Sunkoshi River

Last updated

Sunkoshi
The Friendship Bridge connecting China with Nepal.jpg
The Sino-Nepal Friendship Bridge over Bhote Koshi at Kodari
Location
CountryTibet, Nepal
Physical characteristics
Source 
 • location Choukati, Nepal
 • coordinates 27°45′23″N86°00′11″E / 27.7563°N 86.0031°E / 27.7563; 86.0031
 • elevation2,400 m (7,900 ft)
2nd source 
 • location Nyalam County, Tibet
 • coordinates 28°27′09″N86°18′24″E / 28.4525°N 86.3067°E / 28.4525; 86.3067
 • elevation5,300 m (17,400 ft)
Mouth  
 • location
Confluence with Arun and Tamur to form Saptkoshi at Trivenighat, Nepal
 • coordinates
 26°54′37″N87°09′41″E / 26.9102°N 87.1613°E / 26.9102; 87.1613
 • elevation
640 m (2,100 ft) [1]
Basin features
River system Koshi River
Tributaries 
 • left Tamba Koshi, Likhu Khola, Dudh Koshi
 • right Bhote Koshi, Indravati River

The Sunkoshi, also spelt Sunkosi, is a river that is part of the Koshi or Saptkoshi River system in Nepal. Sunkoshi has two source streams, one that arises within Nepal in Choukati, and the other more significant stream that flows in from Nyalam County in the Tibet region of China. [1] The latter is called Bhote Koshi in Nepal and Matsang Tsangpo in Tibet. [2] [lower-alpha 1] Due to the significant flows from Bhote Koshi, the Sun Koshi river basin is often regarded as a trans-border river basin. [1] [5]

Contents

River course

Map showing the course of Sun Koshi (AMS, 1955) Map India and Pakistan 1-250,000 Tile NG 45-2 Mount Everest.jpg
Map showing the course of Sun Koshi (AMS, 1955)

The Sunkoshi's headwaters are located in the Zhangzangbo Glacier in Tibet. [6] Both Sunkoshi and Bhote Koshi river courses together form one basin that covers an area of about 3,394 km2 (1,310 sq mi). [1]

The Indravati meets the Sunkoshi at Dolaghat, up to where it is followed by the Arniko Rajmarg. [7] From there, the Sunkoshi flows eastwards through the valley formed between the Mahabharat Range and the Himalayas. [1] The Tamakosi, Likhu, Dudhkosi, Arun and Tamor are its left tributaries and Indravati is the right tributary.

The average annual flow is 2.2 x 1010 m3. The average sediment load is 5.4 x 107 m3. [8]

The Tamur and the Arun rivers join the Sunkoshi at Tribenighat to form the Saptkoshi, which flows through the Chatra Gorge across the Mahabharat Range on to the Gangetic plain. [9] There are also a few smaller tributaries of the Sunkoshi, such as Rosi Khola, Junga Khola, and Sapsu Khola.[ citation needed ]

Names and etymology

Nepali : सुनकोशी

In Nepali language, the word "sun" means gold and golden; [10] and the word "kosi" means river. [11]

Koshi River system

The Koshi River drains eastern Nepal. It is also known as Saptkoshi River because of the seven rivers joining in east-central Nepal to form this river. The main rivers forming the Koshi River system are Sunkoshi, Indravati, Tamba Koshi, Bhote Koshi, Dudh Kosi, Arun and Tamur Rivers. The Saptkoshi River flows through the Chatra Gorge in a southerly direction into northern Bihar and joins the Ganges. [9] [12]

The Sunkoshi contributes about 44% of the total water of the Saptakoshi, the Arun 37% and the Tamur 19%. [13]

Infrastructures

Hazards

In July 1981, a sudden ice avalanche caused a Glacial Lake Outburst Flood in the moraine-dammed Zhangzangbu-Cho Lake in the headwaters of the Poiqu in Tibet. The ensuing debris flow destroyed bridges, and sections of both the Arniko and the Nepal–China highways. [6]

On 2 August 2014, a landslide at Jure blocked the river downstream from Barabise and created a large lake that submerged a hydropower station. This huge rockslide of approximately 5,000,000 m3 (180,000,000 cu ft) blocked the Sunkoshi River upstream of Jure village. This landslide killed approximately 155 people, destroyed approximately 120 houses completely and 37 partially. [16] The area was declared a flood crisis zone, and local communities were evacuated. Power supply was interrupted, and the Arniko Highway blocked. [17]

