The surface elevation of the peninsula plateau in the north is nearly 500 m: however, in the south it is up to 1000 m. It has a triangular shape and can be divide into four physiographic regions:
(i) the Deccan Plateau
(ii) the Western Ghats,
(iii) the Eastern Plateau and
(iv) the Eastern Ghats
THE DECCAN PLATEAU is almost plain and slopes towards the east and the south-east. It is a vast
plateau, covering most of the central and southern India. The name Deccan has been derived from
the Prakrit usage dakkhin, which itself has been derived from the Sanskrit word dakshina (south).
It includes the entire Indian peninsula and has an elevation between 1, 500 and 2,500 ft. On its
west, are the Western Ghats and in the east are the Eastern Ghats. The two Ghats form one of the
vertexes of the triangular plateau region having the Vindhya hills on the third side.
It is one of the world’s most stable land masses. It is situated to the south of the Indo-Gangetic
Plain. The Nilgiris sets its boundary while the northern boundary is set by the Satpura and Vindhya
Ranges. The average elevation of the plateau is nearly 500 m. It is made up of black volcanic soil.
The major crop of the region is cotton. Besides cotton, sugarcane, rice and other crops are also
Maharashtra spans over most of the northern part of the plateau, and Chhattisgarh lies in the
north-east corner. Andhra Pradesh is at the east-central part of the plateau and Karnataka covers
the west-central and most of the southern portion of the plateau. Tamil Nadu is at the southernmost
corner of the plateau.
Hyderabad is the largest city of the plateau. It is the joint capital city of the states of Andhra
Pradesh and Telangana. Other major cities are Bangalore, Nagpur, Pune and Sholapur.
The Deccan Plateau is mostly made up of basalt. This is an extrusive igneous rock. In some parts of
the region, we also find granite, an intrusive igneous rock. The difference between these two rock
types are that the basalt rock forms on eruptions of lava, that is, outside a volcano; whereas granite
forms inside a volcano, that is, when the volcano becomes extinct, the lava solidifies inside the
The plateau has a rich mineral deposit. Mineral ores found in this region include mica and iron ore
in the Chhotanagpur region; and diamonds, gold and other metals in the Golconda region.
The period, lasting many hundred years, has seen that there had been a lot of volcanic activity in
the plateau region. The molten lava which had erupted out of the volcanoes became solid and
turned into hard rocks. Layer after layer settled during these many hundreds of years, and with the
extinction of the volcanoes the region of the highlands was formed.
River Godavari and its tributaries drain most parts of the plateau in the north. It originates in the
Western Ghats and drains east towards the Bay of Bengal. The Krishna River and its tributaries also
run from west to east, drain the central portion of the plateau. The southern part of the plateau is
drained by the Cauvery River, which originates in the Western Ghats of Karnataka and flows through
the Nilgiri Hills into Tamil Nadu.
A number of small basins in the region are separated by the low hills. The Vidarbha Plain, the
Godavari Basin and the Bhima basins area separated by low hills such as Ajanta Hills, Balaghat Hills,
Shillong Plateau lies to the east of the peninsular region. Therefore, it is highly dissected and is
covered with dense forests. The average height of the region is between 1, 300 and 1, 800 m. The
highest point is the Shillong peak (1,800m high),
The Chhotanagpur Plateau is a plateau region located in eastern part of India. It expands over
much of the Jharkhand state as well as portions of Orissa, Bihar and Chhattisgarh. Towards its north
lies the Indo-Gangetic Plain and the basin of the Mahanadi River lies to the south.
Deposits of the coal in the Chhotanagpur region support the industries of the Damodar Valley.
Chhotanagpur includes three smaller plateaus, the Ranchi, Hazaribagh and Kodarma Plateaus. The
Ranchi Plateau is the largest of them, having an average height of 700 m.
Most part of the plateau is densely forested, with Sal as the predominant trees. The vegetation
here is that of dry deciduous forest eco-region. The plateau is among the few remaining habitats
remaining in India for tigers and Indian elephants.
