Dam or Lethal Water Bomb

-

 Our school geography book was describing the multi utility of dams like(1) Irrigation (2)Hydro-electricity(3)Flood control (4)Navigation(5) Fisheries(6)Recreation(7)Drinking Water supply or water supply to industry etc.At that time on an average 3 large dams were built every day around the world.As per Er D.K.Mishra in independent India, approximately 35,199 km of embankments have been built around rivers & 4728 nos large dams.Temples of modern India was a term coined by India's first Prime Minister Jawahar Lal Nehru while starting the construction of the Bhakra Nangal Dam & inaugurating the Hirakud dam.But today all over world people are discussing the multi disadvantages of dam or an embankment.During 20th centuries dams were built around the world.Now after completion of 50 years of life period,dams are being razed in different countries allowing the river to have a free flow in its natural path.Disadvantages of dams

1)It killed the fisheries & livelihood of fishermen.The fish ladder built on dams did not help fish to migrate or move ahead.As a result people fond of Hilsa fish in Allahabad,Banaras,Delhi even Hardwar deprived of the taste of this migratory fish after construction of Farakka barrage across Ganga.Americans were deprived of Salmon fish after construction of big dams across the rivers (2)A very large cultivable area, forest,pasture,homeland were waterlogged / submerged due to construction of dams (3)The large displacement of people from their homeland & their rehabilitation due to dam have never satisfied the displaced people & they have turned to revoluntaries(4)It was found instead of controlling flood,dams promoted flood & nos of flood have increased after construction of dams.The flood affected area of India has increased from 25 million ha in 1952 to 49 million ha in 2011(5)The pressure of huge quantity of water in the reservoir of a dam enhances seismic activity & one of the reasons of dam failure is induced  earth quake.Though China has denied that the devastating 2008 Sichuan earthquake was caused by the Three Gorges project, the 410-mile long reservoir of the dam means more chances of earthquakes and landslides due to the huge weight of the water it holds and its varying levels in different weather conditions that puts pressure on.Similarly for the 126 year old  Mullaperiyar dam in Kerala, IIT-Roorkee estimated in its report that it would fail if an earthquake of 6.5 magnitude occurs in a radius of 16 km when the water level in the dam is at 41 meters. According to the UN study, such an event would endanger the lives of 3.5 million people in Kerala.(6)The dams trap river silt or sediment at the rate of 0.5 to 1% of the dam's storage capacity every year.By restraining sediment upstream, it accelerates erosion down stream.Silt deposit in cultivable land stopped for ever.Due to sediment deposit in dam, the water holding capacity of dam is reduced every year.The river bed is raised promoting flood,new land mass or island is developed in river bed upstream of the dam. This phenomenon has been observed in river Ganga in Bihar after construction of Farakka dam.Almost 300 million tons of silt is now deposited annually at Farakka barrage.This has elevated the river bed by almost 20 feet & even made opening the gates a difficult task & flood in Bihar every year is due to Farakka dam. Sri Nitis Kumar,Chief Minister,Bihar has already proposed Central Government for removal / decommissioning of Farakka dam(7)Dam evaporates more water than they store in dry seasons.Evaporation annually consumes between 5 to 15% of Earth's stored fresh water.An additional 364 billion cubic meter of water is lost every year because of evaporation from these massive water storage sites. (8)Dam is a polluter. It warms the water & reduce absorbed oxygen in water due to heat.It kills aquatic creature that survive on absorbed oxygen in water but blooms  algae.The large dams contribute more than 4% warming effect.As per Brazil's National Institute for Space Research,52000 large dams(50 feet or higher) of the world reservoirs contribute 25% of human  caused methane, the world's largest single source.Earth's millions of smaller dams compound that effect(9)After completion of 50 years or life period, these dams are like lethal water bombs & may breach at any time destroying cities,towns,villages & killing large population.

