INDIA IS A COUNTRY of great diversity with a wide range of landform types, including major mountain ranges, deserts, rich agricultural plains, and hilly jungle regions. Indeed, the term Indian subcontinent aptly describes the enormous extent of the earth's surface that India occupies, and any attempt to generalize about its physiography is inaccurate. Diversity is also evident in the geographical distribution of India's ethnic and linguistic groups. In ancient times, the major river valleys of the Indo-Gangetic Plain of South Asia were among the great cradles of civilization in Asia, as were the valleys of the Tigris and Euphrates rivers in West Asia and the Huang He (Yellow River) in East Asia. As a result of thousands of years of cultural and political expansion and amalgamation, contemporary India has come to include many different natural and cultural regions.
The Himalayas (and the nations of Nepal and Bhutan) form India's northern frontier with China. Pakistan borders India to the west and Bangladesh (formerly East Pakistan) to the east. Although both were formerly part of the British Indian Empire, India and Pakistan became separate countries in 1947 and East Pakistan became independent Bangladesh in 1971. The boundaries of the Indian polity are not fully demarcated because of regional ethnic and political disputes and are the source of occasional tensions.
When the 1991 national census was taken, India's population was approximately 846.3 million. The annual population growth rate from 1981 to 1991 was 2 percent. Accounting for only 2.4 percent of the world's landmass, India is home to 16 percent of the world's population. Every sixth person in the world in the early 1990s was an Indian. It is generally assumed that India's population will surpass the 1 billion mark some time before the next census in 2001. In July 1995, the population was estimated at 936.5 million.
Some 38 percent of all Indians were officially listed as living below the poverty line in fiscal year (FY--see Glossary) 1991. This number represented an increase from the low mark of 26 percent in FY 1989, but the rise was believed to be only temporary by some observers. Although government-sponsored health clinics are widely available in the mid-1990s, their emphasis is on curative techniques rather than preventive medicine. However, the lack of such basic amenities as safe, potable water for much of the population is indicative of the severity of health problems. This situation has traditionally led most Indians to have large families as their only form of insurance against sickness and for their care in old age. Although family planning programs are becoming integrated with the programs of urban and rural health clinics, no official birth control programs have widespread support. The severity of the acquired immune deficiency syndrome (AIDS) epidemic in India has become increasingly apparent to health specialists, but local awareness of the causes of and ways to prevent the spread of AIDS is growing slowly.
Although many public schools are inadequate, improvements to the education system overall have been substantial since 1947. In the mid-1990s, however, only about 50 percent of children between the ages of six and fourteen are enrolled in schools. The goal of compulsory and free primary and middle school education is embodied in the Indian constitution but has been elusive. The National Policy on Education of 1986 sought to institutionalize universal primary education by setting 1990 as a target date for the education of all children up to eleven years of age. The ability of India's education system to meet this goal has been constrained by lack of adequate financial resources. Important achievements have been made, however, with implementation of the nonformal education system and adult education programs. Whereas public education is generally below standard, education standards in private schools are very high. There also are high standards among the elite institutions in the higher education system.
India's total land mass is 2,973,190 square kilometers and is divided into three main geological regions: the Indo-Gangetic Plain, the Himalayas, and the Peninsula region (see fig. 5). The Indo-Gangetic Plain and those portions of the Himalayas within India are collectively known as North India. South India consists of the peninsular region, often termed simply the Peninsula. On the basis of its physiography, India is divided into ten regions: the Indo-Gangetic Plain, the northern mountains of the Himalayas, the Central Highlands, the Deccan or Peninsular Plateau, the East Coast (Coromandel Coast in the south), the West Coast (Konkan, Kankara, and Malabar coasts), the Great Indian Desert (a geographic feature known as the Thar Desert in Pakistan) and the Rann of Kutch, the valley of the Brahmaputra in Assam, the northeastern hill ranges surrounding the Assam Valley, and the islands of the Arabian Sea and the Bay of Bengal.
