Geography of Nepal

Nepal measures about 800 kilometers (497 mi) along its Himalayan axis by 150 to 250 kilometers (93 to 155 mi) across. With 147,181 square kilometers (56,827 sq mi) it slightly outranks the state of Arkansas in the United States. Nepal is landlocked by India on three sides and China's Tibet Autonomous Region to the north. West Bengal's narrow Siliguri Corridor or Chicken's Neck separate Nepal and Bangladesh. To the east are India and Bhutan. Nepal depends on India for goods transport facilities and access to the sea, even for most goods imported from China.

The land

For a small country, Nepal has tremendous geographic diversity. It rises from as low as 59 metres (194 ft) elevation in the tropical Teraiâ€"the northern rim of the Gangetic Plain, beyond the perpetual snow line to some 90 peaks over 7,000 metres (22,966 ft) including Earth's highest 8,848 metres (29,029 ft) Mount Everest or Sagarmatha. In addition to the continuum from tropical warmth to cold comparable to polar regions, average annual precipitation varies from as little as 160 millimetres (6.3 in) in the rainshadow north of the Himalaya to as much as 5,500 millimetres (216.5 in) on windward slopes.

Along a south-to-north transect, Nepal can be divided into three belts: Terai, Hill and Mountain Regions. In the other direction it is divided into three major river systems, from east to west: Koshi, Gandaki/Narayani and Karnali (including the Mahakali/Sarda along the western border), all tributaries of the Ganges. The Ganges-Yarlung Zangbo/Brahmaputra watershed largely coincides with the Nepal-Tibet border, however several Ganges tributaries rise inside Tibet.

Terai Region

The Terai (also Tarai) or Madhesh region begins at the Indian border and includes the southernmost part of the flat, intensively farmed Gangetic Plain called the Outer Terai. By the 19th century, timber and other resources were being exported to India. Industrialization based on agricultural products such as jute began in the 1930s and infrastructure such roadways, railways and electricity were extended across the border before it reached Nepal's hill regions.

The Outer Terai is culturally more similar to adjacent parts of India's Bihar and Uttar Pradesh than to the hill region of Nepal, although government offices are largely staffed by Paharis. Nepali is taught in schools and often spoken in government offices, however the local population mostly uses the languages spoken across the border in Bihar and U.P.

The Outer Terai ends at the base of the first range of foothills called the Siwaliks or Churia. This range has a densely forested skirt of coarse alluvium called the bhabhar. Below the bhabhar, finer, less permeable sediments force groundwater to the surface in a zone of springs and marshes. In Persian, terai refers to wet or marshy ground. Before the use of DDT this was dangerously malarial. Nepal's rulers used this for a defensive frontier called the char kose jhadi (four kos forest, one kos equalling about three kilometers or two miles).

Above the bhabhar belt, the Siwaliks rise to about 700 metres (2,297 ft) with peaks as high as 1,000 metres (3,281 ft), steeper on their southern flanks because of faults known as the Main Frontal Thrust. This range is composed of poorly consolidated, coarse sediments that do not retain water or support soil development so there is virtually no agricultural potential and sparse population.

In several places beyond the Siwaliks there are dūn valleys called Inner Terai (भित्री मधेश; Bhitrī Madhesh). These valleys have productive soil but were dangerously malarial except to indigenous Tharu people who had genetic resistance. In the mid-1950s DDT came into use to suppress mosquitos and the way was open to settlement from the land-poor hills, to the detriment of the Tharu.

The Terai ends and the Hills begin at a higher range of foothills called the Mahabharat Range.

Hill Region

Situated south of the Mountain Region, the Hill Region (Pahar in Nepali) is mostly between 700 and 3,000 metres (2,000 and 10,000 ft) altitude. This region begins at the Mahabharat Range (Lesser Himalaya) where a fault system called the Main Boundary Thrust creates an escarpment 1,000 to 1,500 metres (3,000 to 5,000 ft) high, to a crest between 1,500 and 2,700 metres (5,000 and 9,000 ft).

