The mainland comprises four regions,
namely, the great mountain zone, plains of the Ganga and the Indus, the desert
region and the southern peninsula. The Himalayas comprise
three almost parallel ranges interspersed with large plateaus and valleys, some
of which, like the Kashmir and Kullu valleys, are fertile, extensive and of
great scenic beauty. Some of the highest peaks in the world are found in these
ranges. The high altitudes admit travel only to a few passes, notably the Jelep
La and Nathu La on the main Indo-Tibet trade route through the Chumbi Valley,
north-east of Darjeeling and Shipki La in the Satluj valley, north-east of
Kalpa (Kinnaur). The mountain wall extends over a distance of about 2,400 km
with a varying depth of 240 to 320 km. In the east, between India and Myanmar
and India and Bangladesh, hill ranges are much lower. Garo, Khasi, Jaintia and
Naga Hills, running almost east-west, join the chain to Mizo and Rkhine Hills
running north-south.
The plains of the Ganga and
the Indus, about 2,400 km long and 240 to 320 km broad, are formed by basins of
three distinct river systems - the Indus, the Ganga and the Brahmaputra. They
are one of the world's greatest stretches of flat alluvium and also one of the
most densely populated areas on the earth. Between the Yamuna at Delhi and the
Bay of Bengal, nearly 1,600 km away, there is a drop of only 200 metres in
elevation.
The desert region can be
divided into two parts - the great desert and the little desert. The great
desert extends from the edge of the Rann of Kuchch beyond the Luni River
northward. The whole of the Rajasthan-Sind frontier runs through this. The
little desert extends from the Luni between Jaisalmer and Jodhpur up to the
northern wastes. Between the great and the little deserts lies a zone of
absolutely sterile country, consisting of rocky land cut up by limestone
ridges.
The Peninsular Plateau is
marked off from the plains of the Ganga and the Indus by a mass of mountain and
hill ranges varying from 460 to 1,220 metres in height. Prominent among these
are the Aravalli, Vindhya, Satpura, Maikala and Ajanta. The Peninsula is
flanked on the one side by the Eastern Ghats where average elevation is about
610 metres and on the other by the Western Ghats where it is generally from 915
to 1,220 metres, rising in places to over 2,440 metres. Between the Western
Ghats and the Arabian Sea lies a narrow coastal strip, while between Eastern
Ghats and the Bay of Bengal there is a broader coastal area. The southern point
of plateau is formed by the Nilgiri Hills where the Eastern and the Western
Ghats meet. The Cardamom Hills lying beyond may be regarded as a continuation
of the Western Ghats.
Geological Structure
The geological regions broadly follow the physical features, and may be
grouped into three regions: the Himalayas and their associated group of
mountains, the Indo-Ganga Plain, and the Peninsular Shield.
The Himalayan mountain belt to the north and the Naga-Lushai mountain in
the east, are the regions of mountain-building movement. Most of this area, now
presenting some of the most magnificent mountain scenery in the world, was
under marine conditions about 600 million years ago. In a series of
mountain-building movements commencing about 70 million years ago, the
sediments and the basement rocks rose to great heights. The weathering and
erosive agencies worked on these to produce the relief seen today. The
Indo-Ganga plains are a great alluvial tract that separates the Himalayas in
the north from the Peninsula in the south.
The Peninsula is a region of relative stability and occasional seismic
disturbances. Highly metamorphosed rocks of the earliest periods, dating back
as far as 380 crore years, occur in the area; the rest being covered by the
coastal-bearing Gondwana formations, lava flows belonging to the Deccan Trap
formation and younger sediments.
The rivers of India can be classified into four groups viz., Himalayan
rivers, Deccan rivers, Coastal
rivers, and Rivers of the inland drainage basin.
The Himalayan Rivers are formed by melting snow and glaciers and
therefore, continuously flow throughout the year. During the monsoon months,
Himalayas receive very heavy rainfall and rivers swell, causing frequent
floods. The Deccan Rivers on the other hand are rain fed and therefore
fluctuate in volume. Many of these are non-perennial. The Coastal streams,
especially on the west coast are short in length and have limited catchment's
areas. Most of them are non-perennial. The streams of inland drainage basin of
western Rajasthan are few. Most of them are of an ephemeral character.
The main Himalayan river systems are those of the Indus and the
Ganga-Brahmaputra-Meghna system. The Indus, which is one of the great rivers of
the world, rises near Mansarovar in Tibet and flows through India, and
thereafter through Pakistan, and finally falls in the Arabian Sea near Karachi.