In social and economic terms, the Indo-Gangetic Plain is the most important region of India. The plain is a great alluvial crescent stretching from the Indus River system in Pakistan to the Punjab Plain (in both Pakistan and India) and the Haryana Plain to the delta of the Ganga (or Ganges) in Bangladesh (where it is called the Padma). Topographically the plain is homogeneous, with only floodplain bluffs and other related features of river erosion and changes in river channels forming important natural features.
Two narrow terrain belts, collectively known as the Terai, constitute the northern boundary of the Indo-Gangetic Plain. Where the foothills of the Himalayas encounter the plain, small hills known locally as ghar (meaning house in Hindi) have been formed by coarse sands and pebbles deposited by mountain streams. Groundwater from these areas flows on the surface where the plains begin and converts large areas along the rivers into swamps. The southern boundary of the plain begins along the edge of the Great Indian Desert in the state of Rajasthan and continues east along the base of the hills of the Central Highlands to the Bay of Bengal (see fig. 1). The hills, varying in elevation from 300 to 1,200 meters, lie on a general east-west axis. The Central Highlands are divided into northern and southern parts. The northern part is centered on the Aravalli Range of eastern Rajasthan. In the northern part of the state of Madhya Pradesh, the Malwa Plateau comprises the southern part of the Central Highlands and merges with the Vindhya Range to the south. The main rivers that flow through the southern part of the plain--the Narmada, the Tapti, and the Mahanadi--delineate North India from South India (see Rivers, this ch.).
Some geographers subdivide the Indo-Gangetic Plain into three parts: the Indus Valley (mostly in Pakistan), the Punjab (divided between India and Pakistan) and Haryana plains, and the middle and lower Ganga. These regional distinctions are based primarily on the availability of water. By another definition, the Indo-Gangetic Plain is divided into two drainage basins by the Delhi Ridge; the western part consists of the Punjab Plain and the Haryana Plain, and the eastern part consists of the Ganga-Brahmaputra drainage systems. This divide is only 300 meters above sea level, contributing to the perception that the Indo-Gangetic Plain appears to be continuous between the two drainage basins. The Punjab Plain is centered in the land between five rivers: the Jhelum, the Chenab, the Ravi, the Beas, and the Sutlej. (The name Punjab comes from the Sanskrit pancha ab , meaning five waters or rivers.)
Both the Punjab and Haryana plains are irrigated with water from the Ravi, Beas, and Sutlej rivers. The irrigation projects emanating from these rivers have led to a decrease in the flow of water reaching the lower drainage areas in the state of Punjab in India and the Indus Valley in Pakistan. The benefits that increased irrigation has brought to farmers in the state of Haryana are controversial in light of the effects that irrigation has had on agricultural life in the Punjab areas of both India and Pakistan.
The middle Ganga extends from the Yamuna River in the west to the state of West Bengal in the east. The lower Ganga and the Assam Valley are more lush and verdant than the middle Ganga. The lower Ganga is centered in West Bengal from which it flows into Bangladesh and, after joining the Jamuna (as the lower reaches of the Brahmaputra are known in Bangladesh), forms the delta of the Ganga. The Brahmaputra (meaning son of Brahma) rises in Tibet (China's Xizang Autonomous Region) as the Yarlung Zangbo River, flows through Arunachal Pradesh and Assam, and then crosses into Bangladesh. Average annual rainfall increases moving west to east from approximately 600 millimeters in the Punjab Plain to 1,500 millimeters around the lower Ganga and Brahmaputra.
