What is a flood?
When water inundates land that is normally dry, this is called a flood. Floods are a natural process and are the most common of all natural disasters. A flood is an overflow of water that submerges land. One of the highly flood prone countries in the world is India.
It is not possible to control the flood disaster totally, but by adopting suitable measures the flood damages can be minimised. Some floods develop slowly, while others such as flash floods can develop in just a few minutes and without visible signs of rain.
Approximately 60% of the flood damage in the country occurs from river floods, while 40% is due to heavy rainfall and cyclones.
Damages by the Himalayan Rivers account for 60% of the total damage in the country. In India, Bihar and Assam have been the worst hit due to frequently occurring floods.
West Bengal, Orissa, Andhra Pradesh, Kerala, Assam, Bihar, Gujarat, Uttar Pradesh, Haryana and Punjab are the states comes under the category of "India Flood Prone Areas".
About 27% of the flood damage in the country is accounted for by Bihar, 33% by Uttar Pradesh.
Types of Flood:
Areal flooding: These type of floods occur in flat areas like floodplains and in local depressions because the velocity of overland flow depends on the surface slope.
Riverine (Channel): This type of flooding refers to floods occur in river and stream channels, from the smallest ephemeral streams.
Estuarine and coastal floods: refers to the flooding in estuaries and is commonly caused by a combination of sea tidal surges caused by winds and low barometric pressure.
Flooding in Coastal areas may be due to the storm events at sea, resulting in waves over-topping defences or in severe cases by tsunami or tropical cyclones.
Urban floods: They can be defined as the inundation of land or property in more densely populated areas, caused by rainfall, storm sewers.
Catastrophic floods: They are usually associated with major infrastructure failures such as the collapse of a dam, landslide, earthquake or volcanic eruption.
Effects of floods:
There are various effects of floods as follows:
Loss of life.
Damage to buildings and other structures, including bridges, roadways, and canals.
Damage power transmission and sometimes power generation.
Causes of floods
Urban Drainage Basins.
Silting in Delta areas: deteriorates the discharging capacity of rivers which causes a flood in that region.
Channels with Steep Sides
Obstruction of free-flow of rivers: by Roads,embankments, railway lines, canals etc.
Storm Surges and Tsunamis.
A Lack of Vegetation.
Rise in river bed
Melting Snow and Ice
Earthquake and Landslide
Disastrous floods in past:
Floods in Kosi River
Assam Floods, 1998
Maharashtra Floods, 2005
Ladakh Floods, 2010
Assam Floods, 2012
Jammu & Kashmir Floods, 2014
Uttarakhand Floods, 2013
South Indian Floods, 2015
Assam Floods ,2015
Flood management measures mainly deal with mitigation rather than total elimination. An efficient flood management /water management and requires a most holistic approach. Our failure to develop and manage our water resources causes frequent occurrence of floods and drought.
There are various authorities /departments at central and state level that involve in flood management.
Drainage and Embankments are mentioned in State list. Thus, the primary responsibility to deal with floods is of states.The role of central government is technical and advisory in nature.
At the central level:
NDMA(National disaster management authority) deals with all types of disasters including the floods.
The National Executive Committee (NEC) having administrative control.
Central water commission issues flood forcasting,
Indian metreological department,National centre for medium range forcasting,Central Flood Control board,National Disaster Response Force are some of the important authorities at central level.
At state level:
State Disaster Management Authorities (SDMAs) and State Executive Committees (SECs) to perform similar functions at the state level.Irrigation department and public works departments are some of the important authorities at state level.
Initiatives in order to deal with floods:
Policy Statement 1954: Different methods of flood protection structural as well as non-structural have been adopted under National Flood Management Programme in 1954. Structural measures include drainage channels, anti-erosion works, channel improvement works, storage reservoirs, flood embankments, detention basins etc. and non-structural measures include flood forecasting, disaster preparedness etc.
High-Level Committee on Floods (1957).
Policy Statement of 1958
National Flood Commission (Rashtriya Barh Ayog) 1980:It was set up by government of India to evolve a coordinated, integrated and scientific approach to the flood control problems in the country.
Regional task forces 1996:It was set up to review the impact of the recommendations of the RBA and to suggest short term and long term measures.
National Water Policy (1987/2002/2012): The National Water Policy (1987) recommended that sufficient flood cushion should be provided in water storage projects to facilitate better flood management.
Flood Management and Border Areas Programme (FMBAP)” for Flood Management Works in entire country and River Management Activities for the period 2017-18 to 2019-20 .It has been framed by merging two schemes titled “Flood Management Programme (FMP)” and “River Management Activities and Works related to Border Areas (RMBA)”. This scheme will benefit towns, villages, industrial establishments from floods and erosion in the country.
Google, as part of its AI for Social Good initiative, is working with Indian government to predict flood around Ganga and Brahmaputra.
Things to be done to mitigate floods:
Flood forecasting and warning and Decision Support System (DSS) should be established.
Set up a National Flood Management Institute (NFMI).
Set up a central organisation to lay down policy and implement Flood Management measures.
Implement some basic remedies to mitigate the flood situation by involving local communities. The Panchayati Raj institutions and Urban local bodies have been recognised as important stakeholders at all stages of a disaster in the National Disaster management plan.
Some degree of protection against floods can be achieved by having storage dams across major rivers and regulate the flows downstream into a river, efficient management of flood plains, flood plains, floodproofing including disaster preparedness.
Interlinking should be done to mitigate the flood situation. It was found very useful. The social scientist also approved of it.