Countries having a common border with India are Afghanistan and Pakistan to the north-west, China, Bhutan and Nepal to the north, Myanmar to the far east and Bangladesh to the east.
Sri Lanka is separated from India by a narrow channel of sea formed by the Palk Strait and the Gulf of Mannar.
It covers an area of 32,87,263 sq. km. The country can be divided into six zones mainly north, south, east, west, central and northeast zone. It has 28 states and nine union territories.
India is the seventh-largest country in the world and ranks second in population.
Lying entirely in the Northern Hemisphere, the mainland extends between latitudes 8°4’ and 37°6’ north, longitudes 68°7’ and 97°25’ east and measures about 3,214 km from north to south between the extreme latitudes and about 2,933 km from east to west between the extreme longitudes.
It has a land frontier of about 15,200 km. The total length of the coastline of the mainland, Lakshadweep Islands and Andaman and Nicobar Islands is 7,516.6 km.
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 high altitudes of the Himalayas allow travel only through 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 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.
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 Kutch beyond the Luni river northward. The little desert extends from the Luni between Jaisalmer and Jodhpur up to the northern west.
The Peninsular Plateau is marked off from the plains by a mass of mountain and hill ranges. Prominent among these are the Aravali, Vindhya, Satpura, Maikala and Ajanta. The Peninsula is flanked on the one side by the Eastern Ghats and on the other by the Western Ghats.
Between the Western Ghats and the Arabian Sea lies a narrow coastal strip, while between the Eastern Ghats and the Bay of Bengal, there is a broader coastal area.
The southern point of the 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.
The geological regions may be grouped into three regions: the Himalayas and their associated group of mountains, the Indo-Gangetic 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.
The Indo-Ganga plains are a great alluvial tract that separate the Himalayas in the north from the Peninsula in the south.
The Peninsula is a region of relative stability and occasional seismic disturbances.
The river systems of India can be classified into four groups viz.
- The Himalayan rivers are formed by melting snow and glaciers and therefore, continuously flow throughout the year.
- The Deccan rivers on the other hand are rainfed and therefore fluctuate in volume. Many of these are non-perennial.
- The Coastal streams, especially on the west coast are short and have limited catchment areas. Most of them are non-perennial.
- The streams of inland drainage basin of western Rajasthan are few and far apart. Most of them are of an ephemeral character.
The main Himalayan river systems are those of the Indus and the Ganga-Brahmaputra-Meghna system.
In the Deccan region, the major east flowing rivers are Godavari, Krishna, Cauvery and Mahanadi. 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.
The entire country has been divided into 20 river basins/group of river basins comprising 12 major basins and eight composite river basins.
Major River Basins
The 12 major river basins are : (1) Indus, (2) Ganga-Brahmaputra-Meghna, (3) Godavari, (4) Krishna, (5) Cauvery, (6) Mahanadi, (7) Pennar, (8) Brahmani-Baitarani, (9) Sabarmati, (10) Mahi, (11) Narmada and (12) Tapti.
Each of these basins has a drainage area exceeding 20,000 sq. km.
Composite River Basins
The eight composite river basins combining suitably together all the other remaining medium (drainage area of 2,000 to 20,000 sq. km) and small river systems (drainage area less than 2000 sq. km) for the purpose of planning and management are:
Subarnarekha—combining Subarnarekha and other small rivers between Subarnarekha and Baitarani;
- East flowing rivers between Mahanadi and Pennar;
- East flowing rivers between Pennar and Kanyakumari;
- Area of Inland drainage in Rajasthan desert;
- West flowing rivers of Kutch and Saurashtra including Luni;
- West flowing rivers from Tapi to Tadri;
- West flowing rivers from Tadri to Kanyakumari and
- Minor rivers draining into Myanmar (Burma) and Bangladesh
The climate of India may be broadly described as tropical monsoon type.
The Indian Meteorological Department (IMD) designates four official seasons: (i) Winter, (ii) Summer, (iii) Monsoon or rainy season, and (iv) Post-monsoon season.
The Himalayan states, being more temperate, experience two additional seasons: autumn and spring.
Traditionally, Indians note six seasons, each about two months long. These are the spring, summer, monsoon, early autumn, late autumn and winter. These are based on the astronomical division of the 12 months into six parts.
India’s climate is affected by two seasonal winds—the north-east monsoon and the south-west monsoon. The south-west monsoon brings most of the rainfall during the year in the country.
Available data place India in the tenth position in the world and fourth in Asia in plant diversity.
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, the Malabar and the Andaman’s.
The flora of the country is being studied by the Botanical Survey of India (BSI), Kolkata. BSI brings out an inventory of endangered plants in the form of a publication titled ‘Red Data Book.’
According to world biogeographic classification, India represents two of the major realms (the Palearctic and Indo-Malayan) and three biomes (Tropical Humid Forests, Tropical Dry/Deciduous Forests and Warm Deserts/Semi-Deserts).
The Wildlife Institute of India divides the country into ten biogeographic regions: Trans- Himalayan, Himalayan, Indian Desert, Semi-Arid, Western Ghats, Deccan Peninsula, Gangetic Plain, North- East India, Islands and Coasts.
Within only about 2 per cent of world’s total land surface, India is known to have over 7.50 per cent of the species of animals that the world holds.
Census 2011 was the 15th census of its kind since 1872.
The population, which at the turn of the twentieth century was around 238.4 million, increased to reach 1,210.9 million by 2011.
As recorded at each decennial census from 1901 the population has grown steadily except for a decrease during 1911-21.
It is defined as the number of persons per sq. km. The population density of India in 2011 was 382 per sq. km-decadal growth of 17.72 per cent.
Among major states, Bihar is the most thickly populated state with a population density of 1,106 persons per sq. km followed by West Bengal 1,028 and Kerala 860.
- Sex ratio, defined as the number of females per thousand males, was 972 at the beginning of the twentieth century and thereafter showed continuous decline until 1941.
- The sex ratio from 1901-2011 has registered a 10 point increase at census 2011 over 2001; however, child sex ratio has declined to 919 per thousand male.
For the purpose of census 2011, a person aged seven and above, who can both read and write with understanding in any language, is treated as literate. The results of 2011 census reveal that there has been an increase in literacy in the country. The literacy rate in the country is 73.0 per cent, 80.9 for males and 64.6 for females. Kerala retained its position by being on top with a 94 per cent literacy rate, closely followed by Lakshadweep (91.9 per cent). Bihar with a literacy rate of 61.8 per cent ranks last in the country.