The Peninsula in its northern part includes the Satpura Range and the Maharashtra Plateau. The
Maharashtra Plateau is made up of lava and is drained by the River Tapti in the north and river
Godavari in the south. The Satpura runs west-east; in the central parts known as the Mahadeo Hills
and in the eastern it reaches the Maikala Range. The average height of the Karnataka plateau is 500-
800m. The highest hill range is the Baba Budhan Hill tract. The reliefs of the Karnataka and Deccan
Plateaus go up to Kanyakumari.
THE WESTERN GHATS which are also known as the Sahyadri Mountains, form the western edge of
the Deccan strip along the Arabian Sea. The Ghats start from the south of the Tapti River near the
border of Gujarat and Maharashtra, Goa, Karnataka, Kerala and Tamil Nadu are covered by the
The average height of the Western Ghats is approximately 900 m. Higher peaks are found in the
northern part of the Ghats. In Maharashtra, Kalsubai 1, 646 m(5,427 ft), Mahabaleshwar 1,438 m
(4,710 ft) and Harishchandragarh 1, 424 m (4, 691 ft); in south-west Karnataka, Kudremukh at 1, 862
m; and in Kerala Anaimudi are the highest peaks of the Western Ghats. One prominent gap in the
range, the Palghat Gap, joints Tamil Nadu to Kerala.
There are many smaller ranges in the Western Ghats which includes the Nilgiri Hills of the north-
western Tamil Nadu and Biligirirangana towards the south-east of Mysore in Karnataka, the
Shevaroys and Tirumala range farther east, etc. These ranges of the hills function as important
wildlife gateways, which allow species such as elephants to travel between the ranges.
The slopes facing the west in the Ghats receive much more rain than those facing the east. The
Western Ghats are considerably wetter than the dry Deccan to the east. The Western Ghats serve as
the most important water-shed for peninsular India. The abundant rains give rise to a number of
streams, having many waterfalls. They together form the headwaters of the rivers of the Deccan
such as the Godavari River, Krishna, Cauvery River and their tributaries, which fall into Bay of Bengal.
Most of the rivers in the peninsula are threatened by pollution originating from mining, agricultural
and urban runoff, coffee pulp effluents and other human activity. Some strong movements were
launched very recently to check the mining operations in the Western Ghats.
Historically, there were dense forest covers over the Western Ghats. They are the only regions to
contain rainforests of the southern part of India. These forests provide habitat to diverse fauna and
flora, many of them showing affinities to south-east Asia.
They are increasingly facing threats from human activities. Many national parks and other
protected areas are located within the Ghats region; however, only a small portion of the
Western Ghats remains in the unspoiled condition. The Silent Valley National Park in Kerala
is perhaps the last virgin tropical evergreen forests left in India. The Western Ghats also
provides habitat to many endemic species, and the endemism is specially high in the
amphibian and reptilian fauna.
Ecologically, the Western Ghats are different from the regions are comparatively drier. We can
divide the Western Ghats region into four eco-zones. The northern part of the range is drier than the
southern portion, and at lower elevations of the North Western Ghats, the moist deciduous forests
eco-region is made up, with mostly deciduous forests predominated by teak. Tropical moist
deciduous forests are the most commonly found forests in India.
The evergreen Wayanad forests of Kerala and Tamil Nadu determine the separation zone
between the northern and southern eco-zones of the Western Ghats. The southern eco-
zones are wetter and richer in varied species.
At lower height are the South-Western Ghats with moist deciduous forest. We find Cullenia,
teak, dipterocarps and other tree.
These moist forests change into the drier regions as we move southwards of the Deccan
Plateau. Here, we find dry deciduous forests in the mountains’ rain shadow. Over a height of
1, 000 m, the South-Western Ghats montane rain forests are abundant.
