season and duration of the day decides the amount and duration of the sunlight. As in summers the duration of sunlight is longer, the trees grow fast in this season.
Soil regions of India
- Aridisols: Northwestern India. Because of Salts content and lack of organic matter the quality of soils and less fertile.
- Alfisols: Northern sections of the Gangetic plain and extending to Kathiawar Peninsula. They are also found in area south of 20 degrees N latitude and along the Coromandel Coast.
- Inceptisols: Found in the Gangetic plains and the Malabar Coast. They are fertile but weakly developed soils.
- Vertisols: An extensive area from north of Mumbai (Bombay) to the Ganges River. These soils are rich in clays and crack deeply during dry periods.
- Ultisols: They are found in northeastern India (Bihar and Orissa).