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Add to FavoritesWater is our most important commodity. Without water we can't live and societies cannot flourish or in some cases cannot even subsist. The rivers of the world which provide the water for agriculture, mining, drinking, and hydroelectric power are in trouble.
The water tables are declining in many major areas of the world due to global warming, climate change, and the building of dams for irrigation purposes, which results in water evaporation.
There are two types of aquifers that supply water - replenishable and nonreplenishable. The aquifers of India and North China Plain are replenishable, but the Ogalla aquifer in the United States, and the deep aquifers of the North China Plain, and the aquifers of Saudi Arabia are nonreplenishable. The drying of rivers in these areas means the end of agriculture in the southwestern US and the Middle East.
The hardest hit areas where rivers are already drying up are
* The United States, where the water table has dropped by 100 feet (30 meters) in Southwest US and where thousands of wells have gone dry in the Southern Great Plains.
* Gujarat, India, where the water table is falling by 20ft/year. 95% of the wells owned by small farmers have dried up.
* Pakistan, Iran, Saudi Arabia, Yemen, Israel, and Mexico are experiencing severe water shortages caused by the overpumping of aquifers.
* The Colorado River in Southwest United States, the Yellow River in North China, the Nile in Egypt, the Indus in Pakistan, the Ganges in India are all experiencing depletions in river volume and flow. Smaller rivers have disappeared.
The Colorado River rarely makes it to the sea and is usually drained dry be the time it reaches the Gulf of California. The Yellow River ran dry in 1972 and since 1985 does not reach the sea. The Nile rarely reaches the sea. The Tigris and Euphrates rivers are also in trouble.
Many of the smaller rivers or tributaries of the great rivers the world over have already dried up.
Africa will probably be the hardest hit by global warming which will cause less rain to fall in Africa within the next 50 years. A small decrease in rainfall can cause a substantial decrease in available river water. The prediction is a 10 to 20% reduction in rainfall by 2070. [1]
Today the copper and gold mines in Chile and Peru are pumping water in from the Pacific Ocean to lessen the stress on streams and waterways within the farming districts of these areas. But how much water can be pumped from the oceans?
So will our great rivers die? It all depends on how the people of the world relate to this problem of global warming and climate change and how they go about trying to conserve water, the ecosystems, and the environment. It might also depend on evolutionary forces.
According to research scientists at the Met Office Hadley Centre, the University of Exeter, and the Centre for Ecology and Hydrology, the increase of carbon dioxide levels will cause plants to use less water, which will allow more water for rivers causing "river flow increases." [2]
So will some rivers dry up and new rivers form? Or will all rivers dry up? Without human intervention into the detrimental causes of environmental pollution, global warming, and climate change, the rivers will continually dry up. However without any intervention whatsoever, the rivers will dry up, and new rivers may form.
Didn't the great Mississippi River form millions of years ago through the melting of glacial ice caps? So isn't it possible that the glacial ice caps melting in the Himalayan Mountains could foster new rivers forming in China?
However we are reading that the glacial ice caps melting in China due to global warming are causing rivers to dry up. But the Himalayan glaciers are melting at an "unprecedented rate" and the rivers are drying up due to temperature rising and "over-exploitation" of water systems. [3]
So will our great rivers die? Our Great Rivers are the Mississippi, the Thames, the Amazon, the Zambezi, the Yangtze, and the Volga. They are still intact and sometimes overflowing. New waterways are continually formed due to changes in rainfall and temperatures. These will empty into the great rivers.
But still man must make every endeavor to not overuse our natural resources and find more efficient methods for power and irrigation. Dams and hydroelectric power are helping to kill our rivers.
We need our Great Rivers for the survival of the human race and the animal kingdom.
References:
[1] http://news.national geographic.com/news/ 2006/03/0303_060303_ africa_2.html
[2] www.sciencedaily.com /releases/2007/09/07 0905083617.htm
[3] www.commondreams.org /archive/2007/06/20/ 1993/
Learn more about this author, Colette Georgii.
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No
The global warming of the Earth climate is already causing heavy effects and one of them is surely particularly harmful for local populations; the temperate, tropical and equatorial regions are becoming drier and drier. This means less rains and moisture in the basin of the longest rivers of the world, like Nile, Niger, Hindus, Tigris and the Euphrates Rivers and even the equatorial Congo and Amazonas Rivers.
