Geography of India

2008/9 Schools Wikipedia Selection. Related subjects: Geography of Asia

Geography of India
Continent	Asia
Region	Southern Asia Indian subcontinent
Coordinates	20°00'N 77°00'E
Area	Ranked 7th 3,287,263 km² (1,269,219.3 sq mi) 90.44% land 9.56 % water
Borders	Total land borders: 15,106.70 km (9,387 mi) Bangladesh: 4,096.70 km (2,546 mi) China (PRC): 3,488 km (2,167 mi) Pakistan: 3,323 km (2,065 mi) Nepal: 1,751 km (1,088 mi) Myanmar: 1,643 km (1,021 mi) Bhutan: 699 km (434 mi) Afghanistan: 106 km (66 mi)
Highest point	K2 8,611 m (28,251 ft)
Lowest point	Kuttanad -2.2 m (−7.2 ft)
Longest river	Ganges–Brahmaputra
Largest lake	Chilka Lake

The geography of India is diverse, with landscape ranging from snow-capped mountain ranges to deserts, plains, rainforests, hills, and plateaus. India comprises most of the Indian subcontinent situated on the Indian Plate, the northerly portion of the Indo-Australian Plate. Having a coastline of over 7,000 kilometres (4,350 mi), most of India lies on a peninsula in Southern Asia that protrudes into the Indian Ocean. India is bounded in the southwest by the Arabian Sea and in the east and southeast by the Bay of Bengal.

The fertile Indo-Gangetic Plain occupies most of northern, central, and eastern India, while the Deccan Plateau occupies most of southern India. To the west of the country is the Thar Desert, which consists of a mix of rocky and sandy desert. India's east and northeastern border consists of the high Himalayan range. The highest point in India is disputed owing to a territorial dispute with Pakistan; according to India's claim, the highest point (located in the disputed Kashmir region) is K2, at 8,611 metres (28,251 ft). The highest point in undisputed Indian territory is Kangchenjunga, at 8,598 m (28,209 ft). Climate ranges from equatorial in the far south, to Alpine in the upper reaches of the Himalayas.

India is bordered by Pakistan to the northwest, China, Bhutan and Nepal to the north, Myanmar to the east and Bangladesh to the east of West Bengal. Sri Lanka, the Maldives and Indonesia are island nations to the south of India. Sri Lanka is separated from India by a narrow channel of sea formed by Palk Strait and the Gulf of Mannar.Politically, India is divided into 28 states, and seven federally administered union territories. The political divisions generally follow linguistic and ethnic boundaries rather than geographic transitions.

Location and extent

India lies to the north of the equator between 8°4' and 37°6' north latitude and 68°7' and 97°25' east longitude. It is the seventh-largest country in the world, with a total land area of 3,287,263 square kilometres (1,269,219 sq mi). India measures 3,214 km (1,997 mi) from north to south and 2,993 km (1,860 mi) from east to west. It has a land frontier of 15,200 km (9,445 mi) and a coastline of 7,517 km (4,671 mi).

India is bounded to the southwest by the Arabian Sea, to the southeast by the Bay of Bengal, and the Indian Ocean to the south. To the north, northeast, and northwest are the Himalayas. Cape Comorin constitutes the southern tip of the mainland Indian peninsula, which narrows before ending in the Indian Ocean. The southernmost part of India is Indira Point in the Andaman and Nicobar Islands in the Bay of Bengal. The territorial waters of India extend into the sea to a distance of twelve nautical miles measured from the appropriate baseline.

Political geography

India is divided into 28 states (which are further subdivided into districts), seven union territories. States have their own elected government, while union territories are governed by an administrator appointed by the union government.

States:

Andhra Pradesh Arunachal Pradesh Assam Bihar Chhattisgarh Goa Gujarat Haryana Himachal Pradesh Jammu and Kashmir Jharkhand Karnataka Kerala Madhya Pradesh

Maharashtra Manipur Meghalaya Mizoram Nagaland Orissa Punjab Rajasthan Sikkim Tamil Nadu Tripura Uttar Pradesh Uttarakhand West Bengal

Union Territories: Andaman and Nicobar Islands Chandigarh Dadra and Nagar Haveli Daman and Diu Lakshadweep National Capital Territory of Delhi Puducherry

The state of Jammu and Kashmir is claimed by India and Pakistan, and both administer part of the territory. India also claims Aksai Chin, a small barren piece of territory in Ladakh administered by China. The state of Arunachal Pradesh is claimed by China but administered by India.