The Himalayas, the highest mountain range in the world, extend along the northern frontiers of Pakistan, India, Nepal, Bhutan, and Burma. They were formed geologically as a result of the collision of the Indian subcontinent with Asia. This process of plate tectonics is ongoing, and the gradual northward drift of the Indian subcontinent still causes earthquakes (see Earthquakes, this ch.). Lesser ranges jut southward from the main body of the Himalayas at both the eastern and western ends. The Himalayan system, about 2,400 kilometers in length and varying in width from 240 to 330 kilometers, is made up of three parallel ranges--the Greater Himalayas, the Lesser Himalayas, and the Outer Himalayas--sometimes collectively called the Great Himalayan Range. The Greater Himalayas, or northern range, average approximately 6,000 meters in height and contain the three highest mountains on earth: Mount Everest (8,796 meters) on the China-Nepal border; K2 (8,611 meters, also known as Mount Godwin-Austen, and in China as Qogir Feng) in an area claimed by India, Pakistan, and China; and Kanchenjunga (8,598 meters) on the India-Nepal border. Many major mountains are located entirely within India, such as Nanda Devi (7,817 meters) in the state of Uttar Pradesh. The snow line averages 4,500 to 6,000 meters on the southern side of the Greater Himalayas and 5,500 to 6,000 on the northern side. Because of climatic conditions, the snow line in the eastern Himalayas averages 4,300 meters, while in the western Himalayas it averages 5,800 meters.
The Lesser Himalayas, located in northwestern India in the states of Himachal Pradesh and Uttar Pradesh, in north-central India in the state of Sikkim, and in northeastern India in the state of Arunachal Pradesh, range from 1,500 to 5,000 meters in height. Located in the Lesser Himalayas are the hill stations of Shimla (Simla) and Darjiling (Darjeeling). During the colonial period, these and other hill stations were used by the British as summer retreats to escape the intense heat of the plains. It is in this transitional vegetation zone that the contrasts between the bare southern slopes and the forested northern slopes become most noticeable.
The Outer or Southern Himalayas, averaging 900 to 1,200 meters in elevation, lie between the Lesser Himalayas and the Indo-Gangetic Plain. In Himachal Pradesh and Uttar Pradesh, this southernmost range is often referred to as the Siwalik Hills. It is possible to identify a fourth, and northernmost range, known as the Trans-Himalaya. This range is located entirely on the Qinghai-Xizang Plateau, north of the great west-to-east trending valley of the Yarlung Zangbo River. Although the Trans-Himalaya Range is divided from the Great Himalayan Range for most of its length, it merges with the Great Himalayan Range in the western section--the Karakoram Range--where India, Pakistan, and China meet.
The southern slopes of each of the Himalayan ranges are too steep to accumulate snow or support much tree life; the northern slopes generally are forested below the snow line. Between the ranges are extensive high plateaus, deep gorges, and fertile valleys, such as the vales of Kashmir and Kulu. The Himalayas serve a very important purpose. They provide a physical screen within which the monsoon system operates and are the source of the great river systems that water the alluvial plains below (see Climate, this ch.). As a result of erosion, the rivers coming from the mountains carry vast quantities of silt that enrich the plains.
The area of northeastern India adjacent to Burma and Bangladesh consists of numerous hill tracts, averaging between 1,000 and 2,000 meters in elevation, that are not associated with the eastern part of the Himalayas in Arunachal Pradesh. The Naga Hills, rising to heights of more than 3,000 meters, form the watershed between India and Burma. The Mizo Hills are the southern part of the northeastern ranges in India. The Garo, Khasi, and Jaintia hills are centered in the state of Meghalaya and, isolated from the northeastern ranges, divide the Assam Valley from Bangladesh to the south and west.
The Peninsula proper is an old, geologically stable region with an average elevation between 300 and 1,800 meters. The Vindhya Range constitutes the main dividing line between the geological regions of the Indo-Gangetic Plain and the Peninsula. This range lies north of the Narmada River, and when viewed from there, it is possible to discern the prominent escarpments that rise between 800 and 1,400 meters. The Vindhya Range defines the north-central and northwestern boundary of the Peninsula, and the Chota Nagpur Plateau of southern Bihar forms the northeastern boundary. The uplifting of the plateau of the central Peninsula and its eastward tilt formed the Western Ghats, a line of hills running from the Tapti River south to the tip of the Peninsula. The Eastern Ghats mark the eastern end of the plateau; they begin in the hills of the Mahanadi River basin and converge with the Western Ghats at the Peninsula's southern tip.
The interior of the Peninsula, south of the Narmada River, often termed the Deccan Plateau or simply the Deccan (from the Sanskrit daksina , meaning south), is a series of plateaus topped by rolling hills and intersected by many rivers. The plateau averages roughly 300 to 750 meters in elevation. Its major rivers--the Godavari, the Krishna, and the Kaveri--rise in the Western Ghats and flow eastward into the Bay of Bengal.
