Floods in Bihar

A view of 2008 Bihar flood
Yearly flood deaths from 1979 to 2008
YearHumanAnimal
2008434845
2007136126
20063631
2005584
20048853272
2003251108
20024891450
2001231565
20003362568
1999243136
1998381187
1997163151
1996222171
19952913742
19949135
1993105420
19924
19915684
19903676
198926
19885229
198713995302
1986134511
19858320
198414390
19833521
19822514
19811811
19806742
1979144

Bihar is India's most flood-prone State, with 76% of the population in the north Bihar living under the recurring threat of flood devastation.[1] According to some historical data, 16.5% of the total flood affected area in India is located in Bihar while 22.1% of the flood affected population in India lives in Bihar.[2] About 68,800 square kilometres (26,600 sq mi) out of total geographical area of 94,160 square kilometres (36,360 sq mi) comprising 73.06% is flood affected. Floods in Bihar are a recurring disaster which on an annual basis destroys thousands of human lives apart from livestock and assets worth millions.[1] The 2013 Flood in Bihar affected more than 5.9 million people in 3,768 villages in 20 districts of the state.[3]

History

Recent Chronology

Recent year in which human death due to flood is more than 100.

Map of floods in India showing North Bihar as a flood-prone area

Reason for flooding

Geographically Nepal is a mountainous region. When heavy rains occur in the mountains of central and eastern Nepal the water flows into the major drainages of Narayani, Bagmati, and Koshi rivers. As these rivers cross into India they flow into the plains and lowlands of Bihar and break their banks. To protect the Koshi River dam as well as the Koshi Barrage Pool's embankments, Indian engineers who are in charge of the dam in Nepal, further open the dam's gates which can cause flooding down river in Bihar. In 2008 during a high flow episode a breach in the East Koshi afflux embankment above the dam occurred and the Koshi river, known for centuries as the Sorrow of Bihar, picked up an old channel it had abandoned over 100 years previously near the border with Nepal and India. Approximately 2.7 million people were affected as the river broke its embankment at Kusaha in Nepal, submerging several districts of Nepal and India. 95% of the Koshi's total flowed through the new course.


Embankments

A recent fact finding report for the Kosi floods of 2008, prepared by a civil society organization by various experts like Dr. Sudhir Sharma, Dr. Dinesh Kumar Mishra, and Dr Gopal Krishna, highlighted that although India has built over 3000 km of embankments in Bihar over the last few decades, the flooding propensity has increased by 2.5 times during the same time period, not to mention that embankments failed during each major flooding event.

The Fact Finding Mission recently released a report titled Kosi Deluge: The Worst is Still to Come, in which it stressed that embankments straitjacket the river. In the case of the Kosi, it found that because of siltation the river bed was in fact several feet higher than the adjoining land. The high and low lands separated by embankments have created a situation where the low lands have become permanently waterlogged. Sixteen per cent of the land mass of north Bihar is subject to permanent waterlogging.

In 1954, when the Bihar flood policy was first introduced, Bihar had approximately 160 km of embankments. At this time, the flood-prone area in the state was estimated to be 2.5 million hectares. Upon the completion of the system of embankments, 3,465 km of embankments had been constructed and were administered by the Water Resources Department (WRD). However, the amount of flood-prone land increased to 6.89 million hectares by 2004.

Deforestation

Deforestation in the catchment area has led to increase in the silt content of the river flow. The total catchment area of the Kosi is 74,030 km2, excluding the catchment areas of its two important tributaries, the Kamla (7,232 km2) and the Bagmati (14,384 km2). These tributaries of the Kosi are important in themselves and are generally dealt with separately. Out of the total catchment of the Kosi, only 11,410 km2 are located in India and the rest (62,620 km2) lie in Nepal and Tibet. The river's catchment area at Triveni in Nepal is 59,550 km2. The average rainfall in the upper catchment of the Kosi is 1,589 mm while in the lower areas it is 1,323 mm. The average annual silt load of the river is 92,400 acre feet (114,000,000 m3).

