Himalayas - geography. I INTRODUCTION Himalayas, also Himalaya (Sanskrit for "abode of snow"), mountain system in Asia, forming a broad continuous arc for nearly 2,600 km (1,600 mi) along the northern fringes of the Indian subcontinent, from the bend of the Indus River in the northwest to the Brahmaputra River in the east. The Himalayas range, averaging 320 to 400 km (200 to 250 mi) in width, rises sharply from the Gangetic Plain. North of this mountain belt lies the Tibetan Plateau (Qing Zang Gaoyuan). The Himalayas form the earth's highest mountain region, containing 9 of the 10 highest peaks in the world. Among these peaks are the world's highest mountain, Mount Everest (8,850 m/29,035 ft), which is on the Nepal-Tibet border; the second highest peak, K2 or Mount Godwin Austen (8,611 m/28,251 ft), located on the border between China and Jammu and Kashm?r, a territory claimed by India and Pakistan; the third highest peak, K?nchenjunga (8,598 m/28,209 ft) on the Nepal-India border; Mak?lu (8,481 m/27,824 ft) on the Nepal-Tibet border; Dhaul?giri (8,172 m/26,811 ft) and Annap? rna 1 (8,091 m/26,545 ft) in Nepal; Nanga Parbat (8,125 m/26,657 ft) in the Pakistani-controlled portion of Jammu and Kashm?r; and Nanda Devi (7817 m/25,645 ft) in India. II GEOLOGIC FORMATION AND STRUCTURE The Himalayan mountain system developed in a series of stages 30 to 50 million years ago. The Himalayan range was created from powerful earth movements that occurred as the Indian plate pressed against the Eurasian continental plate (see Plate Tectonics). The earth movements raised the deposits laid down in the ancient, shallow Tethys Sea (on the present site of the mountains) to form the Himalayan ranges from Pakistan eastward across northern India, and from Nepal and Bhutan to the Myanmar (Burmese) border. Even today the mountains continue to develop and change, and earthquakes and tremors are frequent in the area. III TOPOGRAPHY Physically, the Himalayas forms three parallel zones: the Great Himalayas, the Middle Himalayas (also known as the Inner or Lesser Himalayas), and the Sub-Himalayas, which includes the Siw?lik Range and foothills and the Tar? i and Duars piedmont (an area of land formed or lying at the foot of a mountain or mountain range). Each of these lateral divisions exhibit certain similar topographic features. The Great Himalayas, the highest zone, consists of a huge line of snowy peaks with an average height exceeding 6,100 m (20,000 ft). The width of this zone, composed largely but not entirely of gneiss and granite, is about 24 km (about 15 mi). Spurs from the Great Himalayas project southwards into the Middle Himalayas in an irregular fashion. The Nepal and Sikkim (a state of northern India) portion of the Great Himalayas contains the greatest number of high peaks. The snow line on the southern slopes of the Great Himalayas varies from 4,480 m (14,700 ft) in the eastern and central Himalayas of Nepal and Sikkim to 5,180 m (17,000 ft) in the western Himalayas. To the north of the Great Himalayas are several ranges such as the Z?sk ?r, Ladakh, and the Kailas. The Karakoram Range lies on the Tibetan side of the Great Himalayas. The Great Himalayan region is one of the few remaining isolated and inaccessible areas in the world today. Some high valleys in the Great Himalayas are occupied by small clustered settlements. Extremely cold winters and a short growing season limit the farmers to one crop per year, most commonly potatoes or barley. The formidable mountains have limited the development of large-scale trade and commerce despite the construction of highways across the mountains linking Nepal and Pakistan to China. Older trails, which cross the mountains at high passes, also have limited trade and are open only during the summer months. The Middle Himalayas range, which has a width of about 80 km (about 50 mi), borders the Great Himalayan range on the south. It consists principally of high ranges both within and outside of the Great Himalayan range. Some of the ranges of the Middle Himalayas are the N? g Tibba, the Dhaola Dh?r, the P?r Panj? l, and the Mah?bh ?rat. The Middle Himalayas possess a remarkable uniformity of height; most are between 1,830 and 3,050 m (between 6000 and 10,000 ft). The Middle Himalayas region is a complex mosaic of forest-covered ranges and fertile valleys. While not as forbidding as the Great Himalayas to the north, this range has nonetheless served to isolate the valleys of the Himalayas from the plains of the Indus and Ganges rivers in Pakistan and northern India. Except for the major valley centers such as Sr?nagar, K?ngra, and Kathmandu, and hill towns such as Simla, Mussoorie, and D?rjiling (Darjeeling), the region is moderately populated. Within the Middle Himalayas the intervening mountain ranges tend to separate the densely populated valleys. The numerous gorges and rugged mountains make surface travel difficult