The coastal plain borders the plateau. On the northwestern side, it is characterized by tidal marshes, drowned valleys, and estuaries; and in the south by lagoons, marshes, and beach ridges. Coastal plains on the eastern side are wider than those in the west; they are focused on large river deltas that serve as the centers of human settlement.
India's offshore islands, constituting roughly one-quarter of 1 percent of the nation's territory, lie in two groups located off the east and west coasts. The northernmost point of the union territory of the Andaman and Nicobar Islands lies 1,100 kilometers southeast of Calcutta. Situated in the Bay of Bengal in a chain stretching some 800 kilometers, the Andaman Islands comprise 204 islands and islets, and their topography is characterized by hills and narrow valleys. Although their location is tropical, the climate of the islands is tempered by sea breezes; rainfall is irregular. The Nicobar Islands, which are south of the Andaman Islands, comprise nineteen islands, some with flat, coral-covered surfaces and others with hills. The islands have a nearly equatorial climate, heavy rainfall, and high temperatures. The union territory of Lakshadweep (the name means 100,000 islands) in the Arabian Sea, comprises--from north to south--the Amindivi, Laccadive, Cannanore, and Minicoy islands. The islands, only ten of which are inhabited, are spread throughout an area of approximately 77,000 square kilometers. The islands are low-lying coral-based formations capable of limited cultivation.
<>Coasts and Borders
India has 7,000 kilometers of seacoast and shares 14,000 kilometers of land frontier with six nations: Pakistan, China, Nepal, Bhutan, Bangladesh, and Burma. India claims a twelve-nautical-mile territorial sea and an exclusive economic zone of 200 nautical miles. The territorial seas total 314,400 square kilometers.
In the mid-1990s, India had boundary disagreements with Pakistan, China, and Bangladesh; border distances are therefore approximations. The partition of India in 1947 established two India-Pakistan frontiers: one on the west and one on the east (East Pakistan became Bangladesh in 1971).
Disputes over the state of Jammu and Kashmir led to hostilities between India and Pakistan in 1947. The January 1, 1949, cease-fire arranged by the United Nations (UN) divided control of Kashmir. India controls Jammu, the Vale of Kashmir, and the capital, Srinagar, while Pakistan controls the mountainous area to the northwest. Neither side accepts a divided Kashmir as a permanent solution. India regards as illegal the 1963 China-Pakistan border agreement, which ceded to China a portion of Pakistani-controlled Kashmir. The two sides also dispute the Siachen Glacier near the Karakoram Pass. Further India-Pakistan hostilities in the 1965 war were settled through the Soviet-brokered Tashkent Declaration.
In 1968 an international tribunal settled the dispute over the Rann of Kutch, a region of salt flats that is submerged for six months of the year in the state of Gujarat. The following year, a new border was demarcated that recognized Pakistan's claim to about 10 percent of the area.
In 1992 India completed fencing most of the 547-kilometer-long section of the boundary between the Indian state of Punjab and the Pakistani province of Punjab. This measure was undertaken because of the continuing unrest in the region caused by both ethnic and religious disputes among the local Indian population and infiltrators from both sides of the frontier. The more rugged terrain north of Punjab along the entire cease-fire line between India and Pakistan in Jammu and Kashmir continues to be subject to infiltration and local strife (see Political Issues, ch. 8; South Asia, ch. 9; Insurgent Movements and External Subversion, ch. 10).
The 2,000-kilometer-long border with China has eastern, central, and western sections. In the western section, the border regions of Jammu and Kashmir have been the scene of conflicting claims since the nineteenth century. China has not accepted India's definitions of the boundary and has carried out defense and economic activities in parts of eastern Kashmir since the 1950s. In the 1960s, China finished construction of a motor road across Aksai Chin (a region under dispute between India and China), the main transportation route linking China's Xinjiang-Uygur Autonomous Region and Tibet.