These steep southern slopes are nearly uninhabited, thus an effective buffer between languages and culture in the Terai and Hill regions. Hindu Paharis mainly populate river and stream bottoms that enable rice cultivation and are warm enough for winter/spring crops of wheat and potato. The increasingly urbanized Kathmandu and Pokhara valleys fall within the Hill region. Newars are an indigenous ethnic group with their own Tibeto-Burman language. The Newar were originally indigenous to the Kathmandu valley but have spread into Pokhara and other towns alongside urbanized Pahari.

Other indigenous janajati ethnic groups -â€" natively speaking highly localized Tibeto-Burman languages and dialects -â€" populate hillsides up to about 2,500 metres (8,000 ft). This group includes Magar and Kham Magar west of Pokhara, Gurung south of the Annapurnas, Tamang around the periphery of Kathmandu Valley and Rai, Koinch Sunuwar and Limbu further east. Temperate and subtropical fruits are grown as cash crops. Marijuana was grown and processed into Charas (hashish) until international pressure persuaded the government to outlaw it in 1976. There is increasing reliance on animal husbandry with elevation, using land above 2,000 metres (7,000 ft) for summer grazing and moving herds to lower elevations in winter. Grain production has not kept pace with population growth at elevations above 1,000 metres (3,300 ft) where colder temperatures inhibit double cropping. Food deficits drive emigration out of the hills in search of employment.

The Hill region ends where ridges begin substantially rising out of the Temperate climate zone into subalpine climate above 3,000 metres (10,000 ft).

Mountain Region

The Mountain Region or Parbat begins where high ridges (Nepali: लेक; lekh) begin substantially rising above 3,000 metres (10,000 ft) into the subalpine and alpine zone which are mainly used for seasonal pasturage. A few tens kilometers further north the high Himalaya abruptly rise along the Main Central Thrust fault zone above the snow line at 5,000 to 5,500 metres (16,400 to 18,000 ft). Some 90 of Nepal's peaks exceed 7,000 metres (23,000 ft) and eight exceed 8,000 metres (26,247 ft) including Mount Everest at 8,848 metres (29,029 ft) and Kanchenjunga at 8,598 metres (28,209 ft).

Unlike the Mahabharats, the Himalaya are not continuous across Nepal. Instead there are some 20 subranges including the Kanchenjunga massif along the Sikkim border, Mahalangur Himal around Mt. Everest. Langtang north of Kathmandu, Annapurna and Manaslu north of Pokhara, then Dhaulagiri further west with Kanjiroba north of Jumla and finally Gurans Himal in the far west.

Trans-Himalayan Region

The main watershed between the Brahmaputra (called Yarlung Tsangpo in Tibet) and the Ganges system (including all of Nepal) actually lies north of the highest ranges. Alpine, often semi-arid valleysâ€"including Humla, Jumla, Dolpo, Mustang, Manang and Khumbuâ€"cut between Himalayan subranges or lie north of them. Some of these valleys historically were more accessible from Tibet than Nepal and are populated by people with Tibetan affinities called Bhotiya or Bhutia including the famous Sherpas in Kumbu valley near Mount Everest. With Chinese cultural hegemony in Tibet itself, these valleys have become repositories of traditional ways. Valleys with better access from the hill regions to the south are culturally linked to Nepal as well as Tibet, notably the Kali Gandaki Gorge where Thakali culture shows influences in both directions.

Permanent villages in the mountain region stand as high as 4,500 metres (15,000 ft) with summer encampments even higher. Bhotiyas graze yaks, grow cold-tolerant crops such as potatoes, barley, buckwheat and millet. They traditionally traded across the mountains, e.g., Tibetan salt for rice from lowlands in Nepal and India. Since trade was restricted in the 1950s they have found work as high altitude porters, guides, cooks and other accessories to tourism and alpinism.

Climate

Altitudinal Belts

Nepal's latitude is about the same as that of Florida, however with elevations ranging from less than 100 meters (300 ft) to over 8,000 meters (26,000 ft) and precipitation from 160 millimeters (6 in) to over 5,000 millimeters (16 ft) the country has eight climate zones from tropical to perpetual snow.

