The 'Kosi River' or 'Kośi River', along with its tributaries, drains part of
Tibet including the
Mount Everest region as well as the eastern one third of
Nepal. The river is joined by major tributaries approximately 48 km north of the Indian-Nepalese frontier, breaking into more than twelve distinct channels with shifting courses due to flooding.
[1][2] Over the last 200 years, the Kosi River has shifted over 120 km from east to west.
[3] Flooding in India has extreme effects. India is second in the world after
Bangladesh in deaths due to flooding , accounting for one fifth of global flooding deaths. The Kosi River (The Sorrow of Bihar) is one of two major tributaries draining the plains of north
Bihar, the most flood-prone area of India
[4]
Formerly 'Kauśiki' (named after sage Viśvāmitra because Viśvāmitra is said to have attained the status of Vedic or
Rishi on its banks; Viśvāmitra was descendant of sage Kuśika and was called Kauśika in Rgveda), in
Nepal and
Bihar in northern
India is a major tributary of the
Ganges River (one major tributary of Kosi is Arun which has major part of its journey in
Tibet ). This river is mentioned in the epic
Mahabharata as Kauśiki. Seven Kosis join together to form the
Saptakoshi River which is popularly known as the Kosi.
From Kāthmāndu, there is a road to some distance followed by trekking paths to Mt Everest, which crosses four major tributaries of Kosi. Nāmche Bāzār near Tibet border in Nepal (near southern base camp of Mt Everest) is the major tourist centre in the mountaineous part of Kosi belt. Birātnagar in Nepal, and Purnia and Katihār in India are major cities in Kosi Plains. Kamlā, Bāghmati (Kareh) and Budhi Gandak are major tributaries of Kosi in India, besides minor tributaries like Bhutahi Balān.
Geography
In Nepal the Kosi lies to the west of
Kanchenjunga. It has seven major tributaries:
Sun Kosi,
Tama Kosi or Tamba Kosi,
Dudh Kosi,
Indravati,
Likhu,
Arun and
Tamore or Tamar.
Dudh Kosi joins the
Sun Kosi at the Nepalese village of
Harkapur. At Triveni Sun Kosi is joined by Arun and Tamar, after which the river is called Sapta Kosi. At in Nepal, it descends from the mountains and it then called simply Kosi. These tributaries encircle Mt Everest from all sides and are fed by world's highest glaciers. Kosi has an average waterflow of 1564 cubic metres per second (55k cft per second). During peak floods, it increases to 18 times over.
The Kosi river fan located in the northern part of India (in north east Bihar or eastern
Mithila) is one of the largest alluvial cones built by any river in the world. This 180 km long and 150 km wide alluvial cone shows evidence of lateral shift exceeding 140 km during the past 250 years. The Kosi alluvial cone and its adjoining area has been studied in detail by remote sensing techniques. The data have been integrated with the available geological and geophysical information to decipher the causes responsible for the lateral shift of such a high magnitude fan. A satellite image shows the old palaeo-channels of the Kosi river with its former (prior to 1731) confluence with the
Mahananda River north of
Lava.
[5]
Fauna
Gangetic River Dolphin , locally known as ''sons'' in Bihar, is an endangered specie (fresh water dolphin).
★
Gangetic River Dolphin (Platanista gangetica)- Rapidly diminishing
[1]
Formerly Kosi basin was heavily forested and hosted all types of wild fauna, but now only the mountaneous regions in Nepal have forests with wild fauna.
The sorrow of Bihar
Kosi or Milk River is known as the “'Sorrow of
Bihar'” when it flows from
Nepal to
India, as it has caused widespread human suffering in the past due to flooding and very frequent change in course
[2] [3] [4]. It is also the life line of the Mithila region of Bihar and forms the basis of folklore of the region.
Books with Kosi as Folklore
★
[6] -
Maithili Short Story collection on the village life of
Mithila on the banks of the Kosi and its tributaries.
1994.
Bhubaneswar. By
Binod Bihari Verma.
[7]
Notes
External links
★
GIS in Flood Hazard Mapping: a case study of Kosi River Basin, India