In the eastern section, the China-India boundary follows the McMahon Line laid down in 1914 by Sir Arthur Henry McMahon, the British plenipotentiary to a conference of Indian, British, and Chinese representatives at Simla (now known as Shimla, Himachal Pradesh). The Simla Convention, as the agreement is known, set the boundary between India and Tibet. Although the British and Tibetan representatives signed the agreement on July 3, 1914, the Chinese delegate declined to sign. The line agreed to by Britain and Tibet generally follows the crest of the eastern Himalayas from Bhutan to Burma. It serves as a legal boundary, although the Chinese have never formally accepted it. China continued to claim roughly the entire area of Arunachal Pradesh south of the McMahon Line in the early 1990s. In 1962 China and India fought a brief border war in this region, and China occupied certain areas south of the line for several months (see Nehru's Legacy, ch 1; The Experience of Wars, ch. 10). India and China took a major step toward resolving their border disputes in 1981 by opening negotiations on the issue. Agreements and talks held in 1993 and 1995 eased tensions along the India-China border (see China, ch. 9). Sikkim, which became an Indian state in 1975, forms the small central section of India's northern border and lies between Nepal and Bhutan.
India's border with Bangladesh is essentially the same as it was before East Pakistan became Bangladesh in 1971. Some minor disputes continued to occur over the size and number of the numerous enclaves each country had on either side of the border. These enclaves were established during the period from 1661 to 1712 during fighting between the Mughal Empire and the principality of Cooch Behar. This complex pattern of enclaves was preserved by the British administration and passed on intact to India and Pakistan.
The 1,300-kilometer frontier with Burma has been delimited but not completely demarcated. On March 10, 1967, the Indian and Burmese governments signed a bilateral treaty delimiting the boundary in detail. India also has a maritime boundary with Burma in the area of the northern Andaman Islands and Burma's Coco Islands in the Bay of Bengal. India's borders with Nepal and Bhutan have remained unchanged since the days of British rule. In 1977 India signed an accord with Indonesia demarcating the entire maritime boundary between the two countries. One year earlier, a similar accord was signed with the Maldives.
The country's rivers are classified as Himalayan, peninsular, coastal, and inland-drainage basin rivers. Himalayan rivers are snow fed and maintain a high to medium rate of flow throughout the year. The heavy annual average rainfall levels in the Himalayan catchment areas further add to their rates of flow. During the monsoon months of June to September, the catchment areas are prone to flooding. The volume of the rain-fed peninsular rivers also increases. Coastal streams, especially in the west, are short and episodic. Rivers of the inland system, centered in western Rajasthan state, are few and frequently disappear in years of scant rainfall. The majority of the South Asia's major rivers flow through broad, shallow valleys and drain into the Bay of Bengal.
The Ganga River basin, India's largest, includes approximately 25 percent of the nation's area; it is bounded by the Himalayas in the north and the Vindhya Range to the south. The Ganga has its source in the glaciers of the Greater Himalayas, which form the frontier between India and Tibet in northwestern Uttar Pradesh. Many Indians believe that the legendary source of the Ganga, and several other important Asian rivers, lies in the sacred Mapam Yumco Lake (known to the Indians as Manasarowar Lake) of western Tibet located approximately 75 kilometers northeast of the India-China-Nepal tripoint. In the northern part of the Ganga River basin, practically all of the tributaries of the Ganga are perennial streams. However, in the southern part, located in the states of Rajasthan and Madhya Pradesh, many of the tributaries are not perennial.
The Brahmaputra has the greatest volume of water of all the rivers in India because of heavy annual rainfall levels in its catchment basin. At Dibrugarh the annual rainfall averages 2,800 millimeters, and at Shillong it averages 2,430 millimeters. Rising in Tibet, the Brahmaputra flows south into Arunachal Pradesh after breaking through the Great Himalayan Range and dropping rapidly in elevation. It continues to fall through gorges impassable by man in Arunachal Pradesh until finally entering the Assam Valley where it meanders westward on its way to joining the Ganga in Bangladesh.