The tropical zone below 1,000 meters (3,300 ft) experiences frost less than once per decade. It can be subdivided into lower tropical (below 300 meters or 1,000 ft.) with 18% of the nation's land area) and upper (18% of land area) tropical zones. The best mangoes and well as papaya and banana are largely confined to the lower zone. Other fruit such as litchee, jackfruit, citrus and mangoes of lower quality grow in the upper tropical zone as well. Winter crops include grains and vegetables typically grown in temperate climates. The Outer Terai is virtually all in the lower tropical zone. Inner Terai valleys span both tropical zones. The Sivalik Hills are mostly upper tropical. Tropical climate zones extend far up river valleys across the Middle Hills and even into the Mountain regions.

The subtropical climate zone from 1,000 to 2,000 meters (3,300 to 6,600 ft) occupies 22% of Nepal's land area and is the most prevalent climate of the Middle Hills above river valleys. It experiences frost up to 53 days per year, however this varies greatly with elevation, proximity to high mountains and terrain either draining or ponding cold air drainage. Crops include rice, maize, millet, wheat, potato, stone fruits and citrus.

The great majority of Nepal's population occupies the tropical and subtropical climate zones. In the Middle Hills, upper-caste Hindus are concentrated in tropical valleys which are well suited for rice cultivation while Janajati ethnic groups mostly live above in the subtropical zone and grow other grains more than rice.

The Temperate climate zone from 2,000 to 3,000 meters (6,600 to 9,800 ft) occupies 12% of Nepal's land area and has up to 153 annual days of frost. It is encountered in higher parts of the Middle Hills and throughout much of the Mountain region. Crops include cold-tolerant rice, maize, wheat, barley, potato, apple, walnut, peach, various cole, amaranthus and buckwheat.

The Subalpine zone from 3,000 to 4,000 meters (9,800 to 13,100 ft) occupies 9% of Nepal's land area, mainly in the Mountain and Himalayan regions. It has permanent settlements in the Himalaya, but further south it is only seasonally occupied as pasture for sheep, goats, yak and hybrids in warmer months. There are up to 229 annual days of frost here. Crops include barley, potato, cabbage, cauliflower, amaranthus, buckwheat and apple. Medicinal plants are gathered.

The Alpine zone from 4,000 to 5,000 meters (13,100 to 16,400 ft) occupies 8% of the country's land area. There are a few permanent settlements above 4,000 meters. There is virtually no plant cultivation although medicinal herbs are gathered. Sheep, goats, yaks and hybrids are pastured in warmer months.

Above 5,000 meters the climate becomes Nival and there is no human habitation or even seasonal use.

Arid and semi-arid land in the rainshadow of high ranges have a Transhimalayan climate. Population density is very low. Cultivation and husbandry conform to subalpine and alpine patterns but depend on snowmelt and streams for irrigation.

Precipitation generally decreases from east to west with increasing distance from the Bay of Bengal, source of the summer monsoon. Eastern Nepal gets about 2,500 mm (100 in) annually; the Kathmandu area about 1,400 mm (55 in) and western Nepal about 1,000 mm (40 in). This pattern is modified by adabiatic effects as rising air masses cool and drop their moisture content on windward slopes, then warm up as they descend so relative humidity drops. Annual precipitation reaches 5,500 mm (18 ft) on windward slopes in the Annapurna Himalaya beyond a relatively low stretch of the Mahabharat Range. In rainshadows beyond the high mountains, annual precipitation drops as low as 160 mm (6 in).

Seasons

The year is divided into a wet season from June to Septemberâ€"as summer warmth over Inner Asia creates a low pressure zone that draws in moist air from the Indian Oceanâ€"and a dry season from October to June as cold temperatures in the vast interior creates a high pressure zone causing dry air to flow outward. April and May are months of intense water stress when cumulative effects of the long dry season are exacerbated by temperatures rising over 40 °C (104 °F) in the tropical climate belt. Seasonal drought further intensifies in the Siwaliks hills consisting of poorly consolidated, coarse, permeable sediments that do not retain water, so hillsides are often covered with drought-tolerant scrub forest. In fact much of Nepal's native vegetation adapted to withstand drought, but less so at higher elevations where cooler temperatures mean less water stress.

