PHYSIOGRAPHIC UNITS OF INDIA
AREA KM (Sq) (appro)
% OF TOTAL AREA
Set Up: India takes its standard time
from the meridian of 82 30 E, which is 5 ½ hours
ahead of Greenwich Mean time ( 0
longitude).Pakistan time is 5 hours ahead of GMT
and Bangladesh time is 6 hours ahead of GMT.
Significance of Location: Barring the plateau of Baluchistan (which form part of
Pakistan), the two great ranges of Sulaiman and Kirthar cut it off from the west.
Along the north, the great mountain wall formed by the Hindukush, Karakoram and
the Himalayas, which is difficult to cross, cuts it off from the rest of the continent.
Similarly, the southward of-shoots of the Eastern Himalayas separate it from Russia.
The tropical monsoon climate of India, which ensures a fair supply of moisture and
forms the basis of farming in India, is also a result of its location in the southern part
of Asia. Since the opening of Suez Canal (1867) India’s distance from Europe has
been reduced by 7,000km. It thus bridges the space between the highly industrialized
nation of the west and the semi-arid, and south-western Asia and the most fertile and
populated regions in the south-east and far-east countries.
1. Tropical Rainy climate Region: This region has consistently even temperature, which
stays above 18 C even in December, April, and May are the hottest months, the
temperature varying from 18 C to 27 C. July and August are the coolest months, which
copious rainfall. The average rainfall exceeds 250cm, which encourages wet evergreen
forests. The western coastal strip, Western Ghats, south of Bombay, Meghalaya, western
Nagaland and Tripura come in this climatic region.
2. Tropical Savanna Region: The chief feature of this climate is the long dry period.
Temperature even in winter stay above 18 C, and in summer may even go up to 46 c.
Rainfall, except in the southeastern parts, is in summer and averages about 100cm. In the
south eastern parts, the retreating monsoons bring sufficient rains. A major part of the
southern peninsula, except the arid tract lying east of the Western Ghats, northeastern
Gujarat, south Bihar, major parts of Madhya Pradesh, Orissa, northern Andhra Pradesh,
eastern Maharastra, and eastern TamilNadu coast come under this region.
3. Tropical Steppe Region: The average temperature is over 27 C, the lowest temperature
being about 23 C April and May are the hottest months, when temperature may rise over
30 C. Average rainfall being less than 75cm, the region comprises a part of the famine zone
of the country. The southwest monsoons bring rain to this region. The region comprises the
rain shadow areas lying east of the Western Ghats and covers Karnataka, interior
TamilNadu, western Andhra Pradesh and central Maharastra,
4. Sub-Tropical Steppe Region: The average temperature rises over 27 C and as high 48 C
is recorded during summer. Rainfall from the southwest monsoon averages between 50 to
75 cm. It often fails, leading to widespread drought conditions. This region comprises
tracts stretching and encompassing western Rajasthan and northern Gujarat.
5. Tropical Desert Region: The summer Temperature rises over 48 C, while in winter it
goes down to 1 C. May and June are the hottest months. Average rainfall is 12.5 cm and
very unreliable. Excessive evaporation during summer and intense cold during winter
hinder crop production except through river irrigation. Western Rajasthan and parts of
Kutch, which are purely sandy plains, come in this region.
6. Humid Sub-Tropical Region: Summer temperatures are 46 C to 48 C. Average rainfall,
mostly from summer monsoons, is about 62.5 cm, which increases to over 250cm in the
east. Winters are virtually dry. This region is spread over the foothills of the Himalayas,
eastern Rajasthan, plains of U.P, Bihar, northern Bengal, part of Assam and Arunachal
7. Mountain Region: Average temperature in June is 15 C to 17 C, in winter it goes below
8 C. On the northern slopes of the Himalayas, the rainfall is scanty, about 8-10 cm, but
the western slopes enjoy a heavy rainfall of over 250 cm. The entire Himalayan belt
comprising both the trans-Himalayas and the main Himalayas come under this region.
The Punjab-Haryana Plain: These plains owe their
formation to the Sutlej, the Beas and the Ravi rivers. Many
low lying flood plains (called bets) are found here. The Bari
Doab between Ravi and Beas rivers, the Bist Doab between
the Beas and Sutlej and the Malwa plain are relatively more
The Ganga Plain: The Ganga-Yamuna Doab comprising the
Rohilkhand and the Avadh Plain is the tile area that is
drained by the tributaries of Ganga.
