Environmental Effects of Hydro-Power

Environmental concerns over massive dams have risen over the years. Although hydro-electric power is generally seen as an environmentally clean source of power as it does not release harmful emissions of greenhouse gasses as in the burning of fossil fuels in thermal plants notwithstanding its impact on natural water channels is quite considerable.

"Akosombo Dam is spilling water, Ghana" by ZSM - Own work. Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Akosombo_Dam_is_spilling_water,_Ghana.JPG#mediaviewer/File:Akosombo_Dam_is_spilling_water,_Ghana.JPG

“Akosombo Dam is spilling water, Ghana” by ZSM. Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons

The construction of dams has affected over 77 percent of the annual discharge of the large rivers in the northern third of the world. Many studies show that there are approximately 36,000 dams over 15 metres (45 feet) high that, when full, contain about 20 percent of the annual runoff (rainfall not absorbed by soil) for the globe. While offering some benefit to humans, these dams have reduced the ability of rivers to transport water and sediment to the ocean. This change affects the ecology of rivers as well as the biology of the oceans receiving the river water.

Some of the oldest dams have stopped functioning because their reservoirs have filled with huge amounts of sediment. Dams also block the passage of fish and other aquatic animals upstream to spawning grounds.

Dams alter the water temperatures and microhabitats downstream. Water released from behind dams usually comes from close to the bottom of the reservoirs, where little sunlight penetrates. This frigid water significantly lowers the temperatures of sun-warmed shallows downstream, rendering them unfit for certain kinds of fish and other wildlife. Natural rivers surge and meander, creating small pools and sandbars that provide a place for young fish, insects, and other river-dwelling organisms to flourish. But dams alter the river flow, eliminating these microhabitats and, in some cases, their inhabitants.

Finally, dams also prevent nutrient-laden silt from flowing downstream and into river valleys. Water in a fast-moving river carries tiny particles of soil and organic material. When the water reaches a pool or a flat section of a river course, it slows down. As it slows, the organic matter it carries drops to the river bottom or accumulates along the banks. Following heavy rains or snowmelt, rivers spill over their banks and deposit organic matter on their floodplains, creating rich, fertile soil. Some of the organic matter makes it all the way to river mouths, where it settles into the rich mud of estuaries, ecosystems that nourish up to one-half of the living matter in the world’s oceans. Large dams artificially slow water to a near standstill, causing the organic matter to settle to the bottom of the reservoir. In such cases, downstream regions are deprived of nutrient-laden silt.

 -          Ola Olaniyan

ABOUT THE AUTHOR

Ola Olaniyan is an architect and currently a postgraduate student of the Department of Urban and Regional Planning at the University of Ibadan, Nigeria. A dedicated conservationist and environmentalist, he is one of the pioneers of Green Hope Africa an initiative for Physical/Biodiversity Conservation in Africa. He earned his Bachelor of Science in Architecture as well as Master of Architecture from Obafemi Awolowo University, Ile-Ife, Nigeria.

Be Sociable, Share!

    Pollution in Pictures from Olonde Omondi

    Olonde Omondi offers 4 more images with a hard-hitting environmental theme. Olonde Omondi has a Diploma in Graphic Design and enjoys expressing himself in a variety of styles all based on realistic interpretation of our world. Major areas of interest include cartoons and caricature, graphic art and illustration as well as painting. Art history and poetry also play substantial roles in his art.

    Creative Commons License
    This work by Olonde Omondi is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
    Permissions beyond the scope of this licence are available from smudgetrial2 AT yahoo.com.

    Be Sociable, Share!

      Olonde Omondi draws recycling

      A holder of a Diploma in Graphic Design, Olonde Omondi enjoys expressing himself in a variety of styles all based on realistic interpretation of our world. Major areas of interest include cartoons and caricature, graphic art and illustration as well as painting. Art history and poetry also play substantial roles in his art.

      Creative Commons License
      This work by Olonde Omondi is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
      Permissions beyond the scope of this licence are available at smudgetrial2 AT yahoo.com.

       

      Be Sociable, Share!

        Vain Deaths

        That a president of a developing country that has to depend on donor funds to meet their yearly budget, personally sets natures resources worth billions ablaze is very ironic. I can even call it sad. A resource that has a readily available market, that caused the death of thousands of our wildlife, should never be wasted that way again.

        President Kibaki sets ivory on fire

        President Kibaki sets ivory on fire

        Does it not matter at all that an elephant, or a rhino was murdered somewhere in cold blood, for one to have mercilessly cut off their tusks with the intention of enriching themselves by selling them in the Asian black market? According to the Sheldrick Wildlife Trust, about 36,500 elephants are killed in Africa alone every year by a set of serial killers we have christened poachers. A little of the ivory acquired by this heinous act is intercepted at the airports, and is ‘confiscated’. Part of it kept as exhibit for the prosecution of the persons found with it. What we see later in our country is a huge stack of ivory worth billions of shillings ceremoniously being burned by the president, in the presence of other very influential learned people of excellent economic and environmental knowledge.

        Billions up in flames

        Billions up in flames

        How I sincerely wish that things were a little different. I wish that once such cargo is intercepted, it is not confiscated but stored. That the offender be not remanded for months on end before prosecution and trial, but to be convicted within shortest time possible. Let it be known that such cases shall not be amongst those that will drag in the courts forever. There should be no freeing poachers or illegal ivory traders on bond, unless under very special circumstances that will require very convincing backup. Punishment for such offenders should not be less than ten years behind bars.

         

        Most important though is the stored ivory. It doesn’t change anything by burning them, does it? Bad cannot be paid by worse if our aim is to see positive progress. By burning, the dead elephants and rhinos from which these tusks were removed will have died in vain. If we really care to reduce, and even stop poaching, it would be of better sense to honor their deaths by protecting their surviving kin. We could go ahead and legally sell the ivory by a process of international bidding and selling them to the buyer attaching highest value to them. The sums acquired from the sale can then be used to improve measures being put to protect wildlife, like research, securing park perimeters, hiring more rangers and equipping them to effectively deal with poachers. This way, there truly will be progress in curbing poaching, and the shame of burning billions when we desperately need them will be no more.

        Burning will not stop poaching, I dare say. There should be no pride in burning ivory.

        Be Sociable, Share!

          Olivia, the 7year Old Zoologist

          Seven year Old Olivia Binfield stands before thousands to send a message with Lucy, her snake coiled around her little neck. She thinks she wants to become a zoologist when she grows up; but she doesn’t have to wait that long; she is one of the best zoologists already, and the best poet too.

          Olivia and her Lucy on the stage

          Watch her as she tells you why she thinks “man’s such a fool.” Olivia asks that you may listen to her “passion, although it may not be in fashion.” She is the voice of all the endangered animal species.

           

           

          Be Sociable, Share!