Physiographic Regions- 2 | Geography Optional for UPSC (Notes) PDF Download

Features of the Peninsular Plateau

• The Peninsular Plateau is a roughly triangular-shaped region situated in southern India, with its base aligning with the southern edge of North India's great plain. Kanniyakumari marks the apex of this triangular plateau. Covering an area of approximately 1.6 million square kilometers, the plateau constitutes about half of India's total land area (3.2 million square kilometers).
• The average elevation of the plateau ranges between 600-900 meters above sea level, though this height varies across different regions. Most of the rivers flowing through the Peninsular Plateau run from west to east, indicating the general slope of the region. However, the Narmada-Tapti rivers are an exception, as they flow from east to west in a rift, which is caused by a divergent boundary.
• The Peninsular Plateau is one of the Earth's oldest landforms and is primarily composed of Archaean gneisses and schists. This highly stable block has experienced minimal structural changes since its formation. Over the past few hundred million years, the Peninsular region has predominantly been a land area, with only a few places ever being submerged beneath the sea.
• This plateau is an amalgamation of several smaller plateaus, hill ranges, river basins, and valleys, creating a diverse and unique landscape.

Peninsular Plateau

Minor Plateaus in the Peninsular Plateau

Marwar Plateau

• The Marwar Plateau, also known as the Mewar Plateau, is situated in eastern Rajasthan, India. It lies to the east of the Aravali Range, while the Marwar plain is located to the west. The plateau has an average elevation of 250-500 meters above sea level and gradually slopes downwards towards the east.
• The geological composition of the Marwar Plateau consists of sandstone, shales, and limestones from the Vindhayan period. The Banas River, along with its tributaries such as the Berach and Khari rivers, originates in the Aravali Range and flows northwest into the Chambal River. The action of these rivers eroding the plateau gives it the appearance of a rolling plain.
• A rolling plain is a type of landform that is not entirely flat but features gentle rises and falls in elevation. An example of a rolling plain can be found in the prairies of the United States. The Marwar Plateau's rolling plain-like appearance is due to the erosional actions of the Banas River and its tributaries.

Central Highland

• Also called the Madhya Bharat Pathar or Madhya Bharat Plateau.
• It is to the east of the Marwar or Mewar Upland.
• Most of the plateau comprises the basin of the Chambal river which flows in a rift valley.
• The Kali Sindh, flowing from Rana Pratap Sagar, The Banas flowing through Mewar plateau, and The Parwan and the Parbati flowing from Madhya Pradesh are its main tributaries.
• It is a rolling plateau with rounded hills composed of sandstone. Thick forests grow here.
• To the north are the ravines or badlands of the Chambal river [They are typical to Chambal river basin].

Central Highlands 

Bundelkhand Upland
The Bundelkhand Upland is a region located in central India, encompassing parts of Uttar Pradesh and Madhya Pradesh. It is bordered by the Yamuna River to the north, the Madhya Bharat Pathar to the west, the Vindhyan Scarplands to the east and southeast, and the Malwa Plateau to the south.

• The landscape is primarily composed of old, dissected uplands made up of Bundelkhand gneiss, which includes granite and gneiss rock formations. The region spans across five districts in Uttar Pradesh and four districts in Madhya Pradesh.
• The Bundelkhand Upland has an average elevation of 300-600 meters above sea level and slopes down from the Vindhyan Scarp towards the Yamuna River. The terrain is characterized by small hills, also known as hillocks, made of granite and sandstone.

Bundelkhand Upland

• Over time, the rivers that flow through this region, such as the Betwa, Dhasan, and Ken rivers, have eroded the landscape, creating a wave-like surface that is unsuitable for cultivation. As a result, the region has a topography that resembles features typically associated with old age.
• In summary, the Bundelkhand Upland is a region in central India that consists of old, dissected uplands made of granite and gneiss rock formations. It is characterized by an undulating landscape, with small hills and valleys created by the erosional work of rivers flowing through the area. This region's topography makes it unsuitable for cultivation and gives it an appearance characteristic of an aged landscape.

