Jump to content

2008 Bihar flood: Difference between revisions

From Wikipedia, the free encyclopedia
Browse history interactively
← Previous editNext edit →
Content deleted Content added
VisualWikitext
Octopet (talk | contribs)
694 edits
→Incident: CE/tag
Octopet (talk | contribs)
694 edits
Line 18: Line 18:


==Background==
==Background==
The [[Kosi River]]'s upper basin in southern [[Tibet]] and eastern [[Geography of Nepal|Nepal]] drains some 60,000&nbsp;km² of mountainous terrain <ref>[http://iahs.info/redbooks/a201/iahs_201_0139.pdf Kattelman, Richard (1991) Hydrological Regime of the Sapt Kosi Basin, Nepal.]</ref>, a region that tectonic forces are elevating by about 1&nbsp;cm a year.<ref>[http://www.terrapub.co.jp/journals/EPS/pdf/5210/52100735.pdf Xu, Liu, Song, Jiang & Shi, GPS measurements of present-day uplift in the Southern Tibet]</ref>. If erosion keeps pace with uplift completely, some 600 million cubic meters of sediment would be washing downstream in an average year, but empirical measurements of the river's sediment load have yielded estimates of 100 million cubic meters annually,<ref>[http://www.gisdevelopment.net/application/geology/geomorphology/geom0002.htm Srivastava, Ajay. Tectonic Zonation using Multi-Criteria Decision-Making (MCDM) Techniques: A case study of Kosi Fan, India.]</ref>. which clearly shows that the area is rising.
The [[Kosi River]]'s upper basin in southern [[Tibet]] and eastern [[Geography of Nepal|Nepal]] drains some 60,000&nbsp;km² of mountainous terrain <ref>[http://iahs.info/redbooks/a201/iahs_201_0139.pdf Kattelman, Richard (1991) Hydrological Regime of the Sapt Kosi Basin, Nepal.]</ref>, a region that tectonic forces are elevating by about 1&nbsp;cm a year.<ref>[http://www.terrapub.co.jp/journals/EPS/pdf/5210/52100735.pdf Xu, Liu, Song, Jiang & Shi, GPS measurements of present-day uplift in the Southern Tibet]</ref>. If erosion keeps pace with geologic uplift, an estimated 600 million cubic meters of sediment is potentially carried downstream in an average year. However, empirical measurements of the river's sediment load have yielded estimates of 100 million cubic meters annually,<ref>[http://www.gisdevelopment.net/application/geology/geomorphology/geom0002.htm Srivastava, Ajay. Tectonic Zonation using Multi-Criteria Decision-Making (MCDM) Techniques: A case study of Kosi Fan, India.]</ref>. indicates that the area is rising.


River gradient ranges from more than 10 meters/km for major upper tributaries in the mountains to as little as 6&nbsp;cm/km as the lower Kosi nears the Ganges <ref>Sharad Jain, Pushpendra Agarwal, Vijay Singh (2007) Hydrology and Water Resources of India. (Netherlands:Springer).</ref> As the gradient decreases on the plains, current slows and turbulence that holds sediments in suspension diminishes. Sediments settle out and are deposited on the riverbed. This process eventually raises any given channel above surrounding terrain, upon which the river breaks out seeking lower terrain, which it again proceeds to elevate by deposition. Thus a cone-shaped [[alluvial fan]] evolves; . The [[Kosi]] [[alluvial fan]] is one of the largest in the world, covering some 15,000&nbsp;km² and extending 180&nbsp;km from the outermost foothills of the [[Himalaya]] to the [[Ganges]] river valley.<ref>[http://www.geo.tu-freiberg.de/oberseminar/os07_08/ralf_dedow.pdf Dedow, Ralf. Megafans in younger orogens.]</ref>.
River gradient ranges from more than 10 meters/km for major upper tributaries in the mountains to as little as 6&nbsp;cm/km as the lower Kosi nears the Ganges <ref>Sharad Jain, Pushpendra Agarwal, Vijay Singh (2007) Hydrology and Water Resources of India. (Netherlands:Springer).</ref> As the gradient decreases on the plains, current slows and turbulence that holds sediments in suspension diminishes. Sediments settle out and are deposited on the riverbed. This process eventually raises any given channel above surrounding terrain, upon which the river breaks out seeking lower terrain, which it again proceeds to elevate by deposition. Thus a cone-shaped [[alluvial fan]] evolves; . The [[Kosi]] [[alluvial fan]] is one of the largest in the world, covering some 15,000&nbsp;km² and extending 180&nbsp;km from the outermost foothills of the [[Himalaya]] to the [[Ganges]] river valley.<ref>[http://www.geo.tu-freiberg.de/oberseminar/os07_08/ralf_dedow.pdf Dedow, Ralf. Megafans in younger orogens.]</ref>.