Physiographic regions

India is divided into seven physiographic regions. They are

1. The northern mountains including the Himalayas, which includes the Kuen Lun and the Karakoram ranges and the northeast mountain ranges.
2. Indo-Gangetic plains
3. Thar Desert
4. Central Highlands and Deccan Plateau
5. East Coast
6. West Coast
7. Bordering seas and islands

Mountains

A great arc of mountains, composed of the Himalaya, Hindu Kush, and Patkai ranges, define the Indian subcontinent. These mountains were formed by the ongoing tectonic collision of the Indian Plate with the Eurasian Plate which started some 50 million years ago. These mountain ranges are home to some of the world's tallest mountains and act as a natural barrier to cold polar winds. They also facilitate the monsoons winds drive climate in India. Rivers that originate in these mountains provide water to the fertile Indo-Gangetic plains. These mountains are recognised by biogeographers as the boundary between two of the earth's great ecozones; the temperate Palearctic that covers most of Eurasia, and the tropical and subtropical Indomalaya ecozone that includes the Indian subcontinent extending into Southeast Asia and Indonesia. Historically, these ranges have also served as barriers to invaders.

India has nine major mountain ranges having peaks of over 1,000 m (3,281 ft). The Himalayas are the only mountain ranges to have snow-capped peaks. These ranges are:

1. Aravalli Range
2. Eastern Ghats
3. Himalayas
4. Patkai
5. Vindhya Range
6. Western Ghats (Sahyadri)
7. Satpura Range
8. Karakoram
9. Kunlun

The Himalaya mountain range is the world's highest mountain range. They form India's northeastern border, separating it from the rest of Asia. The Himalayas are also one of the world's youngest mountain ranges, and extend almost uninterrupted for a distance of 2,500 m (8,202 ft), covering an area of 500,000 km² (193,051 sq mi). The Himalayas extend from the state of Jammu and Kashmir in the west to the state of Arunachal Pradesh in the east. These states along with Himachal Pradesh, Uttarakhand, and Sikkim lie mostly in the Himalayan region. Some of the Himalayan peaks range over 7,000 m (22,966 ft) and the snow line ranges between 6,000 m (19,685 ft) in Sikkim to around 3,000 m (9,843 ft) in Kashmir. Kangchenjunga, which lies on the Sikkim–Nepal border, is the highest point in the area administered by India. Most peaks in the Himalayas remain snowbound throughout the year.

The Shiwalik, or lower Himalaya, consists of smaller hills towards the Indian side. Most of the rock formations are young and highly unstable, with landslides being a regular phenomenon during the rainy season. Many of India's hill stations are located on this range. The climate varies from subtropical in the foothills to alpine at the higher elevations of these mountain ranges.

The mountains on India's eastern border with Myanmar are called as the Patkai or the Purvanchal. They were created by the same tectonic processes that resulted in the formation of the Himalaya. The features of the Patkai ranges are conical peaks, steep slopes and deep valleys. The Patkai ranges are not as rugged or tall as the Himalayas. There are three hill ranges that come under the Patkai: The Patkai-Bum, the Garo– Khasi– Jaintia, and the Lushai hills. The Garo–Khasi range is in the state of Meghalaya. Mawsynram,a village near Cherrapunji lying on the windward side of these hills, has the distinction of being the wettest place in the world, receiving the highest annual rainfall.

The Vindhya range runs across most of central India, covering a distance of 1,050 km (652 mi). The average elevation of these hills is 3,000 m (9,843 ft). They are believed to have been formed by the wastes created by the weathering of the ancient Aravali mountains. It geographically separates northern India from southern India. The western end of the range lies in eastern Gujarat, near its border with the state of Madhya Pradesh, and the range runs east and north almost meeting the Ganges River at Mirzapur.