Its important tributaries flowing in Indian Territory are the Sutlej
(originating in Tibet), the Beas, the Ravi, the Chenab, and the Jhelum. The
Ganga-Brahmaputra-Meghna is another important system of which the principal
sub-basins are those of Bhagirathi and the Alaknanda, which join at Dev Prayag
to form the Ganga. It traverses through Uttarakhand, Uttar Pradesh, Bihar, and
West Bengal. Below Rajmahal hills, the Bhagirathi, which used to be the main
course in the past, takes off, while the Padma continues eastward and enters
Bangladesh. The Yamuna, the Ramganga, the Ghaghra, the Gandak, the Kosi, the
Mahananda and the Sone are the important tributaries of the Ganga. Rivers
Chambal and Betwa are the important sub-tributaries, which join Yamuna before
it meets the Ganga. The Padma and the Brahmaputra join inside Bangladesh, and
continue to flow as the Padma or Ganga. The Brahmaputra rises in Tibet, where
it is known as Tsangpo and runs a long distance till it crosses over into India
in Arunachal Pradesh under the name of Dihang. Near Passighat, the Debang and
Lohit join the river Brahmaputra and the combined river runs all along the
Assam in a narrow valley. It crosses into Bangladesh downstream of Dhubri.
The principal tributaries of Brahmaputra in India are the Subansiri, Jia
Bhareli, Dhansiri, Puthimari, Pagladiya and the Manas. The Brahmaputra in
Bangladesh receives the flow of Tista, etc., and finally falls into Ganga. The
Barak River, the Head stream of Meghna, rises in the hills in Manipur. The
important tributaries of the river are Makku, Trang, Tuivai, Jiri, Sonai,
Rukni, Katakhal, Dhaleswari, Langachini, Maduva and Jatinga. Barak continues in
Bangladesh till the combined Ganga-Brahmaputra join it near Bhairab Bazar.
In the Deccan region, most of the major river systems flowing generally
in east direction fall into Bay of Bengal. The major east flowing rivers are
Godavari, Krishna, Cauvery, Mahanadi, etc. Narmada and Tapti are major West
flowing rivers.
The Godavari in the southern Peninsula has the second largest river
basin covering 10 per cent of the area of India. Next to it is the Krishna
basin in the region, while the Mahanadi has the third largest basin. The basin
of the Narmada in the uplands of the Deccan, flowing to the Arabian Sea, and of
the Kaveri in the south, falling into the Bay of Bengal are about the same
size, though with different character and shape.
There are numerous coastal rivers, which are comparatively small. While
only handful of such rivers drain into the sea near the delta of east cost,
there are as many as 600 such rivers on the west coast.
A few rivers in Rajasthan do not drain into the sea. They drain into
salt lakes and get lost in sand with no outlet to sea. Besides these, there are
the Desert Rivers which flow for some distance and are lost in the desert. These
are Luni and others such as, Machhu, Rupen, Saraswati, Banas and Ghaggar.
The climate of India may be
broadly described as tropical monsoon type.
There are four seasons:
- winter (December-February)
- hot weather summer
(March-May)
- rainy southwestern monsoon
(June-September) and
- post-monsoon, also known as
northeast monsoon in the southern Peninsula (October-December).
India's climate is affected
by two seasonal winds - the northeast monsoon and the southwest monsoon. The
north-east monsoon, commonly known as winter monsoon blows from land to sea,
whereas south-west monsoon, known as summer monsoon blows from sea to land
after crossing the Indian Ocean, the Arabian Sea, and the Bay of Bengal. The
south-west monsoon brings most of the rainfall during a year in the country.
With a wide range of climatic conditions from the torrid to the arctic,
India has a rich and varied vegetation, which only a few countries of
comparable size possess. India can be divided into eight
distinct-floristic-regions, namely, the western Himalayas, the eastern
Himalayas, Assam, the Indus plain, the Ganga plain, the Deccan, Malabar and the
Andamans.
The Western Himalayan region extends from Kashmir to Kumaon. Its
temperate zone is rich in forests of chir, pine, other conifers and
broad-leaved temperate trees. Higher up, forests ofdeodar, blue pine, spruce and
silver fir occur. The alpine zone extends from the upper limit of the temperate
zone of about 4,750 metres or even higher. The characteristic trees of this
zone are high-level silver fir, silver birch and junipers. The eastern
Himalayan region extends from Sikkim eastwards and embraces Darjeeling,
Kurseong and the adjacent tract. The temperate zone has forests of oaks,
laurels, maples, rhododendrons, alder and birch. Many conifers, junipers and
dwarf willows also occur here. The Assam region comprises the Brahmaputra and
the Surma valleys with evergreen forests, occasional thick clumps of bamboos
and tall grasses. The Indus plain region comprises the plains of Punjab,
western Rajasthan and northern Gujarat. It is dry and hot and supports natural
vegetation. The Ganga plain region covers the area which is alluvial plain and
is under cultivation for wheat, sugarcane and rice. Only small areas support
forests of widely differing types. The Deccan region comprises the entire
tableland of the Indian Peninsula and supports vegetation of various kinds from
scrub jungles to mixed deciduous forests. The Malabar region covers the
excessively humid belt of mountain country parallel to the west coast of the
Peninsula. Besides being rich in forest vegetation, this region produces
important commercial crops, such as coconut, betel nut, pepper, coffee and tea,
rubber and cashew nut. The Andaman region abounds in evergreen, mangrove, beach
and diluvia forests. The Himalayan region extending from Kashmir to Arunachal
Pradesh through Nepal, Sikkim, Bhutan, Meghalaya and Nagaland and the Deccan
Peninsula is rich in endemic flora, with a large number of plants which are not
found elsewhere.