Revision as of 22:55, 7 March 2011

2008 Bihar flood
Flooded north Bihar, India
Date18 August 2008 - Present
Locationnorthern Bihar, India and Nepal
Deaths434 [1] (Dead bodies found till 27th November 2008)

The 2008 Bihar flood was one of the most disastrous floods in the history of the Indian state of Bihar. A breach in the Kosi embankment near the Indo-Nepal border (at Kusha in Nepal) occurred on 18 August, 2008. The river changed course and inundated areas which hadn't experienced floods in many decades.[2]. The flood affected over 2.3 million people in the northern part of Bihar.[3].

Incident

See also: Kosi embankment and Breaches in Kosi embankment

On 18 August 2008, heavy monsoon rains and poor maintenance caused a breach in the Kosi embankment. Water passed through the breach at an estimated 129,800 cumecs (cubic meters per second), inundating hundreds of villages in northern Bihar. The flood submerged most of the Kosi alluvial fan area, which is very fertile and has dense agrarian population. The flood also resulted in substantial loss of life and property in the south east tarai region of Nepal. More than 2.5 million people were affected.[citation needed]

Background

The Kosi River's upper basin in southern Tibet and eastern Nepal drains some 60,000 km² of mountainous terrain [4], a region that tectonic forces are elevating by about 1 cm a year.[5]. If erosion keeps pace with geologic uplift, an estimated 600 million cubic meters of sediment is potentially carried downstream in an average year. However, empirical measurements of the river's sediment load have yielded estimates of 100 million cubic meters annually,[6]. indicates that the area is rising.

River gradient ranges from more than 10 meters/km for major upper tributaries in the mountains to as little as 6 cm/km as the lower Kosi nears the Ganges [7] As the gradient decreases on the plains, current slows and turbulence that holds sediments in suspension diminishes. Sediments settle out and are deposited on the riverbed. This process eventually raises any given channel above surrounding terrain, upon which the river breaks out seeking lower terrain, which it again proceeds to elevate by deposition. Thus a cone-shaped alluvial fan evolves; . The Kosi alluvial fan is one of the largest in the world, covering some 15,000 km² and extending 180 km from the outermost foothills of the Himalaya to the Ganges river valley.[8].

Floodwater naturally spread out over the surface of this cone. Flows over 25,000 cumecs (cubic meters per second) have been measured where the Kosi exits the Himalayan foothills, enough to create a flow of water 30 km wide [9]. At this rate, in one week enough water would accumulate to cover the entire megafan to a depth of 1.5 meters. Through these approximations, the severity of this flood and the plight of those living it its path can begin to be imagined.

Potential flood control measures include upstream reservoirs in the mountains that can also serve irrigation needs and produce hydroelectric power, but in Nepal these are still mainly in planning stages.[10]. The flood control measures mainly consists of downstream embankments meant to confine the river to a fixed channel, hoping that faster flow along this channel would carry high flows away and keep sediments in suspension.

Silt deposition near Kosi embankment at Navbhata, Saharsa, Bihar, India

On 18 August 2008, one of the man made embankments failed. The river then abandoned the prescribed western channel for an old channel near the center of its alluvial fan, but also spread out widely and inundated towns, villages and cultivated fields on the densely populated alluvial fan. The flood covered a vast area and disrupted the lives of 3 million people including approximately 1000 deaths.[11] Recurrent flooding on the lower Kosi contributes largely to India's history of more flood deaths than in any other country, except Bangladesh, earning Kosi the epithet "The Sorrow of Bihar".[12].

Affected areas

Flooding occurred around the Kosi River valley, affecting over 2.3 million people in northern Bihar, in the districts of in districts of Supaul, Araria, Saharsa, Madhepura and Purnea.[13].[3] The worst affected districts included Madhepura, Bhagalpur, Araria and West Champaran.The south east tarai region of Nepal was also affected.