Malwa Plateau

• The Malwa Plateau roughly forms a triangle based on the Vindhyan Hills, bounded by the Aravali Range in the west and Madhya Bharat Pathar to the north, and Bundelkhand to the east.
• This plateau has two systems of drainage; one towards the Arabian sea (The Narmada, the Tapi, and the Mahi), and the other towards the Bay of Bengal (Chambal and Betwa, joining the Yamuna).
• In the north, it is drained by the Chambal and many of its right bank tributaries like the Kali, the Sindh, and the Parbati. It also includes the upper courses of the Sindh, the Ken, and the Betwa.
• It is composed of the extensive lava flow and is covered with black soils.

Malwa Plateau

• The general slope is towards the north [decreases from 600 m in the south to less than 500 m in the north]
• This is a rolling plateau dissected by rivers. In the north, the plateau is marked by the Chambal ravines.

Baghelkhand

• North of the Maikal Range is the Baghelkhand.
• Made of limestones and sandstones on the west and granite in the east.
• It is bounded by the Son river on the north.
• The central part of the plateau acts as a water divide between the Son drainage system in the north and the Mahanadi river system in the south.
• The region is uneven with general elevation varying from 150 m to 1,200 m.
• The Bharner and Kaimur are located close to the trough-axis.
• The general horizontality of the strata shows that this area has not undergone any major disturbance.

Rohtas Plateau

• The Rohtas Plateau (also referred to as Kaimur Plateau) is a plateau that lies in the south-western part of Bihar.

• The Rohtas Plateau or Kaimur Plateau comprises about 800 square miles (2,100 km²). It is an undulating table land. At Rohtasgarh it attains a height of 1,490 feet (450 m) above sea level. 
• Surrounding geography: A series of fluvial plateaux that run along the Kaimur Range consist of a series of descending plateaux, starting with the Panna Plateau in the west, followed by Bhander Plateau and Rewa Plateau and ending with Rohtas plateau in the east.

Bhander Plateau

• The Bhander Plateau is a plateau in the state of Madhya Pradesh in India. It has an area of 10,000 square kilometres.
• It links the Deccan Plateau to the south with the Indo-Gangetic Plains and the Chota Nagpur Plateau to the north and east respectively.
• The plateau is part of the Vindhya Range in central India.
• A series of plateaux runs along the Kaimur Range. These fluvial plateaux consist of a series of descending plateaux, starting with the Panna Plateau in the west, followed by Bhander Plateau and Rewa Plateau, and ending with Rohtas Plateau in the east.

Chotanagpur Plateau

• The Chotanagpur Plateau is a prominent geographical feature located in the northeastern part of the Indian Peninsula. It primarily spans across the state of Jharkhand, the northern region of Chhattisgarh, and the Purulia district in West Bengal. The plateau is bordered by the Son River on its northwestern side, which eventually merges with the Ganga River.
• With an average elevation of 700 meters above sea level, the Chotanagpur Plateau is mainly composed of Gondwana rocks. The region features a radial drainage pattern, with numerous rivers and streams flowing in various directions. Some of the prominent rivers include the Damodar, Subarnrekaha, North Koel, South Koel, and Barkar, all of which have formed extensive drainage basins.

Chotanagpur Plateau

• The Damodar River, in particular, flows through the heart of the Chotanagpur Plateau in a rift valley from west to east. This area is home to the Gondwana coal fields, which are a major source of coal in India. The Hazaribagh Plateau, situated north of the Damodar River, has an average elevation of 600 meters above sea level and features isolated hills. Large-scale erosion has given it a peneplain-like appearance.
• To the south of the Damodar Valley lies the Ranchi Plateau, which has an elevation of around 600 meters above sea level. The city of Ranchi, with an elevation of 661 meters, is located in this region, which has a predominantly rolling landscape. In some areas, the plateau is punctuated by monadnocks and conical hills.
• The Rajmahal Hills, which form the northeastern boundary of the Chotanagpur Plateau, are primarily composed of basalt and are covered by lava flows. These hills extend in a north-south direction and have an average elevation of 400 meters, with the highest peak reaching 567 meters. The Rajmahal Hills have been dissected into separate plateaus due to erosion.