Water sports

The Sunkoshi is used for both rafting and intermediate kayaking. It has grade III-IV rapids. The most common put in point of a Sunkoshi river trip is Dolaghat, at an elevation of 620 m (2,030 ft) and it ends at the Chatra Gorge at 115 m (377 ft), a distance of around 272 km (169 mi). [18]

The first successful descent of the Sunkoshi was made in late September 1970 by Daniel C. Taylor, Terry Bech, Cheri Bremer-Kamp, and Carl Schiffler. They entered the river at Dolaghat and exited at the Nepal-India border. Their expedition took four days. [19] Prior to this successful trip, there are four known unsuccessful attempts to descend the river, and one unsuccessful attempt to ascend the river in a jet boat under the leadership of Edmund Hillary. [20]

Notes

  1. ↑ An alternative Tibetan name Bö Chu (Tibetan: བོད་ཆུ, Wylie: bod chu), also spelt Po Chu or Poi Chu, is also used in sources. [3] [4] It would appear to be a literal translation of Bhote Kosi ("Tibetan river").

Related Research Articles

<span class="mw-page-title-main">Geography of Nepal</span> Geographical features of Nepal

Nepal measures about 880 kilometers (547 mi) along its Himalayan axis by 150 to 250 kilometers across. It has an area of 147,516 km2 (56,956 sq mi).

<span class="mw-page-title-main">Bagmati River</span> River in Nepal

The Bagmati River flows through the Kathmandu valley of Nepal, separating the cities of Kathmandu and Patan, before flowing through Madesh Province of southern Nepal and joining the Kamla River in the Indian state of Bihar. It is considered holy by both Hindus and Buddhists. A number of Hindu temples are located on its banks.

<span class="mw-page-title-main">Dudh Koshi</span> River in Nepal

Dudh Koshi is a river in eastern Nepal. It is the highest river in terms of elevation.

<span class="mw-page-title-main">Tamur River</span> River in Nepal

The Tamor River is a major river in eastern Nepal, which begins around Kanchenjunga. The Tamor and the Arun join the Sun Koshi at Tribenighat to form the giant Saptakoshi which flows through Mahabharat Range on to the Gangetic plain.

Kosi may refer to:

<span class="mw-page-title-main">Taplejung District</span> District in Koshi Province, Nepal

Taplejung District is one of 77 districts of Nepal and one of the 14 districts of Koshi Province. It is located deep in the Himalayas in Eastern Nepal with Tibet to the north across the Himalayas. Taplejung is the third largest district of Nepal.

<span class="mw-page-title-main">Kosi River</span> River in Tibet, Nepal, and India

The Kosi or Koshi is a transboundary river which flows through China, Nepal and India. It drains the northern slopes of the Himalayas in Tibet and the southern slopes in Nepal. From a major confluence of tributaries north of the Chatra Gorge onwards, the Kosi River is also known as the Saptakoshi for its seven upper tributaries. These include the Tamur River originating from the Kanchenjunga area in the east and Arun River and the Sun Kosi from Tibet. The Sun Koshi's tributaries from east to west are the Dudh Koshi, Likhu Khola, Tamakoshi River, Bhote Koshi and Indravati. The Saptakoshi crosses into northern Bihar, India where it branches into distributaries before joining the Ganges near Kursela in Katihar district. The Kosi is the third-largest tributary of the Ganges by water discharge after the Ghaghara and the Yamuna.

<span class="mw-page-title-main">Bhotekoshi River</span> River in Nepal

Bhote Koshi in Nepal and Poiqu in Tibet is the name given to the upper course of the Sun Kosi river. It is part of the Koshi River system in Nepal.

<span class="mw-page-title-main">Arun River (China–Nepal)</span> River in China and Nepal

The Arun River is a trans-boundary river and is part of the Kosi or Sapt Koshi river system in Nepal. It originates in Tibet Autonomous Region of the People's Republic of China where it is called the Phung Chu or Bum-chu.

<span class="mw-page-title-main">Bhimeshwar</span> Municipality in Bagmati Province, Nepal

Bhimeshwar,, is a municipality in north-eastern Nepal and the headquarters of Dolakha District in Bagmati Province that was established in 1997 by merging the former Village development committees Charikot, Dolakha Town, Makaibari and Mati. At the time of the 2011 Nepal census, it had a population of 32,486 people living in 8,639 individual households. The town is located at an altitude of 1,554 metres (5,101 feet). The name of the district Dolakha came from Dolakha Town situated north-east of the headquarters Charikot Bazaar.

