Aral Sea - Реферат
Since the very beginning of its existence, the human being has been developing. It has never stopped, and it never will. During the last couple of centuries it has been developing very aggressively, and it has reached tremendous achievements in all fields. Unfortunately mankind has achieved tremendous success in polluting its environment also. Nowadays, nature is missing many of its inhabitants: – those who are supposed to be under the protection of humans as young brothers and sisters. Pollution was the reason for their extinction. Finally, the humanity started paying more attention to what surrounds it. It started thinking about the future, its future generations, and the inheritance to these generations. People have started asking themselves more often questions like, “What will we have left to other children after us?” Currently, humanity has plenty of global environmental problems that it has to take care of now. Tomorrow will be too late. Some of these global environmental problems are global warming, deforestation, freshwater contamination, destruction of ozone layer of the earth, pollution of space orbit of the earth by parts of used equipment. Desiccation of the Aral Sea is one of the items on the list.
The Aral Sea, which is also considered to be a lake or Inland Sea in Central Asia, is located in southwestern Kazakstan and northwestern Uzbekistan, near the Caspian Sea. The Aral has no outlet. The Aral Sea is still listed as the fourth largest lake in the world. But it has been shrinking for decades, and the statistics might change. In time the Aral Sea may not the fourth largest lake in the world anymore.
Nowadays, two major problems have risen before the governments of Uzbekistan and Kazakstan; the desiccation and as a result of this threat of the complete disappearance of the sea, and the danger of the broad extension of anthrax bacteria that was stored by the Soviet Army Vozrozdenia Island.
In comparison with the size of the sea in the 1960’s, the Sea has declined in size by seventy-six percent. The initial reason for the Aral’s decline is the fact that Soviet planners diverted water from Aral’s two big feeding rivers (Amu Darya and Syr Darya) into cotton fields in the territory of Uzbekistan. Because of this irrigation, the sea is now seventy miles away from its former bank (in some places even more). Ninety percent of the Syr Daya’s water is diverted into canals and reservoirs. Millions of people in Central Asia rely on the rivers for a livelihood. Uzbekistan, for instance, generates twenty-eight percent of its hard currency from cotton irrigated with river water (The Aral Sea, http:///visearth.ucsd.edu/VisE_Int/aralsea/).
Planning the irrigation system, the Soviet planners were only after high rates of cotton harvests. Unwise use of water has led to the current state of the Aral Sea. The salt content of the Sea’s waters increased by about threefold, adversely affecting plant and animal life and causing the fishing industry to decline.
The disappearance of the sea as a part of the ecosystem is just one problem that is followed by hundreds of subsequent problems. One of them has already risen: The drying of the sea has left behind three million hectares of desiccated seabed, covered with accumulated salts which the wind carries away and deposits over thousands of square kilometers of arable land turning the land into dead ones. One can see white ridges amid the soil in the field. Salty dust from the dried out land blows in squalls through the area, causing discomfort and respiratory problems. Wind brings more than a hundred tons of salty dust per square mile on the region every year. As a result of this, trees do not bear fruit any more.
The Aral Sea’s desiccation has an influence on everything that is around it. The climate in the region has changed significantly; the winters are even colder, summers are even hotter.
The sea was not only the water supply for the population, but it was the source of their income. A large part of the population was involved in fishing and resort industries. Now, that the Sea is far away, these businesses are no longer available, and that leads to deterioration of the financial situation of the people in the area.
“In city of Muynak, the three hundred-vessel fleet once employed a thousand fishermen. It is now a collection of rusting hulls half-buried amid the dunes on the edge of town. Yet the sixty-year-old canning factory still clatters, all steam and stench, although its seven hundred workers handle fish brought by lorry from the lakes around Tashkent, one thousand miles away” (Reeves, The Sea Sickness).
The sea has turned from a rich fishing ground to a prairie of poison dust. Desiccation has a great deal of influence on the population’s health; the change in environment has significantly increased rates of birth defects, infant mortality, cancers, malnutrition, respiratory diseases, and the anemia suffered by almost all women of child-bearing age. Malnutrition has risen sharply; fish is no longer a part of the people’s daily diet. Another side effect imposed on the population is a dramatically increased rate of tuberculosis in the area.
One of the causes of health deterioration is that over three decades the water could not or barely could make it to the Aral Sea. The Aral’s water contains a lot of pesticides. The pesticides sank to the bottom of the lake. As the lake dried up, this layer of pesticide became exposed to the wind, which blows it away on the other lands.
The partial solution for the problem is to build a dam to keep water from flowing into the larger, southern portion. Plans call for the structure’s base to be 150 yards wide. If money is found for the construction, the water level of the northern sea will rise to the same level it was in 1960’s. As a result of the construction, salination of the sea will decrease. This fact might contribute to restoration of fishing and resort industries.
For the population of this region, the dam is a rare ray of hope. If the dam holds on the small sea, a microclimate will be restored there. The health of people will improve and it will be good for the economy.
Calculations by the Kazak Academy of Science in Almaty, the country’s main commercial city, suggest the entire sea might disappear by 2010 without the dam. Currently the northern Sea is one-sixth as large as the southern portion. If the surface area is reduced, less water will evaporate. The full damage caused cannot be repaired, but it can be stopped from going any further.
The second threat to the Aral Sea and its inhabitants is anthrax bacteria stored 1988 by the Soviet Army. The Army was trying to get rid of its germ weapons and stored the bacteria on one of the Aral’s islands. Soldiers dug large pits and poured a mixture of anthrax bacteria and bleach. The bleach was supposed to kill the bacteria, but it did not. Even with the passage of time, the bacteria stay alive.
Now, the Sea is drying out and this island can become a part of land. This fact carries the threat that anthrax bacteria can be exposed to atmosphere one day, and it will become a very serious danger to both countries.
At this time, both governments in cooperation with the United States are undertaking actions in order to prevent the extension of the bacteria.
Over the two last centuries many of Earth’s inhabitants became extinct as a result of environmental pollution. It is time to stop it; otherwise the next extinct inhabitant might turn out to be humanity itself.
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