Death toll rose from Indian floods as around 1000 people have been killed in monsoon rains.[11][14] Villagers ate raw rice and flour mixed with polluted water in Bihar, amid hunger and diseases. Supaul district was the worst-hit by floods and surging waters swamped 1,000 square kilometres (247,000 acres) of farmlands, destroying wheat and paddy crops.[15]

Relief Work

In response to the flood, Chief Minister of Bihar Nitish Kumar met Prime Minister Manmohan Singh to seek his help in dealing with the "catastrophe" [16]. Relief work was carried with Indian Air Force helicopters dropping relief materials in the worst hit districts.

New York Times reported that it is the worst flood in the area in 50 years. India's Prime Minister Manmohan Singh declared a “national calamity” on 28 August and the government earmarked $ 230 million in aid for the region.[17] The Indian Army, National Disaster Response Force (NDRF) and non-government organizations operated the biggest flood rescue operation in India in more than 50 years. Mumbai Fire Brigade send its 22 member disaster management team to help in relief work. Many NGOs and organisations have started relief work and are looking for individual donations to help quickly meet the needs of the public.[18]

1 September, describing the floods as a “disaster”, the Dalai Lama had given 10 lakh rupees to the Bihar government for relief work.[19]

The Bihar government has demanded release of Rs 14,500 crore rehabilitation package from the central government for the development of flood ravaged Kosi region.[20] During this flood, the Bihar government returned funds from Gujarat for relief work because of putported differences with the Gujarat Chief Minister, Narendra Modi[21]

Administrative Lapse

SOS fax messages were sent by the engineers at Kosi dam but they were not attended to by the relevant official as he was on leave. No other officer was deputed to act on the fax messages and they have piled upon the bureaucrat's desk. Nitish Mishra, Bihar's disaster management minister acknowledged this and said action would be taken once all this is over.[22]

Flood Information Management System

Recognising the need to have a comprehensive database on flood relief and rehabilitation work, a group of people from Planning Commission, along with a few professionals have started an online Bihar Flood Information management System.[23] The website lists over 70 organisations involved in relief and rehab work in the state and gives their contact details, area of work, collection centres etc. It also has district profiles, details of relief camps and districtwise distribution of NGOs or organisations at work.

See also

References

  1. ^ A report by the Department of disaster management, Government of Bihar
  2. ^ A Dalit watch report on the flood camps in Bihar
  3. ^ a b "Half of Bihar under water, 30 lakh suffer;". CNN IBN. 09/01/2008. Retrieved 2008-09-01. {{cite news}}: Check date values in: |date= (help)
  4. ^ Kattelman, Richard (1991) Hydrological Regime of the Sapt Kosi Basin, Nepal.
  5. ^ Xu, Liu, Song, Jiang & Shi, GPS measurements of present-day uplift in the Southern Tibet
  6. ^ Srivastava, Ajay. Tectonic Zonation using Multi-Criteria Decision-Making (MCDM) Techniques: A case study of Kosi Fan, India.
  7. ^ Sharad Jain, Pushpendra Agarwal, Vijay Singh (2007) Hydrology and Water Resources of India. (Netherlands:Springer).
  8. ^ Dedow, Ralf. Megafans in younger orogens.
  9. ^ [1]
  10. ^ Nayak, Jit Narayan (1996) Sediment management of the Kosi River basin in Nepal.
  11. ^ a b http://www.alertnet.org/db/crisisprofiles/SA_MON.htm
  12. ^ [2]
  13. ^ SITUATION REPORT BIHAR FLOODS 2008
  14. ^ abc.net.au, Death toll rises from Indian floods
  15. ^ reuters.com, Bihar villagers desperate as floods spread
  16. ^ "Bihar flood 'catastrophe'; CM seeks Govt's help". CNN IBN. 2008-08-26. Retrieved 2008-08-26.
  17. ^ nytimes.com, Floods in India May Displace Millions
  18. ^ Ways to donate to help Bihar Flood Victims
  19. ^ Dalai Lama offers prayers and donation for Bihar flood victims
  20. ^ Nitish seeks speedy release of rehab package for Kosi region
  21. ^ "Nitish returns flood aid, BJP hits back at him". IBN Live. 2010-06-20. Retrieved 2010-10-28. {{cite web}}: Italic or bold markup not allowed in: |publisher= (help)
  22. ^ http://www.expressindia.com/latest-news/Floods-have-pushed-Bihar-back-by-50-years/356893/
  23. ^ Bihar Flood Information management System website
Retrieved from "https://en.wikipedia.org/w/index.php?title=2008_Bihar_flood&oldid=417683741"