The Aral Sea problem in Central Asia
Хатамов Ж. Б. The Aral Sea problem in Central Asia // Молодой ученый. 2014. №7. С. 190-191. URL https://moluch.ru/archive/66/10908/ (дата обращения: 15.12.2017).
The Aral Sea is situated in Central Asia, between the Southern part of Kazakhstan and Northern Uzbekistan. Up until the third quarter of the 20th century it was the world’s fourth largest saline lake, and contained 10grams of salt per liter. The two rivers that feed it are the Amu Darya and Syr Darya rivers, respectively reaching the Sea through the South and the North. And that is the biggest ecologic problem not only for Uzbekistan but for all Asian countries. And it also impacts on population living around Aral Sea.
Nowadays such an environmental and ecological problems exist in other areas such as Black Sea, Azov Sea, Caribbean Sea, Northern Sea seashores and Aral Sea, Ladoga, Onega, Chad, Great Lakes.
The environmental and ecological problem which occurred in Central Asian and Uzbekistan is Aral Sea. During 1911–1960 years Aral Seas was flown into about 52 km3 in every year. And its salinity level was 9.5–10 percent, water level was 52 metres, depth of water was 16 meters. The water level in the Aral Sea started drastically decreasing from the 1960s onward. In normal conditions, the Aral Sea gets approximately one fifth of its water supply through rainfall, while the rest is delivered to it by the Amu Darya and Syr Darya rivers. Evaporation causes the water level to decrease by the same amount that flows into the Sea, making it sustainable as long as inflow is equal to evaporation on average. Therefore the diversion of rivers is at the origin of the imbalance that caused the sea to slowly desiccate over the last 4 decades. And since building new canals and big dams amount of water flown into Aral Sea by Amudarya and Syrdarya caused water decreasing. Level of salinity rose from approximately 10g/l to often more than 100g/l in the remaining Southern Aral. Salinity of the rivers varies with place and time, as well as through the seasons. When going through the desert, rivers often collect some salt compounds residues in the ground that result in higher salinity, but may well be lowered again after going through irrigated lands. Dams also affect salinity, notably by reducing its variability with the seasons. Smaller lakes within the Aral Sea that have stopped being fed by river flows tend to have higher salinity due to evaporation, causing some or all fishes that either survived or had been reintroduced in the 1990s to die. Even re-watering those lakes does not compensate for the increased salinity over the years. In 1998, water level was down by 20m, with a total volume of 210 km3 compared to 1,060km3 in 1960. Area is getting small year by year.
Nowadays 2 main tasks are being adjusted by Government of Uzbekistan. And it means there are 2 solutions for the country: first is to keep the amount of water and second is to improve ecological environment around Aral Sea.
To keep the amount of the Sea with water level 33 meters the Sea must be flown 20 km3 water by Amudarya and Syrdarya in every year.
The main way of improving ecological environment consists of providing population who live around the Sea with clear water, sending water to dried lakes, areas regularly, fortifying soil with plants and widening grassland, increasing meliorated case of the area.
But in the past time The Aral Sea was considered as one of the main inside seas and was used for fishing, transportation and for other needs. In ancient time water level contained 1.5–2.10, was up to natural features of climate, and amount of water was 100–150 km3, water level area was 400 km3. In dry years amount of water flown into Amudarya and Syrdarya deltas decreased. So, at present time water level of the Sea lowered 16.8 m comparing with 1961.
The desiccation of the Aral Sea greatly increased the number of dust and salt storms in the area. Satellite images have revealed that there are up to ten major dust storms occurring annually in the region, most of them occurring between the months of April and July (Glantz 1999). While before, the pressure from the water surface dampened the strength of the northerly and north-easterly winds, the loss of the sea meant that it's protective action from the wind was significantly reduced. The receding sea left behind large amount of salt, and ground water evaporation further increased the amount of salt from the exposed sea bed. The strong north-easterly winds now pick up the sand, salt, and dust, creating strong dust storms. The salt content in the dust made up about 30– 40 % of the volume in the summer, and was as high as 90 % in the winter (Hydro meteorological Center of Uzbekistan). The storms are often between 150 and 300 km wide. The dust was distributed in areas far beyond the region — the dust from the Aral Sea region was found as far as 500km away from the original source (Micklin 2007). Some of the salt reached the intensively irrigated and cultivated soils, which even ruined the soil far away from the Aral Sea region. It was estimated that the average amount of salt removed from the entire dried seabed was about 43 million metric tons between 1960 and 1984 (Glantz 1999).
The situation in South Island is much worse than other sides. And area of this island includes Red and Black Sands and Amu darya. Drying position of Island hasn’t been observed in the world experiences yet. That is why there is some difficulty to mark this case for the world as well. Because of salinity of ground farm products downed 30 % in Uzbekistan, 33 % in Kazakhstan, 20 % in Kyrgyz republic.
Prior to 1960 the Aral Sea's biodiversity was considered low. It supported no more than 24 species of fish, over 200 species of free-living macroinvertibrates, and 180 land animal species. With the lowering of water and the rise of salinity and toxicity none of the fish species survived. Less than 30 macroinvertibrate species survived and of the land animals that were reliant of the Aral Sea a few dozen remain. There are additional factors that have affected the diminishing native species of the Aral Sea region. With the receding shores once water locked breeding grounds of many fish species became vulnerable to land preditors. Also, with the decreasing volume of animal life in the region more salient species were introduced in an attempt to preserve the 44,000 tonne of fish per annum that the commercial fisheries of the region had procured prior to the 1960's. The newly introduced fish proved brutal competitors for the already vulnerable native species. Nowadays, even other animals not only fishes in this territory are getting few. Nearly there is not an alive creature in this area. These all impact on population health as well. This caused some diseases. By learning demographic growth of population we can get a lot of differences comparing today with the past in this area. Changes in population are important to understand the Aral Sea crisis for various reasons that we will explore. Between 1950 and 1988, the population of the Aral Sea basin grew dramatically — from 13.8 to 33.2 million people, comprising increases from 8.1 to 19.9 million in Uzbekistan, 1.0 to 2.2 million in Kirghizstan, 2.0 to 5.1 million in Tadzhikistan, 1.5 to 3.5 million in Turkmenistan, and 1.2 to 2.4 million in Kazakhstan (all within the sea-basin limits). In 1990, the population of the Aral Sea basin numbered 34 million. Mean annual rates of population increase in the late 1980s amounted to 2.85 % in Uzbekistan, 2.60 % in Kirghizstan, 3.2 % in Tadzhikistan, 2.65 % in Turkmenistan, and 1.06 % in southern Kazakhstan. Today, after two decades of intense demographic growth, the situation has clearly changed, for we see that the mean of the population growth rate in the Aral Basin has diminished.
Today the Aral Sea is one of the main problem in in Asia. Thus a lot of ideas were given for saving the Aral Sea. Some scientists admit that it is impossible to save the Sea and whole sea will be dried afterwards. But others admit that it is possible to save it. And 70 km3 water is needed for saving the Sea.
To sum up, drying of the Aral Sea is very big problem, and that’s to say it became national trouble for Uzbekistan. This problem began existing long years ago. And it is still on. Today it became one of the huge ecological trouble. About 35 million people who live around the sea are under influence of this problem. Nowadays many scientists have been working on experiments for solving this problem.
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