The summer monsoon may be preceded by a buildup of thunderstorm activity that provides water for rice seedbeds. Sustained rain on average arrives in mid-June as rising temperatures over Inner Asia creates a low pressure zone that draws in moist air from the Indian Ocean, but this can vary up to a month. Significant failure of monsoon rains historically meant drought and famine while above-normal rains still cause flooding and landslides with losses in human lives, farmland and buildings. The monsoon also complicates transportation with roads and trails washing out while unpaved roads and airstrips may become unusable and cloud cover reduces safety margins for aviation. Rains diminish in September and generally end by mid-October, ushering in generally cool, clear, and dry weather, as well as the most relaxed and jovial period in Nepal. By this time, the harvest is completed and people are in a festive mood. The two biggest and most important Hindu festivalsâ€"Dashain and Tihar (Dipawali)â€"arrive during this period, about one month apart. The post monsoon season lasts until about December.

After the post monsoon comes the winter monsoon, a strong north easterly flow marked by occasional, short rainfalls in the lowlands and plains and snowfalls in the high-altitude areas. In this season the Himalayas function as a barrier to cold air masses from Inner Asia, so southern Nepal and northern India have warmer winters than would otherwise be the case. April and May are dry and hot, especially below 1,200 meters (4,000 ft) where afternoon temperatures may exceed 40 °C (104 °F).

Environment

The dramatic changes in elevation along this transect result in a variety of biomes, from tropical savannas along the Indian border, to subtropical broadleaf and coniferous forests in the hills, to temperate broadleaf and coniferous forests on the slopes of the Himalaya, to montane grasslands and shrublands, and finally rock and ice at the highest elevations.

This corresponds to the Terai-Duar savanna and grasslands ecoregion.

Subtropical forests dominate the lower elevations of the Hill Region. They form a mosaic running east-west across Nepal, with Himalayan subtropical broadleaf forests between 500 and 1,000 meters (1,600 and 3,300 ft) and Himalayan subtropical pine forests between 1,000 and 2,000 meters (3,300 and 6,600 ft). At higher elevations, to 3,000 meters (10,000 ft), are found temperate broadleaf forests: eastern Himalayan broadleaf forests to the east of the Gandaki River and western Himalayan broadleaf forests to the west.

The native forests of the Mountain Region change from east to west as precipitation decreases. They can be broadly classified by their relation to the Gandaki River. From 3,000 to 4,000 meters (10,000 to 13,000 ft) are the eastern and western Himalayan subalpine conifer forests. To 5,500 meters (18,000 ft) are the eastern and western Himalayan alpine shrub and meadows.

Environmental concerns

Natural hazards

Earthquakes, severe thunderstorms, flooding, landslides, drought, and famine depending on the timing, intensity, and duration of the summer monsoons

Environment - current issues

Deforestation (overuse of wood for fuel and lack of alternatives); contaminated water (with human and animal wastes, agricultural runoff, and industrial effluents); wildlife conservation; vehicular emissions

Environment - international agreements

• Party to: Biodiversity, Climate Change, Climate Change-Kyoto Protocol, Desertification, Endangered Species, Hazardous Wastes, Law of the Sea, Ozone Layer Protection, Tropical Timber 83, Tropical Timber 94, Wetlands
• Signed, but not ratified: Marine Life Conservation
• Existing and proposed dams, barrages and canals for flood control, irrigation and hydroelectric generation

Geography - note

Landlocked; strategic location between China and India; contains eight of world's 10 highest peaks, including Mount Everest and Kanachenjunga â€" the world's tallest and third tallest â€" on the borders with China and India respectively

River systems

Nepal has three categories of rivers. The largest systems -â€" from east to west Koshi, Gandaki/Narayani, Karnali/Goghra and Mahakaliâ€"originate in multiple tributaries rising in or beyond the high Himalaya that maintain substantial flows from snowmelt through the hot, droughty spring before the summer monsoon. These tributaries cross the highest mountains in deep gorges, flow south through the Middle Hills, then join in candelabra-like configuration before crossing the Mahabharat Range and emerging onto the plains where they have deposited megafans exceeding 10,000 km² (4,000 sq mi) area.

The Koshi is also called Sapta Koshi for its seven Himalayan tributaries in eastern Nepal: Indrawati, Sun Koshi, Tama Koshi, Dudh Koshi, Liku, Arun, and Tamur. The Arun rises in Tibet some 150 kilometers (100 mi) beyond Nepal's northern border. A tributary of the Sun Koshi, Bhote Koshi also rises in Tibet and is followed by the Arniko Highway connecting Kathmandu and Lhasa.