Meghalaya Plateau

• The Meghalaya Plateau, also known as the Shillong Plateau, is an extension of the peninsular plateau that stretches eastward beyond the Rajmahal Hills. It is separated from the main block by the Garo-Rajmahal Gap, which was formed due to down-faulting, where a block of earth slides downwards. The gap was later filled with sediments deposited by the Ganga and Brahmaputra rivers.
• The down warping along the Rajmahal-Garo Hills created the 'Malda gap,' through which the Ganga-Brahmaputra rivers flow. The Meghalaya Plateau is composed of Archaean quartzites, shales, and schists. It slopes down towards the Brahmaputra Valley in the north and the Surma and Meghna valleys in the south. The plateau's western boundary roughly aligns with the Bangladesh border.
• The Meghalaya Plateau is divided into three parts: the Garo Hills in the west, with an average elevation of 900 meters; the Khasi-Jaintia Hills in the central region, with an elevation of 1,500 meters; and the Mikir Hills in the east, with an elevation of 700 meters. The highest point of the plateau is Shillong, which stands at an elevation of 1,961 meters.

Deccan Plateau

• It covers an area of about five lakh sq km.
• It is triangular in shape and is bounded by the Satpura and the Vindhya in the north-west, the Mahadev and the Maikal in the north, the Western Ghats in the west, and the Eastern Ghats in the east.

• Its average elevation is 600 m.
• It rises to 1000 m in the south but dips to 500 m in the north.
• Its general slope is from west to east which is indicated by the flow of its major rivers.
• Rivers have further subdivided this plateau into a number of smaller plateaus.

Maharashtra Plateau

• The Maharashtra Plateau lies in Maharashtra.
• It forms the northern part of the Deccan Plateau.
• Much of the region is underlain by basaltic rocks of lava origin [Most of the Deccan Traps lies in this region].
• The area looks like a rolling plain due to weathering.
• The horizontal lava sheets have led to the formation of typical Deccan Trap topography [step like].
• The broad and shallow valleys of the Godavari, the Bhima, and the Krishna are flanked [bordered on the opposite sides] by flat-topped steep-sided hills and ridges.
• The entire area is covered by black cotton soil known as regur.

Karnataka Plateau

• The Karnataka Plateau is also known as the Mysore plateau.
• Lies to the south of the Maharashtra plateau.
• The area looks like a rolling plateau with an average elevation of 600-900 m.
• It is highly dissected by numerous rivers rising from the Western Ghats.
• The general trend of the hills is either parallel to the Western Ghats or across it.
• The highest peak (1913 m) is at Mulangiri in Baba Budan Hills in the Chikmaglur district.
• The plateau is divided into two parts called Malnad and Maidan.
• The Malnad in Kannada means the hill country. It is dissected into deep valleys covered with dense forests.
• The Maidan on the other hand is formed of a rolling plain with low granite hills.
• The plateau tapers between the Western Ghats and the Eastern Ghats in the south and merges with the Niligiri hills there.

Telangana Plateau

• The Telangana plateau consists of Archaean gneisses.
• It is made up of Dharwar rocks. Gondwana rocks are also found in the Godavari valley, famous for its coal fields.
• Because of the Dharwar rock strata, the plateau is rich in mineral resources.
• Its average elevation is 500-600 m.
• The southern part is higher than its northern counterpart.
• The region is drained by three river systems, the Godavari, the Krishna, and the Penner.
• The entire plateau is divided into Ghats and the Peneplains (a vast featureless, undulating plain which the last stage of the deposition process).

Bastar Plateau

• Bastar is a district in the southernmost region in the state of Chhattisgarh.
• It is a forested mineral rich region.
• Southern part of Chhattisgarh between the Mahanadi and Godavari rivers.
• Bisected into two parts by the Indravati River.
• Tribal dominated region.
• Under the strong grip of Naxalism.

Chhattisgarh Plain

• The Chhattisgarh plain is the only plain worth the name in the Peninsular plateau.
• It is a saucer-shaped depression drained by the upper Mahanadi.
• The whole basin lies between the Maikala Range and the Odisha hills.
• The region was once ruled by Haithaivanshi Rajputs from whose thirty-six forts (Chhattisgarh) it derives its name.
• The basin is laid with nearly horizontal beds of limestone and shales.
• The general elevation of the plain ranges from 250 m in the east to 330 m in the west.