in any direction. Few roads or transport routes exist between towns, partly because it is expensive to build them over the high, rough terrain. Only major population centers are linked by air and roads with principal cities in India and Pakistan. The Sub-Himalayas, which is the southernmost and the lowest zone, borders the plains of North India and Pakistan. It comprises the Siw?lik Range and foothills as well as the narrow piedmont plain at the base of the mountains. The width of the Sub-Himalayas gradually narrows from about 48 km (about 30 mi) in the west until it nearly disappears in Bhutan and eastern India. A characteristic feature of the Sub-Himalayas is the large number of long, flat-bottomed valleys known as duns, which are usually spindle-shaped and filled with gravelly alluvium. South of the foothills lies the Tar?i and Duars plains. The southern part of the Tar?i and Duars plains is heavily farmed. The northern part was forest inhabited by wild animals until about the 1950s. Most of the forests of this region have been destroyed, and much of the land has been reclaimed for agriculture. IV CLIMATE The Himalayas influences the climate of the Indian subcontinent by sheltering it from the cold air mass of Central Asia. The range also exerts a major influence on monsoon and rainfall patterns. Within the Himalayas climate varies depending on elevation and location. Climate ranges from subtropical in the southern foothills, with average summer temperatures of about 30° C (about 86° F) and average winter temperatures of about 18° C (about 64° F); warm temperate conditions in the Middle Himalayan valleys, with average summer temperatures of about 25° C (about 77° F) and cooler winters; cool temperate conditions in the higher parts of the Middle Himalayas, where average summer temperatures are 15 to 18° C (59 to 64° F) and winters are below freezing; to a cold alpine climate at higher elevations, where summers are cool and winters are severe. At elevations above 4,880 m (16,000 ft) the climate is very cold with below freezing temperatures and the area is permanently covered with snow and ice. The eastern part of the Himalayas receives heavy rainfall; the western part is drier. V PLANT AND ANIMAL LIFE The natural vegetation is influenced by climate and elevation. Tropical, moist deciduous forest at one time covered all of the Sub-Himalayan area. With few exceptions most of this forest has been cut for commercial lumber or agricultural land. In the Middle Himalayas at elevations between 1,520 and 3,660 m (between 5,000 and 12,000 ft) natural vegetation consists of many species of pine, oak, rhododendron, poplar, walnut, and larch. Most of this area has been deforested; forest cover remains only in inaccessible areas and on steep slopes. Below the timber line the Great Himalayas contains valuable forests of spruce, fir, cypress, juniper, and birch. Alpine vegetation occupies higher parts of the Great Himalayas just below the snow line and includes shrubs, rhododendrons, mosses, lichens, and wildflowers such as blue poppies and edelweiss. These areas are used for grazing in summer by the highland people of the Great Himalayas. Animals such as tigers, leopards, rhinoceroses, and many varieties of deer once inhabited the forested areas of the Sub-Himalayan foothills and the Tar?i plain. As a result of deforestation the habitat of most of the wildlife has been destroyed. They are now restricted to special protected areas such as the Jaldapara and Kaziranga sanctuaries in India (see Kaziranga National Park) and the Chitawan preserve in Nepal. There are few animals in the Middle Himalayas because of extensive deforestation. In the Great Himalayas musk deer, wild goats, sheep, wolves, and snow leopards are found. The existence of the Abominable Snowman or Yeti has been reported by highland Sherpas in Nepal but has eluded discovery by several expeditions. VI PEOPLE AND ECONOMY The population, settlement, and economic patterns within the Himalayas have been greatly influenced by the variations in topography and climate, which impose harsh living conditions and tend to restrict movement and communication. People living in remote, isolated valleys have generally preserved their cultural identities. However, improvements in transportation and communication, particularly satellite television programs from Europe and the United States, are bringing access from the outside world to remote valleys. These outside influences are affecting traditional social and cultural structure. Nearly 40 million people inhabit the Himalayas. Generally, Hindus of Indian heritage are dominant in the Sub-Himalayas and the Middle Himalayan valleys from eastern Kashm?r to Nepal. To the north Tibetan Buddhists inhabit the Great Himalayas from Ladakh to northeast India. In central Nepal, in an area between about 1,830 and 2,440 m (between about 6,000 and 8,000 ft), the Indian and