The North Bengal Plains: the Plains extending from the foot
of Eastern Himalayas to the northern limb of Bengal basin
cover an area of 23,000km2.
Brahmaputra Plains: This is a low level plain, rarely more
than 80km broad, surround by High Mountain on all sides
except on the west.
Significance of the Great Plains: Riverine region, Fertile soil,
favorable climate, flat surface, constructions of roads,
extensive system of ABHISHEK
The Deccan Plateau: The Deccan Plateau extends from
the vindhyas to the southern tip of the Peninsula. This triangle
plateau is at its widest in the north. The Vindhya Range and
its eastern extension namely Mahadev hills Kaimuir Hills and
Maikal Range from its northern edge. Western Ghats are
known by different regional names such as the Sahyadris in
Maharastra and Karnataka, the niligris in Tamil Nadu and
Annamalai and the Cardamon hill along the Kerala and Tamil
nadu border. The elevation of the ghats increases towards
the south. The highest peak, Anaimudi (2,695 m) is in Kerala.
The most important gap in the Western Ghats is the Palghat
gap which links Tamil Nadu with Kerala. The Bhorghat and
the Thalghat are other gaps lying in Maharastra state.
Eastern Ghats: These hills rise steeply from the
Coromandel coastal plain. The Eastern Ghats are well
developed in the region between the Godavari and Mahanadi
rivers. The Eastern Ghats and Western Ghats converge in the
Nilgiri hills. Dodda Betta (2,637 m) is the highest peak in the
The Coastal plains: The Peninsular plateau is bounded by coastal plains on
the east and west. There is wide difference between the eastern and
western coastal plain. The west coast is narrower but wet. East coast much
wider but relatively dry. A number of river deltas occur on the east coast.
The deltas of east coast from the ‘granary’ of the five southern statesAndhra Pradesh, Tamil Nadu, Karnataka, Kerala and Pondicherry. The western
coastal strips which have a large number of lagoons and back waters on other
hand are noted for spices, areca nuts, coconuts palms etc.
Western coastal Plain: These lies between the Western Ghats and the
Arabian seas and stretch from Kutch in the north to Kanyakumari in the
south. The Gujarat plain is a broad and flat plain. The Kutch Peninsula, Gulf of
Kutch, and the Gulf of Cambay. The Kathiawar Peninsula, also known as
Saurashtra which lies to the south of Kutch, is also a plain level area except
for some hills rising into Mount Girnar. Sun-divided regionally into the Konkan
coast in Maharastra Canara coast in Karnataka and Malabar Coast in Kerala.
Eastern Coastal Plain: The eastern coastal low lands extend from the mouth
of the Ganga to Kanyakumari. The northern half is called Northern Circars or
Kalinga coast, while the southern half is known as the Coromandal coast. The
border part is the Carnatic region, which is about 480 km wide. They are not
suitable for harbours as their mouths being full of sit.
Significance of Coastal plains: (i) Harbours (ii) Specialized crops (iii)
Fisheries and Navigation (iv) Economic Influence (v) Historical Importance
1.Bay of Bengal Islands: The Andaman & Nicobar group of islands are
separated by 10 Degree channel. These islands have been formed by
extension of tertiary mountain chain of Arakan Yoma. The Andaman
group of island is divided into 3 major groups’ viz., North Andaman,
Middle Andaman and south Andaman, collectively called Great
Andamans. Little Andaman is separated from Great Andamans by
Duncan passage. The Nicobar group of islands of which Great Nicobar is
largest and southern most one. Saddle peak situated in Andaman Islands
is the highest peak of Andaman & Nicobar group.
The Dhuliar peak is the highest peak of Nicobar group of islands.More
habitable and different origin thanofArabian sea islands. Barran island is
dormant volcano and Narcondam island is extinct volcano.
2) Lakshwadeep islands: Coral- More Muslim population and have
fringing reefs. They are 25 small island groups. The island’s north is known
as Amindivi and spot is Cannonore island. Extreme south is Minicoy
islands which is largest.