The Mahanadi, rising in the state of Madhya Pradesh, is an important river in the state of Orissa. In the upper drainage basin of the Mahanadi, which is centered on the Chhattisgarh Plain, periodic droughts contrast with the situation in the delta region where floods may damage the crops in what is known as the rice bowl of Orissa. Hirakud Dam, constructed in the middle reaches of the Mahanadi, has helped in alleviating these adverse effects by creating a reservoir.
The source of the Godavari is northeast of Bombay (Mumbai in the local Marathi language) in the state of Maharashtra, and the river follows a southeasterly course for 1,400 kilometers to its mouth on the Andhra Pradesh coast. The Godavari River basin area is second in size only to the Ganga; its delta on the east coast is also one of the country's main rice-growing areas. It is known as the "Ganga of the South," but its discharge, despite the large catchment area, is moderate because of the medium levels of annual rainfall, for example, about 700 millimeters at Nasik and 1,000 millimeters at Nizamabad.
The Krishna rises in the Western Ghats and flows east into the Bay of Bengal. It has a poor flow because of low levels of rainfall in its catchment area--660 millimeters annually at Pune. Despite its low discharge, the Krishna is the third longest river in India.
The source of the Kaveri is in the state of Karnataka, and the river flows southeastward. The waters of the river have been a source of irrigation since antiquity; in the early 1990s, an estimated 95 percent of the Kaveri was diverted for agricultural use before emptying into the Bay of Bengal. The delta of the Kaveri is so mature that the main river has almost lost its link with the sea, as the Kollidam, the distributary of the Kaveri, bears most of the flow.
The Narmada and the Tapti are the only major rivers that flow into the Arabian Sea. The Narmada rises in Madhya Pradesh and crosses the state, passing swiftly through a narrow valley between the Vindhya Range and spurs of the Satpura Range. It flows into the Gulf of Khambhat (or Cambay). The shorter Tapti follows a generally parallel course, between eighty kilometers and 160 kilometers to the south of the Narmada, flowing through the states of Maharashtra and Gujarat on its way into the Gulf of Khambhat.
Harnessing the waters of the major rivers that flow from the Himalayas is an issue of great concern in Nepal, India, and Bangladesh. Issues of flood control, drought prevention, hydroelectric power generation, job creation, and environmental quality--but also traditional lifestyles and cultural continuities--are at stake as these countries grapple with the political realities, both domestic and international, of altering the flow of the Ganga and Brahmaputra. Although India, Nepal, and Bangladesh seek to alleviate problems through cooperation over Himalayan rivers, irrigation projects altering the flow of Punjab-area rivers are likely to continue to be an irritant between India and Pakistan--countries between which cooperation is less likely to occur--in the second half of the 1990s. Internally, large dam projects, such as one on the Narmada River, are also controversial (see Development Programs, ch. 7).
The Himalayas isolate South Asia from the rest of Asia. South of these mountains, the climate, like the terrain, is highly diverse, but some geographers give it an overall, one-word characterization--violent. What geographers have in mind is the abruptness of change and the intensity of effect when change occurs--the onset of the monsoon rains, sudden flooding, rapid erosion, extremes of temperature, tropical storms, and unpredictable fluctuations in rainfall. Broadly speaking, agriculture in India is constantly challenged by weather uncertainty.
It is possible to identify seasons, although these do not occur uniformly throughout South Asia. The Indian Meteorological Service divides the year into four seasons: the relatively dry, cool winter from December through February; the dry, hot summer from March through May; the southwest monsoon from June through September when the predominating southwest maritime winds bring rains to most of the country; and the northeast, or retreating, monsoon of October and November.
The southwest monsoon blows in from sea to land. The southwest monsoon usually breaks on the west coast early in June and reaches most of South Asia by the first week in July (see fig. 6). Because of the critical importance of monsoon rainfall to agricultural production, predictions of the monsoon's arrival date are eagerly watched by government planners and agronomists who need to determine the optimal dates for plantings.
