Geography of Nepal
measures about along its Himalayan axis by across. It has an area of.
Nepal is landlocked by China's Tibet Autonomous Region to the north and India on other three sides. West Bengal's narrow Siliguri Corridor separate Nepal and Bangladesh. To the east are Bhutan and India.
Nepal has a very high degree of geographic diversity and can be divided into three main regions: Terai, Hilly, and Himal. The Terai region, covering 17% of Nepal's area, is a lowland region with some hill ranges and is culturally more similar to parts of India. The Hilly region, encompassing 68% of the country's area, consists of mountainous terrain without snow and is inhabited by various indigenous ethnic groups. The Himal region, covering 15% of Nepal's area, contains snow and is home to several high mountain ranges, including Mount Everest, the world's highest peak.
Nepal, with elevations ranging from less than 100 metres to over 8,000 metres, has eight climate zones from tropical to perpetual snow. The majority of the country's population resides in the tropical and subtropical climate zones. The tropical zone, below 1,000 metres, experiences frost less than once per decade and is suitable for growing various fruits and crops. The subtropical climate zone, from 1,000 to 2,000 metres, is the most prevalent and suitable for growing rice, maize, millet, wheat, and other crops. The temperate climate zone, from 2,000 to 3,000 metres, occupies 12% of Nepal's land area and is suitable for cold-tolerant crops. The subalpine, alpine, and nival zones have progressively fewer human settlements and agricultural activities.
Seasons are divided into a wet season from June to September and a dry season from October to June. The summer monsoon can cause flooding and landslides, while the winter monsoon is marked by occasional rainfall and snowfall. The diverse elevation results in various biomes, including tropical savannahs, subtropical and temperate forests, montane grasslands, and shrublands.
Nepal has three categories of rivers: the largest systems, second category rivers, and third category rivers. These rivers can cause serious floods and pose challenges to transportation and communication networks. River management involves addressing flooding, sedimentation, and sustainable water sources for irrigation. Building dams in Nepal is controversial due to seismic activity, glacial lake formation, sedimentation rates, and cross-border equity issues between India and Nepal.
Nepal's land cover is dominated by forests, which cover 39.09% of the country's total geographical area, followed by agriculture areas at 29.83%. The hill region constitutes the largest portion of Nepal, with significant cultivated lands and natural vegetation. Forests in Nepal face deforestation due to over-harvesting of firewood, illegal logging, clearing for agriculture, and infrastructure expansion. As of 2010, 64.8% of the forested area in Nepal is covered by core forests of more than 500 ha in size. Deforestation and degradation are driven by multiple processes, including firewood harvesting, construction, urban expansion, and illegal logging.
Nepal has consistently been ranked as one of the most polluted countries in the world.
Landform regions
For a country of its size, Nepal has tremendous geographic diversity. It rises from as low as elevation in the tropical Terai—the northern rim of the Gangetic Plain, through beyond the perpetual snow line to 90 peaks over including Earth's highest. In addition to the continuum from tropical warmth to cold comparable to polar regions, average annual precipitation varies from as little as in its narrow proportion of the rainshadow north of the Himalayas to as much as on windward slopes, the maximum mainly resting on the magnitude of the South Asian monsoon.Forming south-to-north transects, Nepal can be divided into three belts: Terai, Pahad and Himal. In the other direction, it is divided into three major river systems, east to west: Koshi, Gandaki/Narayani and Karnali, all tributaries of the Ganges river. The Ganges-Yarlung Zangbo/Brahmaputra watershed largely coincides with the Nepal-Tibet border, save for certain tributaries rising beyond it.
Himal
Himal Region is a mountainous region containing snow.The Mountain Region begins where high ridges begin substantially rising above into the subalpine and alpine zone which are mainly used for seasonal pasturage. By geographical view, it covers 15% of the total area of Nepal. A few tens kilometres further north the high Himalaya abruptly rise along the Main Central Thrust fault zone above the snow line at. Some 90 of Nepal's peaks exceed and eight exceed including Mount Everest at and Kanchenjunga at.
There are some 20 subranges including the Kanchenjunga massif along with the Mahalangur Himal around Mount 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
The main watershed between the Brahmaputra and the Ganges system actually lies north of the highest ranges. Alpine, often semi-arid valleys—including Humla, Jumla, Dolpo, Mustang, Manang and Khumbu—cut between Himalayan sub ranges 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 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.
Hilly
Hilly Region is a mountain region which does not generally contain snow. It is situated to the south of the Himal Region. This region begins at the Lower Himalayan Range, where a fault system called the Main Boundary Thrust creates an escarpment high, to a crest between. It covers 68% of the total area of Nepal.These steep southern slopes are nearly uninhabited, thus an effective buffer between languages and culture in the Terai and Hilly. 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 urbanised 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 urbanised Pahari.
Other indigenous Janajati ethnic groups -— natively speaking highly localised Tibeto-Burman languages and dialects -— populate hillsides up to about. 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 until international pressure persuaded the government to outlaw it in 1976. There is increasing reliance on animal husbandry with elevation, using land above for summer grazing and moving herds to lower elevations in winter. Grain production has not kept pace with population growth at elevations above where colder temperatures inhibit double cropping. Food deficits drive emigration out of the Pahad in search of employment.
The Hilly ends where ridges begin substantially rising out of the temperate climate zone into subalpine zone above.
Terai
Terai is a low land region containing some hill ranges. Looking out for its coverage, it covers 17% of the total area of Nepal. The Terai 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. Industrialisation based on agricultural products such as jute began in the 1930s and infrastructure such as roadways, railways and electricity were extended across the border before it reached Nepal's Pahad region.The Outer Terai is culturally more similar to adjacent parts of India's Bihar and Uttar Pradesh than to the Pahad of Nepal. Nepali is taught in schools and often spoken in government offices, however, the local population mostly uses Maithali, Bhojpuri and Tharu languages.
The Outer Terai ends at the base of the first range of foothills called the Chure Hills or Churia. This range has a densely forested skirt of coarse alluvium called the Bhabar. 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.
Above the Bhabar belt, the Chure Hills rise to about with peaks as high as, steeper on their southern flanks because of faults are 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 Chure, there are dūn valleys called Inner Terai. 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 Pahad begin at a higher range of foothills called the Lower Himalayan Range.