Dandakaranya Plateau

• The Dandakaranya Plateau is a historical region in India, mentioned in the Ramayana. It is situated in the Bastar region of the current state of Chhattisgarh, in the central part of India. The plateau is a physiographic area that spans approximately 35,600 square miles, encompassing the Abujhmad Hills in the west and extending to the Eastern Ghats in the east.
• The Abujmarh region is a hilly forest area within Chhattisgarh, covering the districts of Narayanpur, Bijapur, and Dantewada. This region is home to various indigenous tribes of India, such as the Gond, Muria, Abuj Maria, and Halbaas.
• The Dandakaranya Plateau comprises parts of the states of Chhattisgarh, Odisha, Telangana, and Andhra Pradesh. It stretches roughly 200 miles from north to south and about 300 miles from east to west.

The Indian coastline which is 7516.6 km long covers 6100 km of mainland coastline along with the Andaman, Nicobar, and the Lakshadweep islands.
The straight and regular coastline of India is the result of the faulting of the Gondwana land during the Cretaceous period.
The coastline of India touches 13 states and Union Territories. The western coastal plains are along the Arabian Sea whereas the eastern coastal plains are located along the Bay of Bengal.
India is a country that is surrounded by the sea on three of its sides. The coastal plains in India are along the west and east of the country.  Extending up to 7516.6 km, the coastal plains in India are of two types:

• Western Coastal Plains of India
• Eastern Coastal Plains of India

West Coast of India

West Coastal PlainsThe west coast strip extends from the Gulf of Cambay (Gulf of Khambhat) in the north to Cape Comorin (Kanniyakumari).

• Starting from north to south, it is divided into (i) the Konkan coast, (ii) the Karnataka coast and (iii) the Kerala cost.
• It is made up of alluvium brought down by the short streams originating from the Western Ghats.
• It is dotted with a large number of coves (a very small bay), creeks (a narrow, sheltered waterway such as an inlet in a shoreline or channel in a marsh) and a few estuaries. {Marine Landforms}
• The estuaries, of the Narmada and the Tapi are the major ones.
• The Kerala coast (Malabar Coast) has some lakes, lagoons and backwaters, the largest being the Vembanad Lake.

Western Coastal Plains of India

• Rann of Kachchh in the north to Kanniyakumari in the South.
• These are narrow plains with an average width of about 65 km.
• Western coast is mainly divided into four categories
  • Kachchh and Kathiawar coast
  • Konkan coast
  • Kanada coast
  • Malabar coast

Kutch and Kathiawar Region

• The Kutch and Kathiawar regions, although considered extensions of the Peninsular Plateau due to the presence of Deccan Lava in Kathiawar and tertiary rocks in Kutch, are still regarded as integral parts of the Western Coastal Plains due to their leveled terrain.
• The Kutch Peninsula was once an island surrounded by seas and lagoons, but over time, the sediment carried by the Indus River filled these water bodies and transformed the landscape. Nowadays, the region is characterized by its arid and semi-arid conditions due to a lack of rainfall.
• To the north of Kutch lies the Great Rann, a salt-soaked plain, while its southern counterpart - the Little Rann - can be found on the coast and southeast of Kutch. These two areas form a continuous stretch of unique landscape.
• The Kathiawar Peninsula is located south of Kutch, with the central part featuring the highland of Mandav Hills. From these hills, small streams radiate in all directions, exhibiting radial drainage. The highest point in the region is Mount Girnar, standing at 1,117 meters and formed by volcanic activity.
• In the southern part of the Kathiawar peninsula, one can find the Gir Range, which is covered with dense forests and is renowned as the home of the Gir lion. This area is known for its rich biodiversity and natural beauty.

Gujarat Plain

• The Gujarat Plain lies east of Kachchh and Kathiawar and slopes towards the west and south west.
• Formed by the rivers Narmada, Tapi, Mahi and Sabarmati, the plain includes the southern part of Gujarat and the coastal areas of the Gulf of Khambhat.
• The eastern part of this plain is fertile enough to support agriculture, but the greater part near the coast is covered by windblown loess (heaps of sand).