The Satpura Range is a range of hills in central India. It begins in eastern Gujarat near the Arabian Sea coast, then runs east across Maharashtra, Madhya Pradesh and ends in the state of Chhattisgarh. It extends for a distance of 900 km (559 mi) with many of its peaks rising above 1,000 m (3,281 ft). It is triangular in shape, with its apex at Ratnapuri and the two sides being parallel to the Tapti and Narmada rivers. It runs parallel to the Vindhya Range, which lies to the north, and these two east-west ranges divide the Indo-Gangetic plain of northern India from the Deccan Plateau lying in the south. The Narmada runs in the depression between the Satpura and Vindhya ranges, and drains the northern slope of the Satpura range, running west towards the Arabian Sea.

The Aravali Range is the oldest mountain range in India, running from northeast to southwest across Rajasthan in western India, extending approximately 500 km (311 mi). The northern end of the range continues as isolated hills and rocky ridges into Haryana, ending near Delhi. The highest peak is Mount Abu, rising to 1,722 m (5,650 ft), lying near the southwestern extremity of the range, close to the border with Gujarat. The Aravali Range is the eroded stub of an ancient folded mountain system that was once snow-capped. The range rose in a Precambrian event called the Aravali-Delhi orogen. The range joins two of the ancient segments that make up the Indian craton, the Marwar segment to the northwest of the range, and the Bundelkhand segment to the southeast.

The Western Ghats or Sahyadri mountains run along the western edge of India's Deccan Plateau, and separate it from a narrow coastal plain along the Arabian Sea. The range starts south of the Tapti River near the Gujarat–Maharashtra border, and runs approximately 1,600 km (994 mi) across the states of Maharashtra, Goa, Karnataka, Kerala, and Tamil Nadu, almost to the southern tip of the Indian peninsula. The average elevation is around 1,000 m (3,281 ft). The Anai Mudi in the Anaimalai Hills at 2,695 m (8,842 ft)in Kerala is the highest peak in the Western Ghats.

The Eastern Ghats are a discontinuous range of mountains, which have been eroded and cut through by the four major rivers of southern India, the Godavari, Mahanadi, Krishna, and Kaveri. These mountain ranges extend from West Bengal in the north, through Orissa and Andhra Pradesh to Tamil Nadu in the south. They run parallel to the Bay of Bengal. Though not as tall as the Western Ghats, though some of its peaks are over 1,000 m (3,281 ft) in height. The Eastern Ghats meet with the Western Ghats meet at the Nilgiri hills in Tamil Nadu.

Indo-Gangetic plain

Extent of the Indo-Gangetic plain across South Asia.

The Indo-Gangetic plains are large floodplains of the Indus and the Ganga-Brahmaputra river systems. They run parallel to the Himalaya mountains, from Jammu and Kashmir in the west to Assam in the east, draining the states of Punjab, Haryana, parts of Rajasthan, Uttar Pradesh, Bihar, Jharkhand and West Bengal. The plains encompass an area of 700,000 km² (270,000 mile²) and vary in width through their length by several hundred kilometres. Major rivers that form a part of this system are the Ganga (Ganges) and Indus River along with their tributaries; Beas, Yamuna, Gomti, Ravi, Chambal, Sutlej and Chenab.
The great plains are sometimes classified into four divisions:

• The Bhabar belt- This is adjacent to the foothills of the Himalayas and consists of boulders and pebbles which have been carried down by the river streams. As the porosity of this belt is very high, the streams flow underground. The bhabar is generally narrow about 7-15 km wide.
• The Terai belt- This belt lies next to the Bhabar region and is composed of newer alluvium. The underground streams reappear in this region. The region is excessively moist and thickly forested. It also receives heavy rainfall throughout the year and is populated with a variety of wildlife.
• The Bangar belt- It consists of older alluvium and forms the alluvial terrace of the flood plains. In the Gangetic plains, it has a low upland covered by laterite deposits.
• The Khadar belt- It lies in lowland areas after the Bangar belt. It is made up of fresh newer alluvium which is deposited by the rivers flowing down the plain.

The Indo-Gangetic belt is the world's most extensive expanse of uninterrupted alluvium formed by the deposition of silt by the numerous rivers. The plains are flat and mostly treeless, making it conducive for irrigation through canals. The area is also rich in ground water sources.

The plains are one of the world's most intensely farmed areas. Crops grown on the Indo-Gangetic Plain are primarily rice and wheat, grown in rotation. Other crops include maize, sugarcane and cotton. Also known as the Great Plains, the Indo-Gangetic plains rank among the world's most densely populated areas.