Dam breach in India-

On 31st March,2017 in Malsisar village, Jhunjhun district of Rajasthan a dam was breached within a period of 3 months in which 588 crore was spent .Between 2000 to 2009 around 200 nos dam breaching cases have taken place around the world.On 25th August,1894, Gohana dam was breached in Godwal area of India.On 19th August,1917, Tigara dam of Gwalior was breached.On 7th December,1961 Punseth dam of Pune was breached.Kharagpur dam of Bihar was breached on 1961.Machu dam of Gujarat was breached in 1979 killing 200 people.Bhagalpur dam of Bihar was breached in 2017.Tiwar dam of Ratnagiri of Maharashtra was breached in 2019.In Henan area of China, Benkiaao dam was breached in 1975 killing around 1 lakh 75 thousand people & 10 lakh people were displaced.In 2006,the Kaloko dam in Howaiian Island of kauai collapsed,unleashing 70 feet high,1.6 million ton fresh water tsunami that carried trees,cars,houses & people out to sea drowning seven people.There are more than 2.5 million dams in USA.There are an estimated 8 lakh dams worldwide.By 2020, 85% dams of USA have crossed life period of 50 years.Therefore roughly 900 dams have been removed in USA between 1990 & 2015 with a target of 50 to 60 every year.A recorded 1,957 dams have been removed in the U.S. since 1912.In 1998,US administration removed 12 dams,in 2005 it terminated around 56 dams,in 2018 it removed 99 dams, in 2020 it removed around 69 dams.Fifty-nine dams were removed in 2021, reconnecting more than 2,290 miles of rivers.Fifty-seven dams were removed in 2021 that freed 2,131 milesCanada,France,Japan have already started the work of dam removal. 



Comments

Post a Comment

Popular posts from this blog

Southern Region Farm Machinery Training and Testing Institute (SRFMTTI),AP.

-
Image
 Southern Region Farm Machinery Training and Testing Institute (SRFMT&TI) is located in Garladinne, Anantapur. The Institute conducts training courses in operation, maintenance and repair of farm machinery and equipment, and in the improved mechanized farming techniques for the benefits of farmers, tractor owners, technicians, in-service personnel. It also conducts energy conservation and management camps and arrange training for the women working in the field agriculture.  The Government of India  established  this prestigious Institute at Garladinne in Anantapur Dist (A.P.) in the year 1983 for promotion and strengthening of Agricultural mechanization through Training and Testing programmes in the southern region.
Read more

Agrl Engineering  in India, Allahabad.

-
Image
  Sam Higginbottom University of Agriculture, Technology and Sciences  ( SHUATS ), formerly  Allahabad Agricultural Institute , is a state agricultural university in  Allahabad, Uttar Pradesh , India.It operates as an autonomous Christian minority institution under the 'Sam Higginbottom Educational and Charitable Society, Allahabad'.It was established in 1910. Mason Vaugh  (June 27, 1894 – October 7, 1978) was an American agriculturalist who developed the first agricultural engineering department outside  North America  in 1921 at  Allahabad Agricultural Institute .He also served in the  US Army  during  World War I . Alma mater- University of Missouri Scientific career- Fields Agricultural Engineering , Agricultural machinery Institutions- 1) Allahabad Agricultural Institute 2) University of Missouri The Ohio State University Prof. MasonVaugh  is the father of Agricultural Engineering in India. He was an agricultural engi...
Read more

Water Management

-
Image
 The meaning of water management is optimization of watering a crop as per it's requirement.In coming years we are going to face water stress in many parts of the world where as  to feed the growing population, cultivable land needs to be  increased along with water requirement for Agriculture. Therefore we are to control water while irrigating a crop. We should not allow water for deep percolation and drainage rather supply water up to root zone depth of a crop. We are to harvest each drop of rain water & prohibit it to drain to river & ocean. For example Rice consumes about 4,000 - 5,000 litres of water per kg of grain produced & It takes about  1500 litres  of water to produce 1 kilogram of wheat. Rice is not a aquatic crop: it has great ability to tolerate submergence. By keeping two  inch standing  water in Rice field, we control weeds but cut off sunlight and aeration to the ground. An innovative method called the System of Rice ...
Read more