India is rich in flora. Available data place India in the tenth position
in the world and fourth in Asia in plant diversity. From about 70 per cent
geographical area surveyed so far, 47,000 species of plants have been described
by the Botanical Survey of India (BSI), Kolkata. The vascular flora, which
forms the conspicuous vegetation cover, comprises 15,000 species. Of these,
more than 35 per cent is endemic and has so far not been reported anywhere in
the world. The flora of the country is being studied by the BSI and its nine
circle/field offices located throughout the country along with certain
universities and research institutions.
Ethno-botanical study deals with the utilisation of plants and plant
products by ethnic races. A scientific study of such plants has been made by
BSI. A number of detailed ethno-botanical explorations have been conducted in
different tribal areas of the country. More than 800 plant species of
ethno-botanical interest have been collected and identified at different
centres.
Owing to destruction of forests for agricultural, industrial and urban
development, several Indian plants are facing extinction. About 1,336 plant
species are considered vulnerable and endangered. About 20 species of higher
plants are categorised as possibly extinct as these have not been sighted
during the last 6-10 decades. BSI brings out an inventory of endangered plants
in the form of a publication titled Red Data Book.
The Zoological Survey of India (ZSI), with its headquarters in Kolkata
and 16 regional stations is responsible for surveying the faunal resources of
India. Possessing a tremendous diversity of climate and physical conditions,
India has great variety of fauna, numbering 89,451 species, which include
protista, mollusca, anthropoda, amphibia, mammalia, reptilia, members of
protochordata, pisces, aves and other invertebrates.
The mammals include the majestic elephant, the gaur or Indian bison - the largest of
existing bovines, the great Indian rhinoceros, the gigantic wild sheep of the
Himalayas, the swamp deer, the thamin spotted deer, nilgai,
the four-horned antelope, the Indian antelope or black-buck - the only
representatives of these genera. Among the cats, the tiger and lion are the
most magnificent of all; other splendid creatures such as the clouded leopard,
the snow leopard, the marbled cat, etc., are also found. Many other species of
mammals are remarkable for their beauty, colouring, grace and uniqueness.
Several birds, like pheasants, geese, ducks, mynahs, parakeets, pigeons,
cranes, hornbills and sun birds inhabit forests and wetlands.
Rivers and lakes harbour crocodiles and gharials,
the latter being the only representative of crocodilian order in the world. The
salt-water crocodile is found along the eastern coast and in the Andaman and
Nicobar Islands. A project for breeding crocodiles, started in 1974, has been
instrumental in saving the crocodile from extinction.
The great Himalayan range has a very interesting variety of fauna that
includes the wild sheep and goats, markhor, ibex, shrew and tapir. The panda
and the snow leopard are found in the upper reaches of the mountains.
Depletion of vegetative cover due to expansion of agriculture, habitat
destruction, over-exploitation, pollution, introduction of toxic imbalance in
community structure, epidemics, floods, droughts and cyclones, contribute to
the loss of flora and fauna. More than 39 species of mammals, 72 species of
birds, 17 species of reptiles, three species of amphibians, two species of
fish, and a large number of butterflies, moth, and beetles are considered
vulnerable and endangered.
Indian Union and its Territory
India comprises 28 States and 7 Union Territories. They are:
States:
- Andhra Pradesh
- Assam
- Arunachal Pradesh
- Bihar
- Chhattisgarh
- Goa
- Gujarat
- Haryana
- Himachal Pradesh
- Jammu & Kashmir
- Jharkhand
- Karnataka
- Kerala
- Madhya Pradesh
- Maharashtra
- Manipur
- Meghalaya
- Mizoram
- Nagaland
- Odisha
- Punjab
- Rajasthan
- Sikkim
- Tamil Nadu
- Tripura
- Uttarakhand
- Uttar Pradesh
- West Bengal
Union Territories:
- Andaman and Nicobar Islands
- Chandigarh
- Dadra and Nagar Haveli
- Daman and Diu
- National Capital Territory of Delhi
- Lakshadweep
- Puducherry