The region is cooler and wetter than the surrounding lowland forest. This region is
dominated by evergreen trees along with some montane grasslands and stunted forests. The
South-Western Ghats mountain rain forests are the region with rich varied species.
Nearly Eighty per cent of the flowering plant species of the entire Western Ghats range are
found in this eco-zone. It also gives shelter to the greatest levels of endemism: 35 per cent of
the plants, 42 per cent of the fishes, 48 per cent of the reptiles and 75 per cent of the
amphibians that lives in this eco-region are endemic.
The Eastern Plateau includes the plateaus of Baghelkhand, the Chhotanagpur, the Dandakaranya
along with the Mahanadi Basin. To the north of the Mahanadi is located the Baghelkhand Plateau.
The tributaries of river Sone drain this plateau.
The Chhotanagpur Plateau is made up of granites and gneisses and it covers most part of
Jharkhand. The plateau has an average elevation of 700 m, and it is an old erosional surface.
It is dotted with three lava hills of the Dalma, Porahat and Rajmahal. Damodar River is the
most important river of the region.
The Mahanadi River, with its numerous tributaries, drains the central part of the Eastern
plateau. Towards the south of this basin is located a region having scattered population and
rough topography called the Dandakaranya Plateau.
The Eastern Ghats an irregular range of mountains to the east of the Peninsular region. The range
runs from the state of West Bengal in the north, through Orissa, Andhra Pradesh up to Tamil Nadu in
the south. In Orissa, the Eastern Ghats are popularly known as the Mahendragiri. Here, these are
made up of Khondite and Charnokite gnesses. Towards the south, they are separate low hills known
as Javadi Hills and Shevaroy Hills.
The Eastern Ghats are the eastern extent of the Deccan plateau. They start in the hills of
the Mahanadi River basin and go on to meet the Western Ghats at the southern most tip
of the Peninsula.
The inner region of the Peninsular plateau is known as the Deccan Plateau. The plateau is a series of plateaus
dotted with rolling hills and intersected by numerous rivers. Four major rivers of the south namely
the Godavari, Mahanadi, Krishna and Cauvery erode and cut through the Eastern Ghats. These rivers
originate in the Western Ghats and meet the Bay of Bengal in the east.
The region of the Eastern Ghats is very fertile, but does not support hydropower generation as a
profitable choice as it is in the Western Ghats. The plateau’s average height is between 300 and 750
The Eastern Ghats are not as high as the Western Ghats. The mountain ranges in the
Eastern Ghats also have their local names such as the Velikonda Range of Andhra
Pradesh. The southern most points of the Ghats are the low Sirumalai and
Karanthamalai Hills of southern Tamil Nadu.
To the north of the River Cauvery, in the Tamil Nadu state are located, the hills of
Kollimalai, Pachaimalai, Shevaroy, Chitteri, Palamalai and Mettur. The climate in these
hills is cooler and wetter and is suitable for coffee plantations. The famous hill station of
Yercaud is situated in the Shervaroy Hills.
The nilgiri Hills, running east from the Western Ghats up to the River Cauvery, are a forested
ecological corridor. They connect the Eastern and Western Ghats. Wild elephant population shifts
between the south Eastern Ghats, the Bilgiri and Nilgiri Hills; and the South Western Ghats.
The Nilgiri Hills is the place of convergence of the Western Ghats, the Eastern Ghats, and the
Southern Hills. It has the highest peak of Dodabeta (2,637 m). The famous hill station of
Udagamandulam (Ooty) is also located here.
Rivers Ponnaiyar and Polar originate from the headwater on the Kolar Plateau towards the east. To
the north of the Palar River in the state of Andhra Pradesh, the Eastern Ghats include two parallel
ranges which run from the north towards the south. The lower Velikonda Range is in the east, and
the higher Palikonda- Lankamalla- Nallamalla ranges are in the west. The River Palar flows through
these ranges. The Velikonda range descends to the coastal plain of the Nellore district, while the
Nallamalla range extends up to river Krishna.