The Desert

The Thar Desert (also known as the Great Indian Desert) is a hot desert that forms a significant portion of western India. Spread over four states in India— Punjab, Haryana, Rajasthan, and Gujarat it covers an area of 208,110 km² (80,350 mile²). The desert continues into Pakistan as the Cholistan Desert. Most of the Thar Desert is situated in Rajasthan, covering 61% of its geographic area. Most of the desert is rocky, with a small part of the extreme west of the desert being sandy.

The origin of the Thar Desert is uncertain. Some geologists consider it to be 4,000 to 10,000 years old, whereas others state that aridity began in this region much earlier. The area is characterised by extreme temperatures of above 45 ° C (113 ° F) in summer to below freezing in winters. Rainfall is precarious and erratic, ranging from below 120 mm (4.72 inches) in the extreme west to 375 mm (14.75 inches) eastward. The lack of rainfall is mainly due to the unique position of the desert with respect to the Aravalli range. The desert lies in the rain shadow area of the Bay of Bengal arm of the southwest monsoon. The parallel nature of the range to the Arabian Sea arm also means that the desert does not receive much rainfall.

The soils of the arid region are generally sandy to sandy-loam in texture. The consistency and depth vary according to the topographical features. The low-lying loams are heavier and may have a hard pan of clay, calcium carbonate or gypsum. Because of the low population density, the effect of the population on the environment is relatively less compared to the rest of India.

Highlands

The Central Highlands are composed of three main plateaus—the Malwa Plateau in the west, the Deccan Plateau in the south, (covering most of the Indian peninsula), and the Chota Nagpur Plateau in Jharkhand towards the east.

The Deccan Plateau is a large triangular plateau, bounded by the Vindhyas to the north and flanked by the Eastern and Western Ghats. The Deccan covers a total area of 1.9 million km² (735,000 mile²). It is mostly flat, with elevations ranging from 300 to 600 m (1,000 to 2,000 ft).

The name Deccan comes from the Sanskrit word dakshina, which means "the south". The plateau slopes gently from west to east and gives rise to several peninsular rivers such as the Godavari, the Krishna, the Kaveri and the Narmada. This region is mostly semi-arid as it lies on the leeward side of both Ghats. Much of the Deccan is covered by thorn scrub forest scattered with small regions of deciduous broadleaf forest. Climate ranges from hot summers to mild winters.

The Chota Nagpur Plateau is a plateau in eastern India, which covers much of Jharkhand state as well as adjacent parts of Orissa, Bihar, and Chhattisgarh. The total area of Chota Nagpur Plateau is approximately 65,000 km² (25,000 mile²). The Chota Nagpur Plateau is made up of three smaller plateaus, the Ranchi, Hazaribagh, and Kodarma plateaus. The Ranchi plateau is the largest of the plateaus, with an average elevation of 700 m (2,300 ft). Much of the plateau is forested, covered by the Chota Nagpur dry deciduous forests. The plateau is famous for its vast reserves of ores and coal.

Besides the Great Indian peninsula, the Kathiawar Peninsula in Gujarat is another large peninsula of India.

East coast

The Eastern Coastal Plain is a wide stretch of land lying between the Eastern Ghats and the Bay of Bengal. It stretches from Tamil Nadu in the south to West Bengal in the north. Deltas of many of India's rivers form a major portion of these plains. The Mahanadi, Godavari, Kaveri and Krishna rivers drain these plains. The region receives both the Northeast and Southwest monsoon rains with its annual rainfall averaging between 1,000 mm (40 in) and 3,000 mm (120 in). The width of the plains varies between 100 to 130 km (62 to 80 miles).

The plains are divided into six regions: The Mahanadi delta; the southern Andhra Pradesh plain; the Krishna Godavari deltas; the Kanyakumari coast; Coromandel Coast and sandy coastal.

West coast

The Western Coastal Plain is a narrow strip of land sandwiched between the Western Ghats and the Arabian Sea. The strip begins in Gujarat in the north and extends across the states of Maharashtra, Goa, Karnataka and Kerala. The plains are narrow, and range from 50 to 100 km (30 to 60 miles) in width.

Small rivers and numerous backwaters inundate the region. The rivers, which originate in the Western Ghats, are fast flowing and are mostly perennial. The fast flowing nature of the rivers results in the formation of estuaries rather than deltas. Major rivers flowing into the sea are the Tapi, Narmada, Mandovi and Zuari.