This will not cause the death of these rivers because "death" means a river becomes permanently dry for the whole year or nearly and also its sources become dry, as it happened in deserts. The great rivers, instead, will reduce their average water flow even drastically during the year, with total dryness during the hottest and driest periods and violent floods, during short periods. These rivers will not die, but will become ill, more or less seriously.
This is not a great relief, in any case; this situation will be enough to cause a lot of dramatic problems in the regions included within the basin of these rivers, with changes that will be very hard to face, just because occurring within few years.
Last year, just the Amazon River, in South America, knew a never seen dryness that reduced the longest river of the world after the Nile (its banks were distant up to 1-2 km) to a stream few tens of metres wide, in some points.
Manaus, the largest town of the Amazon region, in Brazil, was totally insulated because boats and ships couldn't move anymore and were all aground. Many aquatic animals, used to water abundance, died and caused great environmental problems.
In the temperate regions, the increased variability of water flows during the year is enhanced by the reduction of rains and snow falls and also by the withdrawal or disappearing of glaciers in the mountains where rivers have their sources like in the Alps, Rocky Mountains, Andes, Himalaya, Caucasus, Atlantes. Glaciers, to be defined so, must be present all the year (although with a seasonal and cyclic minimum in summer) and can guarantee a relative constancy in rivers flow during the year. also in the hottest season.
If the glaciers of the main mountain ranges of the world will keep on reducing so quickly, until disappearing, the most important rivers of Central Europe, Asia and America, like the Rhine, the Rhone, the Po, the Danube, the Mississippi, the Colorado and the main Chinese and Indian rivers will not die, but they will change their nature becoming highly seasonal, fed only by rains, when these will have the kindness to fall. The rivers I quoted are only some of the most important, but all the others have a very important role in the life and economy of all local peoples of the world.
Today, in Europe, along the northern Mediterranean coasts, rains are rare and inconstant for the whole year, even in autumn and in winter, when many weeks can pass without a single rain drop on wide areas, as I can personally witness for my region that is Liguria, Italy.
The Ligurian Riviera was defined by foreign travellers of the XIX century "a natural paradise" for its mild climate and abundance and variety of vegetation. Today, instead, the long and irregular dry periods ease the wood fires that leave the soil even drier and exposed to a fast erosion. Liguria, in fact, is all made by mountains along the sea, with high slopes; its rivers directed to the sea are simple streams, nearly all not longer than 20-30 Km and strongly depending on rains and on the presence of wet woods on the mountains.
In all the world, agriculture will have more and more frequently hard times in the rich and in the poor Countries, with the block of the irrigation systems that drain water from rivers, channels (derived from natural rivers and sources) and from their tributaries, when these are dry for many weeks or months.
Also ground-waters will not provide anymore the cultivations with the needed water because just rains from the sky and rivers from the bottom of their beds feed them. So, many traditional cultures (rice, maize, fruit trees, vegetables,...) will be necessarily replaced by others, less water-demanding, if this will be possible and economically convenient. The water scarcity in the planes of these "sick" rivers will oblige local authorities to look for water sources from the mountains tens or hundreds of Km farther, with additional costs and a further stress on these mountain sources, where glaciers keep on withdrawing themselves.
Rivers' dryness will produce another serious consequence, already observed, although temporarily: in the delta and mouth zones of rivers, the sweet coastal ground-waters will withdraw upstream, (not being fed anymore by a sufficient flow from the main rivers) for the advance of the salty sea water at their place. This excess of salt will "burn" and make sterile the soil, making impossible agriculture and causing the death of the coastal natural vegetation, in a chain of environmental and economic damages.
The great rivers will not die for the global warming, but their reduction will cause death and desolation around their course, changing also the landscape, in the long run. An equatorial forest will not survive as such if its usual very wet and hot climate would become equally hot but dry. Its typical vegetation and fauna will be largely killed by the lack of water and by fires, more and more frequent, without the time to adapt to this new situation. The areas undergoing this deforestation will become desert and sterile and the equatorial forests risk to become a savannah or an open dry forest in the next decades (like in Africa), or even desert, if somebody, pushed by the need or by greed, will try to profit of forests reduction to practice further agriculture or breeding activities.
To conclude, we can affirm the climate alone can do much to reduce rivers flows, but human irresponsibility and excessive impact on the territory is surely worsening this situation, making the land weaker and more vulnerable to the relatively fast warming we are experiencing today, mainly, with deforestation and intensive farming and breeding.
Learn more about this author, Aldo Bonincontro.
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