<span class="mw-page-title-main">Araniko Highway</span> Highway in central hilly Nepal

The Araniko Highway connects Kathmandu with Kodari, 112.83 kilometres (70.11 mi) northeast of the Kathmandu Valley, on the Nepal-China border. It is among the most dangerous of highways in Nepal due to extremely steep slopes on each side of the road from Barabise onwards; massive landslides and bus plunges are not uncommon, especially after rains. At the Sino-Nepal Friendship Bridge, it connects with China National Highway 318 to Lhasa, and eventually to Shanghai.

<span class="mw-page-title-main">Kamala River</span> River in Nepal and Bihar

The Kamala River originates in Nepal and flows through the Indian state of Bihar.

<span class="mw-page-title-main">Indravati River (Nepal)</span> River in Nepal

The Indravati River in Nepal is a tributary of the Sun Koshi River. It used to be called "Melamchi" or "Melamchu" until the 19th century.

<span class="mw-page-title-main">Barun River</span> River in Nepal

The Barun River is a tributary of the Arun River and is part of the Kosi river system in Nepal.

<span class="mw-page-title-main">Trishuli River</span> River

The Trishuli River is one of the major tributaries of the Narayani River basin in central Nepal. The river is formed by the merger of Kyirong Tsangpo and Lende Khola originating in Gyirong County of Tibet, which join together near the Rasuwa Gadhi on the Nepal–Tibet border. The valley of the river used to be the traditional trade route between the Kathmandu Valley and Tibet.

<span class="mw-page-title-main">Nyalam Tong La</span>

Nyalam Tong La or Yakrushong La is a mountain pass in China on the Matsung Tsangpo-Phung Chhu watershed divide where the Friendship Highway connecting Kathmandu, Nepal and Lhasa, Tibet crosses at 5,150 metres (16,900 ft) elevation.

The Chatra Gorge is a canyon cut by the Kosi River across the Mahabharat Range in Nepal.

<span class="mw-page-title-main">Koshi Province</span> Province of Nepal

Koshi Province is the autonomous easternmost province adopted on 20 September 2015 by Constitution of Nepal. The province is rich in natural resources, tourist attractions, recreational activities, and natural beauty. The province covers an area of 25,905 km2 (10,002 sq mi), about 17.5% of the country's total area. With the industrial city of Biratnagar as its capital, the province includes major eastern towns of Birtamod, Sundar Haraincha, Damak, Dharan, Itahari, Triyuga Municipality and Mechinagar, and the Mount Everest, Kangchenjunga and Ama Dablam. Koshi River, the largest river of the nation, is the province's western boundary. Under the First-past-the-post voting system issued by the Constituency Delimitation Commission, Nepal, the province hosts 28 parliamentary seats and 56 provincial assembly seats.

Landslides are triggered in Nepal due to a combination of steep mountains and unstable soils. The risk of the landslide is high in the monsoon season due to the lubrication of soil in the slope by moisture. Another important factor triggering the landslide is earthquakes. When landslide occurs near the river, it can block the river causing a damming effect. Damming could also occur due to rock-slides. Such dams are unstable and can cause flooding if not breached in controlled manner. Below is a list of dams formed due to landslides and their impacts in Nepal Annually, 593 natural disaster occurs in average and quite a few of them are related to the damming by landslides and about 13% of fatality is directly related to the landslide and Landslides Dammed Outburst Flood (LDOF).