The coast is divided into three regions. The northern region of Maharashtra and Goa is known as the Konkan Coast, the central region of Karnataka is known as the Kanara Coast and the southern coastline of Kerala is known as the Malabar Coast. Vegetation in this region is mostly deciduous. The Malabar Coast has its own unique ecoregion known as the Malabar Coast moist forests.

Islands

India has two major offshore island possessions: the Lakshadweep islands and the Andaman and Nicobar Islands. Both these island groups are administered by the Union government of India as Union Territories.

The Lakshadweep islands lie 200 to 300 km (124 to 186 miles) off the coast of Kerala in the Arabian Sea. It consists of twelve coral atolls, three coral reefs, and five banks. Ten of these islands are inhabited.

The Andaman & Nicobar Islands are located between 6^o and 14^o North latitude and 92^o and 94^o East longitude. The Andaman and Nicobar islands consist of 572 isles which lie in the Bay of Bengal, near the Myanmar coast. It is located 1255 km (780 miles) from Kolkata (Calcutta) and 193 km (120 miles) from Cape Negrais in Myanmar. The territory consists of two island groups, the Andaman Islands and the Nicobar Islands. The Andaman islands consist of 204 islands having a total length of 352 km (220 miles). The Nicobar Islands, which lie south of the Andamans, consist of twenty-two islands with a total area of 1,841 km² (710 mile²). The highest point is Mount Thullier at 642 m (2,140 ft). Indira Point, India's southernmost land point is situated in the Nicobar islands, and lies just 189 km (117 miles) from the Indonesian island of Sumatra to the southeast.

Significant islands just off the Indian coast include Diu, a former Portuguese enclave; Majuli, Asia's largest freshwater island; Salcette Island, India's most populous island, on which Mumbai (Bombay) city is located; Elephanta in Bombay Harbour; and Sriharikota barrier island in Andhra Pradesh.

Rivers

All major rivers of India originate from one of the three main watersheds. They are:

1. The Himalaya and the Karakoram ranges
2. Vindhya and Satpura range in central India
3. Sahyadri or Western Ghats in western India

The Himalayan river networks are snow-fed and have a continuous flow throughout the year. The other two networks are dependent on the monsoons and shrink into rivulets during the dry season.

Twelve of India's rivers are classified as major, with the total catchment area exceeding 2,528,000 km² (976,000 mile²).

Himalayan rivers or the northern rivers that flow westward into Pakistan are the Indus, Beas, Chenab, Ravi, Sutlej, and Jhelum.

The Ganga-Brahmaputra-Meghana system has the largest catchment area of 1,100,000 km² (424,700 mile²). The river Ganga originates at the Gangotri Glacier in Uttarakhand. It flows in a south easterly direction, draining into Bangladesh. The Yamuna and Gomti rivers also arise in the Western Himalayas and join the Ganga river in the plains. The Brahmaputra, another tributary of the Ganga originates in Tibet and enters India in the far eastern state of Arunachal Pradesh. It then proceeds westwards, unifying with the Ganga in Bangladesh.

The Chambal, another tributary of the Ganga originates from the Vindhya-Satpura watershed. The river flows eastward. Westward flowing rivers from this watershed are the Narmada (also called Nerbudda) and Tapti (also spelled Tapi) rivers which drain into the Arabian Sea in Gujarat. The river network that flows from east to west constitutes 10% of the total outflow.

The Western Ghats are the source of all Deccan rivers. Major rivers in the Deccan include the Mahanadi River through the Mahanadi River Delta, Godavari River, Krishna River, and Kaveri River (also spelled Cauvery), all draining into the Bay of Bengal. These rivers constitute 20% of India's total outflow.

Bodies of water

Major gulfs include the Gulf of Cambay, Gulf of Kutch and the Gulf of Mannar. Straits include the Palk Strait which separates India from Sri Lanka and the Ten Degree Channel, separating the Andamans from the Nicobar Islands and the Eight Degree Channel separating the Laccadive and Amindivi Islands from Minicoy Island towards the south. Important capes include the Cape Comorin, the southern tip of mainland India, Indira Point, the southernmost location of India, Rama's Bridge and Point Calimere. Arabian Sea is to the west of India. Bay of Bengal is to the eastern side of India while India Ocean is to the South of India.