Farrakha barrage

The period has caused serious interception in the dynamic equilibrium of the river hindering the natural oscillation of the river within its meandering belt. The meandering belt of Ganges in Malda and Murshidabad is 10 km wide. The water level of the Ganges rose about 8 m upstream of the Farakka barrage. The river which flowed in a South Easterly course between Rajmahal and Farakka during early decades of this century has now formed a mighty meander loop concentration to accommodate the additional discharge accumulated due to the barrage. Due to the obstruction caused by the Barrage each year nearly 640 million tonnes of silt is accumulated in the riverbed. In the last three decades this has resulted in the accumulation of nearly 18.56 billion tonnes of silt.

Farrakha barrage has led to following problems upstream of the barrage:

Affected rivers

North Bihar is a playfield of eight major rivers. All these rivers end up in Ganges.

Statistics

Total Affected and Damaged in Bihar due to flood 1979–2006[4][5]
YearDistrictBlocksPanchayatVillageHuman
(in 100,000)		Animal
(in 100,000)		Total Area
(in 100,000 ha)		Cropped area
(in 100,000 ha)		Crop Damaged
(in 100,000 INR)		House AffectedPublic Property Damaged
(in 100,000 INR)
2006146337595910.890.11.810.87706.6318,6378,456.17
200512815621,46421.045.354.61.351,164.505,538305
2004202112,7889,346212.9986.862713.9952,205.64929,773103,049.60
2003241721,4965,07776.0211.9615.086.16,266.1345,2621,035.16
20022562,5048,318160.1852.5119.699.451,149.61419,01440,892.19
2001221941,9926,40590.9111.711.956.526,721.79222,07418,353.78
2000332132,32712,35190.188.098.054.438,303.70343,0913,780.66
1999241501,6045,05765.6613.588.453.0424,203.8891,8135,409.99
1998282602,7398,347134.730.9325.1212.8436,696.68199,6119,284.04
1997261691,9027,04369.6510.1114.716.555,737.66174,3792,038.09
1996291952,0496,41767.336.611.897.347,169.29116,1941,035.70
1995261771,9018,23366.298.159.264.2419,514.32297,7652,183.57
1994211121,0452,75540.1215.036.323.55,616.3333,876151.66
1993181241,2633,42253.526.6815.6411.3513,950.17219,8263,040.86
19928191704145.560.750.760.2558.091,2810.75
1991241371,3364,09648.235.139.84.052,361.0327,324139.93
1990241621,2594,17839.572.78.733.211,818.8811,009182.27
198916746521,82118.790.354.711.65704.887,74683.7
1988231811,6165,68762.340.2110.523.954,986.3214,759150.64
1987303826,11224,518286.6233.2547.525.767,881.001,704,999680.86
1986231891,8286,50975.8XXXX19.187.9710,513.51136,7743,201.99
1985201621,2455,31553.09XXXX7.944.383,129.52103,279204.64
1984232393,20911,154135XXXX30.515.8718,543.85310,4052,717.72
1983221381,2244,06042.41XXXX18.135.782,629.2538,679258.14
1982151101,1123,70846.8145.149.323.239,700.0068,242955.33
1981212012,1387,36769.4774.8312.617.717,213.1975,776XXXX
1980211931,8697,01074.45XXXX17.869.437,608.43118,507XXXX
197913110XXXXXXXX37.38XXXX8.062.741,901.5227,816XXXX

See also

Gallery

References

  1. 1 2 Flood Management Information System - History of Flood in Bihar
  2. ↑ India Water Portal - Bihar Floods 2008
  3. ↑ "Bihar speeds up Flood Relief and Rescue Operations". Retrieved 5 September 2013.
  4. ↑ Disaster Management in Bihar
  5. ↑ Disaster Management in Bihar - Statistics
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