WHY BIHAR SEES FLOOD EVERY YEAR

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Context:  

Bihar is among India's most flood-prone states. The reasons for this are the state's unique geography, and a decades-old solution that has proved short-sighted.

Bihar’s vulnerability

• According to an IIT study, 14 out of 50 most vulnerable districts to climate change in India are in Bihar.
• Bihar is India’s most flood-prone state, with 76 per cent of the population in north Bihar living under the recurring threat of flood devastation.
• Vulnerability: Lack of forest area for the rural population, high yield-variability of food grains, the prevalence of rainfed agriculture, lack of crop insurance, compounding agricultural vulnerability, high sensitivity of the health sector (disease prevalence) are the major drivers of vulnerability for Bihar.
• Fourteen (out of 50 in India) most vulnerable districts to climate change that are in Bihar include  Araria, Kishanganj, Purnia, Jamui, Sheohar, Madhepura, Purbi Champaran, Lakhisarai, Siwan, Sitamarhi, Khagaria, Gopalganj, Madhubani and Buxar.

About 80% (31 out of 38) of the districts in Bihar are among the top 25% most vulnerable districts in the country.

Why is Bihar prone to annual flooding?

Causes of Flooding	Details
Geographical Impact	Nepal's mountainous region experiences heavy rains, which flow into major rivers such as Narayani, Bagmati, and Koshi.  As these rivers cross into India, they tend to break their banks, causing floods in the plains and lowlands of Bihar.
Role of Embankments	India has constructed over 3,000 km of embankments in Bihar, yet the flooding tendency has increased by 2.5 times. These embankments have also led to permanent waterlogging in 16% of north Bihar's land mass due to siltation.
	Kosi Embankment Breach (2008): A breach in the East Koshi afflux embankment caused the river to revert to an old channel it had abandoned over 100 years prior. This breach submerged several districts in both Nepal and India, affecting approximately 15 million people.
	Flood-Prone Areas (1954 vs. 2004): In 1954, when Bihar introduced its flood policy, there were 160 km of embankments, and 2.5 million hectares were flood-prone. By 2004, embankments extended to 3,465 km, but the flood-prone area had grown to 6.89 million hectares.
	Bihar Flood Impact (1954 vs. 2016): In 1954, 2.5 million hectares were flood-affected with 160 km of embankments. By 2016, this area had expanded to 7.295 million hectares after 3,731 km of embankments were constructed.
Farakka Barrage Impact	The Farakka Barrage has caused changes to the river's natural course, resulting in sediment accumulation (640 million tonnes annually), an increased risk of flooding, and reduced flora and fauna, including the Hilsha fish population.
Impact on Ganges	The barrage has led to issues such as the interception of flow, sedimentation, widening of the river, and increased flood frequency. The river upstream has seen water levels rise by 8 meters, with nearly 18.56 billion tonnes of silt accumulating over 30 years.
Upstream Effects of Farakka Barrage	A Central Water Commission (CWC) report stated that the Farakka Barrage impacts areas up to 42 km upstream due to the backwater effect, though Patna is 400 km upstream. Banana plantations between Patna and Bhagalpur were also identified as a contributing factor to Ganga flooding.

Possible Solutions to the Flood Problem

A former vice-chairman of the Bihar State Disaster Management Authority, has emphasized the importance of adopting a dual strategy:

• Structural Measures: These include constructing dams, embankments, and barrages to control river flow and reduce the risk of flooding.
• Non-Structural Measures: These focus on laws, policies, and risk-reduction strategies such as improving flood warning systems.

Discussions regarding a dam on the Kosi River have arisen several times over the years, but progress has been hampered by the need for cooperation with Nepal.

Most recently, the Deputy Chief Minister of Bihar called for an additional barrage on the Kosi River and proposed similar barrages on other rivers like the Gandak and Bagmati.

The Flood Atlas of Bihar also stresses that better management practices, aimed at minimizing flood risks and damages, may prove more effective than relying on infrastructure.

Conclusion

To mitigate the impact of these floods, a well-balanced strategy that integrates both structural and non-structural approaches for long-term management and protection of vulnerable communities is the need of an hour.

Types of Floods

Coastal Floods: Coastal floods occur when strong winds or storms move towards the coast during high tide.

Flash Floods: Flash floods usually occur in hilly areas in limited space. Here the sudden heavy rainfall or snow thaws are the causes of flooding. The fast-moving torrent of Flash floods can sweep large objects such as cars, rocks and everything that comes in their path.

River Floods: River floods occur due to the inflow of water from heavy rainfall, snowmelt or powerful storms.

Pluvial Floods: Pluvial floods occur in areas that cannot hold rainwater and end up forming puddles and ponds. These types of floods are the event of rural areas.

Urban Floods: When the drainage system of urban areas fails to absorb rainwater, it creates urban floods.

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https://indianexpress.com/article/explained/why-bihar-is-flooded-every-year-9599418/#:~:text=As%20the%20Flood%20Atlas%20of,type%20depression%20locally%20called%20Chaurs.%E2%80%9D

PRACTICE QUESTION Q.Why does Bihar experience annual flooding? Discuss the geographical and economic factors that contribute to the recurrent floods in the region, and measures for effective flood management? (250 Words)