Smaller seas include the Laccadive Sea and the Andaman Sea. There are four coral reefs in India and are located in; the Andaman and Nicobar Islands, Gulf of Mannar, Lakshadweep and Gulf of Kutch.

Important lakes include Chilka Lake, the country's largest saltwater lake in Orissa; Kolleru Lake in Andhra Pradesh; Loktak Lake in Manipur, Dal Lake in Kashmir, Sambhar Lake in Rajasthan, and the Sasthamkotta Lake in Kerala.

Wetlands

Wetlands are lands transitional between aquatic and territorial system where water table is usually near the water surface and land is covered by shallow water. They also act as a buffer against the devastating effect of hurricanes and cyclones, thereby stabilizing the shoreline. It also helps in keeping a check on sea and soil erosion. India's wetland ecosystem is widely distributed from the cold and arid; from ones in the Ladakh region in the state of Jammu and Kashmir to the ones in the wet and humid climate of peninsula India. Most of the wetlands are directly or indirectly linked to India's river networks. In 1987, National Wetland Conservation Programme was initiated by the government for wetland conservation. Under this programme, the Indian government has identified a total of 71 wetlands for conservation.

Mangrove forests occur all along the Indian coastline, in sheltered estuaries, creeks, backwaters, salt marshes and mudflats. The mangrove area covers a total of 4 461 km² (1,722 mile²) which comprises 7% of the world's total mangrove cover. The Andaman and Nicobar Islands; the Sundarbans; Gulf of Kutch; deltas of the Mahanadi, Godavari and Krishna; and parts of Maharashtra, Karnataka and Kerala have large mangrove covers. Most of the identified wetlands adjoin or are parts of sanctuaries, national parks and are thus protected.

The Sundarbans

The Sundarbans delta is the largest mangrove forest in the world. It lies at the mouth of the Ganges and is spread across areas of Bangladesh and West Bengal, India. The Bangladeshi and Indian portions of the jungle are listed in the UNESCO world heritage list separately as the Sundarbans and Sundarbans National Park respectively, though they are parts of the same forest. The Sundarbans are intersected by a complex network of tidal waterways, mudflats and small islands of salt-tolerant mangrove forests, and presents an excellent example of ongoing ecological processes.

The area is known for its wide range of fauna. The most famous among these is the Bengal Tiger, but numerous species of birds, spotted deer, crocodiles and snakes also inhabit it. It is estimated that there are now 400 Bengal tigers and about 30,000 spotted deer in the area.

Rann of Kutch

The Rann of Kutch is a marshy region located in the Gujarat state of India, which borders the Sindh region of Pakistan. The name Rann comes from the Hindi word ran meaning "salt marsh." It occupies a total area of 27 900 km² (10,800 mile²).

The region was originally a part of the Arabian Sea. Geologic forces, most likely by earthquakes, resulted in the damming up of the region, turning it into a large saltwater lagoon. This area gradually filled with silt thus turning it into a seasonal salt marsh. During the monsoons, the area turns into a shallow marsh, often flooding to knee-depth. After the monsoons, the region turns dry and becomes parched.

Soil

Soils in India can be classified into 8 categories namely, alluvial soil, black soil, red soil, laterite soil, forest soil, arid & desert soil, saline & alkaline soil, and finally peaty & organic soil. Of the above eight varieties, the first 4 constitute nearly 80% of total land surface. Alluvial soil constitute the largest soil group in India. It is derived from deposition of silt carried by numerous rivers. Alluvial soils are generally fertile but they lack nitrogen and tend to be phosphoric. These are found in the Great Northern plains from Punjab to Assam valley.

Black soil are well developed in the Deccan lava region of Maharashtra, Gujarat, and Madhya Pradesh. These contain high percentage of clay and are thus moisture retentive. Because of these properties they are preferred for dry farming and growing cotton, linseed etc.

Red soil have a wide diffusion of iron content and are found in Tamil Nadu, Karnataka plateau, and Andhra plateau. The central highlands from Aravallis to Chota Nagpur plateau also have significant tracts of red soil. These are deficient in nitrogen, phosphorus and humus.