References

  1. 1 2 3 4 5 Shrestha, A. B., Eriksson, M., Mool, P., Ghimire, P., Mishra, B. & Khanal, N. R. (2010). "Glacial lake outburst flood risk assessment of Sun Koshi basin, Nepal". Geomatics, Natural Hazards and Risk. 1 (2): 157–169. doi: 10.1080/19475701003668968 . S2CID   129446680.{{cite journal}}: CS1 maint: multiple names: authors list (link) (See especially Figure 1).
  2. ↑ Dorje, Gyurme (2004), Footprint Tibet Handbook with Bhutan (3rd ed.), Bath: Footprint Handbooks, p. 321, ISBN   1-903471-30-3 – via archive.org
  3. ↑ Yamada, T; Sharma, C.K. (1993). "Glacier lakes and outburst floods in the Nepal Himalaya" (PDF). International Association of Hydrological Sciences. pp. 319–330. Archived from the original (PDF) on 20 March 2020.
  4. ↑ Su, Pengcheng; Liu, Jingjing; Li, Yong; Liu, Wei; Wang, Yang; Ma, Chun; Li, Qimin (11 November 2021). "Changes in glacial lakes in the Poiqu River basin in the central Himalayas". Hydrology and Earth System Sciences. 25 (11): 5879–5903. doi: 10.5194/hess-25-5879-2021 . eISSN   1607-7938. the Poiqu River (Bhote Koshi River), a tributary of the Sun Koshi River ... The Poiqu River (known as the Bhotekoshi River in Nepal) is the boundary river between China and Nepal
  5. ↑ Bhattarai, Keshav; Conway, Dennis (23 November 2020). Contemporary Environmental Problems in Nepal: Geographic Perspectives. Springer Nature. p. 495. ISBN   978-3-03-050168-6.
  6. 1 2 Mool, P. K.; Joshi, S. P.; Bajracharya, S. R. (2001). Glacial Lake Outburst Floods and Damage in the Country. Pages 121–136 in: Inventory of Glaciers, Glacial Lakes and Glacial Lake Outburst Floods: Monitoring and Early Warning Systems in the Hindu Kush-Himalayan Region, Nepal. International Centre for Integrated Mountain Development, Kathmandu.
  7. ↑ Dorje, G. (1999). Tibet Handbook: with Bhutan. Bath: Footprint Handbooks. ISBN   9781900949330.
  8. ↑ Kattelmann, R. (1991). "Hydrologic regime of the Sapt Kosi basin, Nepal" (PDF). Hydrology for Water Management of Large River Basins (Proceedings of the Vienna Symposium). 201: 139–148.
  9. 1 2 Sharma, U. P. (1996). Ecology of the Koshi river in Nepal-India (north Bihar): a typical river ecosystem. In: Jha, P. K., Ghimire, G. P. S., Karmacharya, S. B., Baral, S. R., Lacoul, P. (eds.) Environment and biodiversity in the context of South Asia. Proceedings of the Regional Conference on Environment and Biodiversity, 7–9 March 1994, Kathmandu. Ecological Society, Kathmandu. Pp 92–99.
  10. ↑ Turner, R. L. (1931). "sun". A Comparative and Etymological Dictionary of the Nepali Language. K. Paul, Trench, Trubner, London.
  11. ↑ Turner, R. L. (1931). "kosi". A Comparative and Etymological Dictionary of the Nepali Language. K. Paul, Trench, Trubner, London.
  12. ↑ Negi, S. S. (1991). "Kosi River System". Himalayan Rivers, Lakes, and Glaciers. New Delhi: Indus Publishing Company. pp. 89–90. ISBN   9788185182612.
  13. ↑ Rao, K. L. (1995). India's Water Wealth. Hyderabad: Orient Longman Ltd. p. 70. ISBN   9788125007043.
  14. ↑ Bhattarai, D. (2009). "Sunkosi–Kamala Multi–purpose Project". In Dhungel, D. N.; Pun, S. B. (eds.). The Nepal–India Water Relationship: Challenges. Springer Science & Business Media. pp. 92–93. ISBN   9781402084034.
  15. ↑ Gajurel, D. (2004). "High Dam Planned for Nepal's Sapta Koshi River". Environment News Service. Retrieved 14 May 2010.
  16. ↑ Jaboyedoff, M.; Leibundgut, G.; Penna, I.; Dahal, R. K.; Sevkota, S.; Sudmeier, K. (2015). Characterization of the Jure (Sindhupalchok, Nepal) Landslide by TLS and field investigations. European Geosciences Union General Assembly 12–17 April 2015. Vienna, Austria: European Geosciences Union. p. 11858. Bibcode:2015EGUGA..1711858J.
  17. ↑ Shrestha, A. B.; Khanal, N. R.; Shrestha, M.; Nibanupudi, H. K.; Molden, D. (2014). Eye on the Sun Koshi Landslide: Monitoring and Infrastructure Planning Key to Minimizing Scale of Disasters (PDF) (Report). Kathmandu: International Centre for Integrated Mountain Development.
  18. ↑ Woodhatch, T. (1999). Nepal Handbook. p. 167, Footprint Handbooks, Augusta ISBN   0658000160
  19. ↑ Taylor-Ide, D. (1995). "Something Hidden Behind the Ranges." San Francisco: Mercury House
  20. ↑ Taylor, D. C. "Yeti: An Ecology of a Mystery." New Delhi: Oxford University Press, pp. 119-130.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.