Konkan Plain

• The Konkan Plain south of the Gujarat plain extends from Daman to Goa (50 to 80 km wide).
• It has some features of marine erosion including cliffs, shoals, reefs and islands in the Arabian Sea.
• The Thane creek around Mumbai is an important embayment (a recess in a coastline forming a bay) which provides an excellent natural harbour.

Karnataka Coastal Plain

• Goa to Mangalore.
• It is a narrow plain with an average width of 30-50 km, the maximum being 70 km near Mangalore.
• At some places the streams originating in the Western Ghats descend along steep slopes and make waterfalls.
• The Sharavati while descending over such a steep slope makes an impressive waterfall known as Gersoppa (Jog) Falls which is 271 m high. [Angel falls (979 m) in Venezuela is the highest waterfall on earth. Tugela Falls (948 m) in Drakensberg mountains in South Africa is the second highest.]
• Marine topography is quite marked on the coast.

Malabar Plain (Kerala Plain)

• The Kerala Plain is also known as the Malabar Plain.
• Between Mangalore and Kanniyakumari.
• This is much wider than the Karnataka plain. It is a low-lying plain.
• The existence of lakes, lagoons, backwaters, spits, etc. is a significant characteristic of the Kerala coast.
• The backwaters, locally known as kayals are the shallow lagoons or inlets of the sea, lying parallel to the coastline.
• The largest among these is the Vembanad Lake which is about 75 km long and 5-10 km wide and gives rise to a 55 km long spit {Marine Landforms}.

East Coast of India

• Lies between the Eastern Ghats and the Bay of Bengal.
• It extends from the Ganga delta to Kanniyakumari.
• It is marked by deltas of rivers like the Mahanadi, the Godavari, the Krishna, and the Cauvery.
• Chilka lake and the Pulicat lake (lagoon) are the important geographical features of the east coast.

Eastern Coastal Plains of India

East Coastal PlainsExtending from the Subarnarekha river along the West Bengal-Odisha border to Kanniyakumari.

• A major part of the plains is formed as a result of the alluvial fillings of the littoral zone (relating to or on the shore of the sea or a lake) by the rivers Mahanadi, Godavari, Krishna and Cauvery comprising some of the largest deltas.
• In contrast to the West Coastal Plains, these are extensive plains with an average width of 120 km.
• This plain is known as the Northern Circars between the Mahanadi and the Krishna rivers and Carnatic between the Krishna and the Cauvery rivers.
• Eastern coast is divided into three categories-
  • Utkal coast
  • Andhra coast
  • Coromandel coast

Utkal Plain

• The Utkal Plain comprises coastal areas of Odisha.
• It includes the Mahanadi delta.
• The most prominent physiographic feature of this plain is the Chilka Lake.
• It is the biggest lake in the country and its area varies between 780 sq km in winter to 1,144 sq km in the monsoon months.
• South of Chilka Lake, low hills dot the plain.

Andhra Plain

• South of the Utkal Plain and extends upto Pulicat Lake. This lake has been barred by a long sand spit known as Sriharikota Island (ISRO launch facility).
• The most significant feature of this plain is the delta formation by the rivers Godavari and Krishna.
• The two deltas have merged with each other and formed a single physiographic unit.
• The combined delta has advanced by about 35 km towards the sea during the recent years. This is clear from the present location of the Kolleru Lake which was once a lagoon at the shore but now lies far inland {Coastline of Emergence}.
• This part of the plain has a straight coast and badly lacks good harbours with the exception of Vishakhapatnam and Machilipatnam.

Tamil Nadu Plain

• The Tamil Nadu Plain stretches for 675 km from Pulicat lake to Kanniyakumari along the coast of Tamil Nadu. Its average width is 100 km.
• The most important feature of this plain is the Cauvery delta where the plain is 130 km wide.
• The fertile soil and large scale irrigation facilities have made the Cauvery delta the granary of South India.