Laterite soils are formed in tropical regions with heavy rainfall. Heavy rainfall results in leaching out all soluble material of top layer of soil. These are generally found in Western ghats, Eastern ghats and hilly areas of northeastern states which receive very heavy rainfall.

Forest soils occur on the slopes of mountains and hills in Himalayas, Western Ghats and Eastern Ghats. These generally consist of large amounts of dead leaves and other organic matter called humus. These soils are used for tea and coffee plantations.

Climate

The climate of India is comprised of a wide range of weather conditions across a vast geographic scale and varied topography, making generalisations difficult. Based on the Köppen system, India hosts six major climatic subtypes, ranging from arid desert in the west, alpine tundra and glaciers in the north, and humid tropical regions supporting rainforests in the southwest and the island territories. Many regions have starkly different microclimates. The nation has four seasons: winter (January–February), summer (March–May), a monsoon (rainy) season (June–September), and a post-monsoon period (October–December).

India's unique geography and geology strongly influence its climate; this is particularly true of the Himalayas in the north and the Thar Desert in the northwest. The Himalayas act as a barrier to the frigid katabatic winds flowing down from Central Asia. Thus, North India is kept warm or only mildly cooled during winter; in summer, the same phenomenon makes India relatively hot. Although the Tropic of Cancer—the boundary between the tropics and subtropics—passes through the middle of India, the whole country is considered to be tropical.

Summer lasts between March and June in most parts of India. Temperatures exceed 40 °C (104 °F) during the day. The coastal regions exceed 30 °C (86 °F) coupled with high levels of humidity. In the Thar desert area temperatures can exceed 45 °C (113 °F).

Summer is followed by the southwest monsoon rains that provide most of India with its rainfall. The rain-bearing clouds are attracted to the low-pressure system created by the Thar Desert. The official date for the arrival of the monsoon is 1 June, when the monsoon crosses the Kerala coast. The southwest monsoon splits into two arms, the Bay of Bengal arm and the Arabian Sea arm. The Bay of Bengal arm moves northwards crossing northeast India in early June. It then progresses eastwards, crossing Delhi by June 29. The Arabian Sea arm moves northwards and deposits much of its rain on the windward side of Western Ghats. By early July, most of India receives rain from the monsoons.

The monsoons start retreating by August from northern India and by October from Kerala. This short period after the retreat is known as the retreat of the monsoons and is characterised by still weather. By November, winter starts setting in the northern areas.

Winters start in November in northern India and late December in southern India. Winters in peninsula India see mild to warm days and cool nights. Further north the temperature is cooler. Temperatures in some parts of the Indian plains sometimes fall below freezing. Most of northern India is plagued by fog during this season.

The highest temperature recorded in India was 50.6 °C (123.08 °F) in Alwar in 1955. The lowest was −45 °C (−49 °F) in Kashmir. Recent claims of temperatures touching 55 °C (131 °F) in Orissa have been met with some scepticism by the Indian Meteorological Department, largely on the method of recording of such data.

Geology

India has a varied geology spanning the entire spectrum of the geological time period. India's geological features are classified based on their era of formation.

The Precambrian formations of Cudappah and Vindhyan systems are spread out over the eastern and southern states. A small part of this period is spread over western and central India.

The Paleozoic formations from the Cambrian, Ordovician, Silurian and Devonian system are found in the Western Himalaya region in Kashmir and Himachal Pradesh.

The Mesozoic Deccan Traps formation is seen over most of the northern Deccan. Geologists believe that the Deccan Traps were the result of sub-aerial volcanic activity. The Trap soil is black in colour and conducive to agriculture. The Carboniferous system, Permian System, Triassic and Jurassic systems are seen in the western Himalayas. The Jurassic system is also seen in Rajasthan.

Tertiary imprints are seen in parts of Manipur, Nagaland, parts of Arunachal Pradesh and along the Himalayan belt. The Cretaceous system is seen in central India in the Vindhyas and part of the Indo-Gangetic plains.

The Gondowana system is also seen in the Narmada River area in the Vindhyas and Satpuras. The Eocene system is seen in the western Himalayas and Assam. Oligocene formations are seen in Kutch and in Assam.

The Pleistocene system is found over central India. It is rich in minerals such as lignite, iron ore, manganese, and aluminium. The Andaman and Nicobar Island groups are thought to have been formed in this era by volcanoes.