Theories about why monsoons occur vary. Conventionally, scientists have attributed monsoons to thermal changes in the Asian landmass. Contemporary theory cites other factors--the barrier of the Himalayas and the sun's northward tilt (which shifts the jet stream north). The hot air that rises over South Asia during April and May creates low-pressure areas into which the cooler, moisture-bearing winds from the Indian Ocean flow.These circumstances set off a rush of moisture-rich air from the southern seas over South Asia.
The southwest monsoon occurs in two branches. After breaking on the southern part of the Peninsula in early June, the branch known as the Arabian Sea monsoon reaches Bombay around June 10, and it has settled over most of South Asia by late June, bringing cooler but more humid weather. The other branch, known as the Bay of Bengal monsoon, moves northward in the Bay of Bengal and spreads over most of Assam by the first week of June. On encountering the barrier of the Great Himalayan Range, it is deflected westward along the Indo-Gangetic Plain toward New Delhi. Thereafter the two branches merge as a single current bringing rains to the remaining parts of North India in July.
The withdrawal of the monsoon is a far more gradual process than its onset. It usually withdraws from northwest India by the beginning of October and from the remaining parts of the country by the end of November. During this period, the northeast winds contribute to the formation of the northeast monsoon over the southern half of the Peninsula in October. It is also known as the retreating monsoon because it follows in the wake of the southwest monsoon. The states of Tamil Nadu, Karnataka, and Kerala receive most of their rainfall from the northeast monsoon during November and December. However, 80 percent of the country receives most of its rainfall from the southwest monsoon from June to September.
South Asia is subject to a wide range of climates--from the subfreezing Himalayan winters to the tropical climate of the Coromandel Coast and from the damp, rainy climate in the states of Assam and West Bengal to the arid Great Indian Desert. Based on precipitation and temperature, experts define seven climatic regions: the Himalayas, Assam and West Bengal, the Indo-Gangetic Plain, the Western Ghats and coast, the Deccan (the interior of the Peninsula south of the Narmada River), and the Eastern Ghats and coast (see fig. 7).
In the Himalayan region, climate varies with altitude. At about 2,000 meters, the average summer temperature is near 18°C; at 4,500 meters, it is rarely above 0°C. In the valleys, summer temperatures reach between 32°C and 38°C. The eastern Himalayas receive as much as 1,000 to 2,000 millimeters more precipitation than do the Western Himalayas, and floods are common.
Assam and West Bengal are extremely wet and humid. The southeastern part of the state of Meghalaya has the world's highest average annual rainfall, some 10,900 millimeters.
The Indo-Gangetic Plain has a varied climatic pattern. Rainfall and temperature ranges vary significantly between the eastern and western extremes (see table 2, Appendix). In the Peninsula region, the Western Ghats and the adjoining coast receive heavy rains during the southwest monsoon. Rainfall in the peninsular interior averages about 650 millimeters a year, although there is considerable variation in different localities and from year to year. The Eastern Ghats receive less rainfall than the western coast. Rainfall there ranges between 900 and 1,300 millimeters annually.
The northern Deccan region, bounded by the Western Ghats, the Vindhya Range and the Narmada River to the north, and the Eastern Ghats, receives most of its annual rainfall during the summer monsoon season. The southern Deccan area is in a "rain shadow" and receives only fifty to 1,000 millimeters of rainfall a year. Temperature ranges are wide--from some 15°C to 38°C--making this one of India's most comfortable climatic areas.
Throughout most of non-Himalayan India, the heat can be oppressive and sometimes, such as was experienced in 1994 and 1995, literally can be a killer. Hot, relatively dry weather is the norm before the southwest monsoons, which, along with heavy rains and high humidity, bring cloud cover that lowers temperatures slightly. Temperatures reach the upper 30s°C and can reach as high as 48°C during the day in the premonsoon months.
India has experienced some of the world's most devastating earthquakes. Some 19,000 people died in Kangra District, northeastern Himachal Pradesh, in April 1905, and more than 30,000 died in Maharashtra and Andhra Pradesh in September 1993. Although resulting in less extensive loss of life, major earthquakes occurred in Assam in 1950 (more than 1,500 killed) and in Uttarkashi District, Uttar Pradesh, in 1991 (1,600 killed).