- By Bone Tint Hlaing
From the beginning of human existence, the most essential needs of human beings are regarded as food, clothing and shelter. At the time, there were no stores to buy food, shelter and clothing; people had to cooperate in small groups to make clothing and shelter. The earth’s climate was very different and the world was a much colder place to live on than our modern world. Wild herds of animals roamed the land in search of food, which was scarce at that time. In order for Stone Age people to survive, they had to move with these herds of animals. Many of the world’s inventions and discoveries were made gradually thanks to these basic necessities of mankind. Many inventions have greatly changed human’s life and they can fulfill many basic human needs and improve the living standards of humankind.
Among these inventions, electricity is presumably one of the most important blessings that science has given to mankind and it has also become a part of modern life and one cannot think of a world without it. Electricity has many uses in our day to day life.
Due to growing populations and modern technologies, many countries including Myanmar have built many dams and irrigation canals which can store water for later release for such purposes as irrigation, domestic and industrial use, and power generation. Dams provide a wide range of economic, environmental and social benefits to the country.
Reducing the Impact of Drought
Many countries including Myanmar suffer climate change, issues of loss and damage due to global warming which can cause enormous environmental, social and economic consequences. Myanmar faces more extreme weather events as temperatures rise: cyclones, storms, floods and droughts, fire hazards, earthquake, tsunami and landslides.
As for the Ministry for Agriculture, Livestock and Irrigation preventive measures are being made to mitigate the effects of flood and drought in the country. The ministry has performed state management functions in the fields of agriculture, forestry, salt production, fishery, irrigation/water services and rural development nationwide.
Many dams are constructed in the world, mainly for power generation, irrigation/water supply or flood prevention.
The dams have positive as well as negative impacts on the environment: the environmental consequences of large dams are numerous and varied, and includes direct impacts to the biological, chemical and physical properties of rivers and riparian environments.
The dam wall itself blocks fish migrations, which in some cases and with some species completely separate spawning habitats from rearing habitats.
Moreover, it also traps sediments, which are critical for maintaining physical processes and habitats downstream of the dam (include the maintenance of productive deltas, barrier islands, fertile floodplains and coastal wetlands).
Another significant and obvious impact is the transformation and upstream of the dam from a free-flowing river ecosystem to an artificial slack-water reservoir habitat.
Changes in temperature, chemical composition, dissolved oxygen levels and the physical properties of a reservoir are often not suitable to the aquatic plants and animals that evolved with a given river system.
Indeed, reservoirs often host non-native and invasive species (e.g. snails, algae, and predatory fish) that further undermine the river’s natural communities of plants and animals.
The alteration of a river’s flow and sediment transport downstream of a dam often causes the greatest sustained environmental impacts.
Life in and around a river evolves and is conditioned on the timing and quantities of river flow. Disrupted and altered water flows can be as severe as completely de-watering river reaches and the life they contain.
Yet even subtle changes in the quantity and timing of water flows impact aquatic and riparian life, which can unravel the ecological web of a river system.
A dam also holds back sediments that would naturally replenish downstream ecosystems. When a river is deprived of its sediment load, it seeks to recapture it by eroding the downstream river bed and banks which can undermine bridges and other riverbank structures, as well as riverside woodlands.
Riverbeds downstream of dams are typically eroded by several meters within the decade of first closing a dam; the damage can extend for tens or even hundreds of kilometers below a dam.
Large dams have led to the extinction of many fish and other aquatic species, the disappearance of birds in floodplains, huge losses of forest, wetland and farmland, erosion of coastal deltas, and many other immitigable impacts.
Top 10 Deadliest Natural Disasters
A natural disaster is the consequence of a natural hazard (e.g. volcanic eruption, earthquake, and landslide) which moves from potential in to an active phase, and as a result affects human activities. In some cases these disasters have led to the loss of millions of lives.
This is a list consisting of the deadliest floods worldwide:
(1)Yellow River Flood – 1931, China (2)Yellow River Flood – 1887, China (3)Severe earthquake -1556, China (4)Cyclone _ 1970, Bangladesh (5)Cyclone _ 1839, India (6) Antioch Earthquake in the Byzantine Empire in 526 (7) Tangshan earthquake _ 1976, China (8) Haiyuan earthquake _ 1920, China (9)Banqiao Reservoir Dam Flood _ 1975, China (10)The 2004 Indian Ocean earthquake and tsunami.
Benefits of Dams
Dams are designed to last many decades and so can contribute to the generation of electricity for many years. The lake that forms behind the dam can be used for water sports and pleasure activities. Often large dams become tourist attractions in their own right. The lake’s water can be used for irrigation purposes and the buildup of water in the lake means that energy can be stored until needed, when the water is released to produce electricity. When in use, electricity produced by dam systems does not produce greenhouse gases. They do not pollute the atmosphere.
Dams provide a range of economic, environmental, and social benefits, including recreation, flood control, water supply, hydroelectric power, waste management, river navigation, and wildlife habitat and it can provide prime recreational facilities such as boating, skiing, camping, picnic areas, and boat launch facilities.
In addition to helping farmers, dams help prevent the loss of life and property caused by flooding. Flood control dams impound floodwaters and then either release them under control to the river below the dam or store or divert the water for other uses. For centuries, people have built dams to help control devastating floods.
Translated by Win Ko Ko Aung