The Himalayas are a result of the convergence and deformation of the Indo-Australian and Eurasian Plates. Their continued convergence raises the height of the Himalayas by 1 cm each year.

Natural disasters

Natural disasters cause massive losses of Indian life and property. Droughts, flash floods, cyclones, avalanches, landslides brought on by torrential rains, and snowstorms pose the greatest threats. Other dangers include frequent summer dust storms, which usually track from north to south; they cause extensive property damage in North India and deposit large amounts of dust from arid regions. Hail is also common in parts of India, causing severe damage to standing crops such as rice and wheat

In the Lower Himalaya, landslides are common. The young age of the region's hills result in labile rock formations, which are susceptible to slippages. Parts of the Western Ghats also suffer from low-intensity landslides. Avalanches occur in Kashmir, Himachal Pradesh, and Sikkim. Floods are the most common natural disaster in India. The heavy southwest monsoon rains cause the Brahmaputra and other rivers to distend their banks, often flooding surrounding areas. Though they provide rice paddy farmers with a largely dependable source of natural irrigation and fertilisation, the floods can kill thousands and displace millions. Excess, erratic, or untimely monsoon rainfall may also wash away or otherwise ruin crops. Almost all of India is flood-prone, and extreme precipitation events, such as flash floods and torrential rains, have become increasingly common in central India over the past several decades, coinciding with rising temperatures. Mean annual precipitation totals have remained steady owing to the declining frequency of weather systems that generate moderate amounts of rain.

Indian agriculture is heavily dependent on the monsoon as a source of water. In some parts of India, the failure of the monsoons result in water shortages, resulting in below-average crop yields. This is particularly true of major drought-prone regions such as southern and eastern Maharashtra, northern Karnataka, Andhra Pradesh, Orissa, Gujarat, and Rajasthan. In the past, droughts have periodically led to major Indian famines, including the Bengal famine of 1770, in which up to one third of the population in affected areas died; the 1876–1877 famine, in which over five million people died; the 1899 famine, in which over 4.5 million died; and the Bengal famine of 1943, in which over five million died from starvation and famine-related illnesses.

According to earthquake hazard zoning of India, tectonic plates beneath the earth's surface are responsible for yearly earthquakes along the Himalayan belt and in northeast India. This region is classified as a Zone V, indicating that it is a very high-risk area. Parts of western India, around the Kutch region in Gujarat and Koyna in Maharashtra, are classified as a Zone IV region (high risk). Other areas have a moderate to low risk chance of an earthquake occurring.

Tropical cyclones, which are severe storms spun off from the Intertropical Convergence Zone, may affect thousands of Indians living in coastal regions. Cyclones bring with them heavy rains, storm surges, and winds that often cut affected areas off from relief and supplies. In the North Indian Ocean Basin, the cyclone season runs from April to December, with peak activity between May and November. Each year, an average of eight storms with sustained wind speeds greater than 63  kilometres per hour (39  mph) form; of these, two strengthen into true tropical cyclones, which have sustained gusts greater than 117 km/h (73 mph). On average, a major ( Category 3 or higher) cyclone develops every other year. In terms of damage and loss of life, Cyclone 05B, a supercyclone that struck Orissa on 29 October 1999, was the worst in more than a quarter century.

A tsunami caused by the 2004 Indian Ocean earthquake struck the Andaman and Nicobar Islands and India's east coast resulting in the deaths of an estimated 10,000. Until then India was thought to have negligible activity related to tsunamis, though there is historical anecdotal evidence of its occurrence in the past.

India has one active volcano: the Barren Island volcano which last erupted in May 2005. There is also a dormant volcano called the Narcondum and a mud volcano at Baratang. All these volcanoes lie in the Andaman Islands.

International agreements

India is a party to several International agreements related to environment and climate, the most prominent among them are:

Treaties and Agreements
Specific Regions and Seas	The Antarctic Treaty, Law of the Sea, Ship Pollution ( MARPOL 73/78), Whaling
Atmosphere and Climate	Climate Change, Kyoto Protocol, Ozone Layer Protection, Nuclear Test Ban
Biodiversity, Environment and Forests	Desertification, Endangered Species, Environmental Modification, Tropical Timber 83 and Tropical Timber 94, Wetlands
Wastes	Hazardous Wastes
Rivers	Indus Waters Treaty