Coastlines of Emergence and Submergence

• A coastline of emergence is created when the land rises or the sea level drops, while a coastline of submergence is the exact opposite, formed when the land sinks or the sea level rises. Various marine landforms, such as bars, spits, lagoons, salt marshes, beaches, sea cliffs, and arches, are characteristic features of emergent coastlines.
• In India, the east coast, particularly the southeastern part (Tamil Nadu coast), is considered to be a coastline of emergence. Conversely, the west coast of India exhibits both emergent and submergent characteristics. The northern portion of the west coast is submerged due to faulting, while the southern portion, the Kerala coast, serves as an example of an emergent coast.
• To summarize, the Coromandel coast (Tamil Nadu) is a coastline of emergence, the Malabar coast (Kerala Coast) is also a coastline of emergence, and the Konkan coast (Maharashtra and Goa Coast) is a coastline of submergence.

Significance of Indian Coastlines

• The Indian coastline stretches for an impressive 7,516.6 km, including the island groups of Andaman and Nicobar and Lakshadweep. This vast stretch of coastline has a significant impact on various aspects of life in the country, including climate, agriculture, trade, natural resources, and tourism.
• The climate in the coastal regions of India is typically moderate, with no extreme temperatures, which creates an ideal environment for human development and progress. The coastal plains are known to have fertile soil, making them highly conducive to agricultural production. Rice is the primary crop cultivated in these areas, contributing significantly to the country's food supply.
• India's extensive coastline also enables the development of numerous ports, both large and small, which play a crucial role in facilitating trade and commerce. These ports not only boost the local economy but also contribute to the overall growth of the nation.
• Another significant aspect of India's coastlines is the potential for marine resources. The sedimentary rocks found in the coastal plains are believed to contain vast deposits of mineral oil, which can be harnessed to strengthen the country's marine economy.
• Fishing is a vital occupation for the people living in coastal areas, providing not only sustenance but also livelihood opportunities for many. The fishing industry is a significant contributor to the overall economy and has the potential for further growth.
• Lastly, the coastal plains of India are home to diverse coastal and marine ecosystems, including mangroves, coral reefs, estuaries, and lagoons. These natural wonders offer immense tourism potential, attracting visitors from around the world and generating revenue for the local communities and the country as a whole.

In summary, the Indian coastlines play a significant role in various aspects of life in the country, including agriculture, trade, natural resources, fishing, and tourism. The favorable climate and fertile soil of the coastal plains, coupled with the potential for marine resource development and the rich biodiversity, make India's coastlines an essential part of the nation's growth and progress.

Conclusion

Frequently Asked Questions (FAQs) of Physiographic Regions

What are the main features of the Peninsular Plateau in India?

The Peninsular Plateau is a roughly triangular-shaped region situated in southern India, with an average elevation of 600-900 meters above sea level. It is one of the Earth's oldest landforms, primarily composed of Archaean gneisses and schists. The plateau is an amalgamation of several smaller plateaus, hill ranges, river basins, and valleys, creating a diverse and unique landscape.

How does the Indian coastline influence the country's climate and agriculture?

The climate in the coastal regions of India is typically moderate, with no extreme temperatures, which creates an ideal environment for human development and progress. The coastal plains are known to have fertile soil, making them highly conducive to agricultural production. Rice is the primary crop cultivated in these areas, contributing significantly to the country's food supply.

What is the significance of India's ports along its extensive coastline?

India's extensive coastline enables the development of numerous ports, both large and small, which play a crucial role in facilitating trade and commerce. These ports not only boost the local economy but also contribute to the overall growth of the nation.

How does the fishing industry contribute to India's coastal economy?

Fishing is a vital occupation for the people living in coastal areas, providing not only sustenance but also livelihood opportunities for many. The fishing industry is a significant contributor to the overall economy and has the potential for further growth.

What are some of the unique coastal and marine ecosystems found along India's coastline, and how do they contribute to tourism?

The coastal plains of India are home to diverse coastal and marine ecosystems, including mangroves, coral reefs, estuaries, and lagoons. These natural wonders offer immense tourism potential, attracting visitors from around the world and generating revenue for the local communities and the country as a whole.