The Gandaki/Narayani has seven Himalayan tributaries in the center of the country: Daraudi, Seti Gandaki, Madi, Kali, Marsyandi, Budhi, and Trisuli also called Sapta Gandaki. The Kali Gandaki rises on the edge of the Tibetan Plateau and flows through the semi-independent Kingdom of Mustang, then between the 8,000 meter Dhaulagiri and Annapurna ranges in the world's deepest valley. The Trisuli rises north of the international border inside Tibet. After the seven upper tributaries join, the river becomes the Narayani inside Nepal and is joined by the (East) Rapti from Chitwan Valley. Crossing into India, its name changes to Gandak.

The Karnali drains western Nepal, with the Bheri and Seti as major tributaries. The upper Bheri drains Dolpo, a remote valley beyond the Dhaulagiri Himalaya with traditional Tibetan cultural affinities. The upper Karnali rises inside Tibet near sacred Lake Manasarovar and Mount Kailash. The area around these features is the hydrographic nexus of South Asia since it holds the sources of the Indus and its major tributary the Sutlej, the Karnaliâ€"a Ganges tributaryâ€"and the Yarlung Tsangpo/Brahmaputra. It is the center of the universe according to traditional cosmography. The Mahakali or Kali along the Nepal-India border on the west joins the Karnali in India, where the river is known as Goghra or Ghaghara.

Second category rivers rise in the Middle Hills and Mahabharat Range, from east to west the Mechi, Kankai and Kamala south of the Kosi; the Bagmati that drains Kathmandu Valley between the Kosi and Gandaki systems, then the West Rapti and the Babai between the Gandaki and Karnali systems. Without glacial sources, annual flow regimes in these rivers are more variable although limited flow persists through the dry season.

Third category rivers rise in the outermost Siwalik foothills and are mostly seasonal.

None of these river systems support significant commercial navigation. Instead, deep gorges create obstacles to establishing transport and communication networks and de-fragmenting the economy. Foot-trails are still primary transportation routes in many hill districts.

River management

Rivers in all three categories are capable of causing serious floods. Koshi River in the first category caused a major flood in August 2008 in Bihar state, India after breaking through a poorly maintained embankment just inside Nepal. The West Rapti in the second category is called Gorakhpur's Sorrow for its history of urban flooding. Third category Terai rivers are associated with flash floods. Since uplift and erosion are more or less in equilibrium in the Himalaya, at least where the climate is humid, rapid uplift must be balanced out by annual increments of millions tonnes of sediments washing down from the mountains; then on the plains settling out of suspension on vast alluvial fans over which rivers meander and change course at least every few decades, causing some experts to question whether manmade embankments can contain the problem of flooding. Traditional Mithila culture along the lower Koshi in Nepal and Bihar celebrated the river as the giver of life for its fertile alluvial soil, yet also the taker of life through its catastrophic floods.

Large reservoirs in the Middle Hills may be able to capture peak flows and mitigate downstream flooding, to store surplus monsoon flows for dry season irrigation and to generate electricity. Water for irrigation is especially compelling because the Indian Terai is suspected to have entered a food bubble where dry season crops are dependent on water from tubewells that in the aggregate are unsustainably "mining" groundwater. Depletion of acquifers without building upstream dams as a sustainable alternative water source could precipitate a Malthusian catastrophe in India's food insecure states Uttar Pradesh and Bihar , with over 300 million combined population. With India already experiencing a Naxaliteâ€"Maoist insurgency in Bihar, Jharkhand and Andra Pradesh, Nepalese reluctance to agree to water projects could even seem an existential threat to India.

As Nepal builds barrages to divert more water for irrigation during the dry season preceding the summer monsoon, there is less for downstream users in Bangladesh and India's Bihar and Uttar Pradesh states. The best solution could be building large upstream reservoirs, to capture and store surplus flows during summer monsoon as well as providing flood control benefits to Bangladesh and India. Then water sharing agreements could allocate a portion of the stored water to be left to flow into India during the following dry season.