Tibetan cultures have intermingled, producing a combination of Indian and Tibetan traits. The eastern Himalayas in India and nearby areas of eastern Bhutan are inhabited by animistic people whose culture is similar to those living in northern Myanmar and Yunnan province in China. People of western Kashm?r are Muslims and have a culture similar to the inhabitants of Afghanistan and Iran. The economy of the Himalayas as a whole is poor with low per capita income. Much of the Himalayas area is characterized by a very low economic growth rate combined with a high rate of population growth, which contributes to stagnation in the already low level of per capita gross national product. Most of the population is dependent on agriculture, primarily subsistence agriculture; modern industries are lacking. Mineral resources are limited. The Himalayas has major hydroelectric potential, but the development of hydroelectric resources requires outside capital investment. The skilled labor needed to organize and manage development of natural resources is also limited due to low literacy rates. Most of the Himalayan communities face malnutrition, a shortage of safe drinking water, and poor health services and education systems. Agricultural land is concentrated in the Tar?i plain and in the valleys of the Middle Himalayas. Patches of agricultural land have also been carved out in the mountainous forested areas. Rice is the principal crop in eastern Tar?i and the well-watered valleys. Corn is also an important rain-fed crop on the hillsides. Other cereal crops are wheat, millet, barley, and buckwheat. Sugarcane, tea, oilseeds, and potatoes are other major crops. Food production in the Himalayas has not kept up with the population growth. The major industries include processing food grains, making vegetable oil, refining sugar, and brewing beer. Fruit processing is also important. A wide variety of fruits are grown in each of the major zones of the Himalayas, and making fruit juices is a major industry in Nepal, Bhutan, and in the Indian Himalayas. Since 1950 tourism has emerged as a major growth industry in the Himalayas. Nearly 1 million visitors come to the Himalayas each year for mountain trekking, wildlife viewing, and pilgrimages to major Hindu and Buddhist sacred places. The number of foreign visitors has increased in recent years, as organized treks to the icy summits of the Great Himalayas have become popular. While tourism is important to the local economy, it has had an adverse impact on regions where tourist numbers exceed the capacity of recreational areas. Historically, all transport in the Himalayas has been by porters and pack animals. Porters and pack animals are still important, but the construction of major roads and the development of air routes have changed the traditional transportation pattern. Major urban centers such as Kathmandu, Simla, and Sr?nagar, as well as important tourist destinations, are served by airlines. Railways link Simla and D?rjiling, but in most of the Himalayas there are no railroads. The bulk of goods from the Himalayas, as well as goods destined for places within the Himalayas, generally come to Indian railheads, located in the Tar?i, by road. The pack animals and porters transport goods from road heads to the interior and back. VII ENVIRONMENTAL ISSUES Economic changes and population increases are threatening the ecology of the Himalayas. In recent years deforestation in the foothills and the Middle Himalayas and overgrazing on the high pastures have led to soil erosion and other environmental problems. Deforestation is a particular concern in the western Himalayas, where increased demand for firewood, extensive tree trimming in order to feed livestock, and construction of roads in the border regions have increased the destruction rate of forests and the number of landslides. Rapid population growth has accelerated pollution, and Himalayan streams that were once clear are now polluted with refuse and sewage. Hill people who use the water for drinking suffer from dysentery; cholera and typhoid epidemics are also common. Large lakes like Dal in Kashm?r and Naini Lake (Nainital) have also become polluted. Regional variations in environmental degradation exist in the Himalayas. Conditions range from a critical situation in the Himalayas of Nepal, Sikkim, Uttarakhand, and Kashm?r to a moderately serious situation in Bhutan and the eastern Himalayas. If rapid development continues in Bhutan and the eastern Himalayas without due regard for conservation, the problems there may assume critical proportions in the near future. The governments of India, Nepal, and Bhutan are aware of the dangers of environmental degradation in the Himalayas, and environmental management concerns are being integrated in development projects in this region. Contributed By: Pradyumna P. Karan Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.