Nevertheless, building dams in Nepal is controversial for several reasons. First, the region is seismically active. Dam failures caused by earthquakes could cause tremendous death and destruction downstream, particularly on the densely populated Gangetic Plain. Second, global warming has led to the formation of glacial lakes dammed by unstable moraines. Sudden failures of these moraines can cause floods with cascading failures of manmade structures downstream. Third, sedimentation rates in the Himalaya are extremely high, leading to rapid loss of storage capacity as sediments accumulate behind dams. Fourth, there are complicated questions of cross-border equity in how India and Nepal would share costs and benefits that have proven difficult to resolve in the context of frequent acrimony between the two countries.

Area

• Total: 147,181 km² (56,827 sq mi)
• Land: 143,181 km² (55,282 sq mi)
• Water: 4,000 km² (1,544 sq mi)

Coastline

0 km (landlocked)

Maritime claims

None (landlocked)

Elevation extremes

• Lowest point: Musaharniya, Dhanusa district 59 m
• Highest point: Sagarmatha (Mount Everest) 8,848 m

Resources and land use

Natural resources

Quartz, water, timber, hydropower, scenic beauty, small deposits of lignite, copper, cobalt, iron ore

Land use

• Arable land: 16.0%
• Permanent crops: 0.8%
• Other: 83.2% (2001)

Irrigated land

11,680 km² (2003) Nearly 50% of arable land

Total renewable water resources

210.2 km³ (2011)

Forests

25.4% of Nepal's land area, or about 36,360 km² (14,039 sq mi) is covered with forest according to FAO figures from 2005. FAO estimates that around 9.6% of Nepal's forest cover consists of primary forest which is relatively intact. About 12.1% Nepal's forest is classified as protected while about 21.4% is conserved according to FAO. About 5.1% Nepal's forests are classified as production forest. Between 2000 and 2005, Nepal lost about 2,640 km² (1,019 sq mi) of forest. Nepal's 2000â€"2005 total deforestation rate was about 1.4% per year meaning it lost an average of 530 km² (205 sq mi) of forest annually. Nepal's total deforestation rate from 1990 to 2000 was 920 km² (355 sq mi) or 2.1% per year. The 2000â€"2005 true deforestation rate in Nepal, defined as the loss of primary forest, is -0.4% or 70 km² (27 sq mi) per year.

Deforestation is driven by multiple processes. Virtually throughout the nation, over-harvest of firewood remains problematic. Despite the availability of liquefied petroleum gas in towns and cities, firewood is sold more at energy-competitive prices because cutting and selling it is a fallback when better employment opportunities aren't forthcoming. Firewood still supplies 80% of Nepal's energy for heating and cooking. Harvesting construction timber and lopping branches for fodder for cattle and other farm animals are also deforestation/degradation drivers in all geographic zones.

Illegal logging is a problems in the Siwaliks, with sawlogs smuggled into India. Clearing for resettlement and agriculture expansion also causes deforestation as does urban expansion, building infrastructure such as schools, hospitals, electric transmission lines, water tanks, police and army barracks, temples and picnic areas.

In the Middle Hills road construction, reservoirs, transmission lines and extractive manufacturing such as cement factories cause deforestation. In the mountains building hotels, monasteries and trekking trails cause deforestation while timber-smuggling into the Tibet Autonomous Region and over-grazing cause degradation.

Boundaries

• Total: 2,926 km
• Border countries: China 1,236 km, India 1,690 km

Border crossings with India

While India and Nepal have an open border with no restrictions on movement of their citizens on either side, there are 23 checkpoints for trade purposes. These are listed in counterclockwise order, east to west. The six in italics are also used for entry/exit by third country nationals.

Border crossings with Tibet Autonomous Region, China

These are listed west to east. Third country nationals cross at Tatopani and in guided groups at Simikot/Hilsa. The Mustang crossing is mainly used by traders.

See also

• Nepal
• List of mountains in Nepal

References

External links

•  This article incorporates public domain material from websites or documents of the Library of Congress Country Studies.
•  This article incorporates public domain material from the CIA World Factbook document "2005 edition".
• Atlas of Nepal
• Nepal Encyclopedia Geopolitical category
• Brief and Concise Geography of Nepal