Asia > Kazakhstan / Uzbekistan

The Aral Sea: One of the Worst Environmental Disasters

lakeAral Sea
countryKazakhstan, Uzbekistan
surface area23,866 km2
maximum depth67 m
average depth1 m
lake typeEndorheic, natural
catchment area622,507 km2
altitude29 m
volume27 km3
inflowsNorth: Syr Darya, South: groundwater only, while previously the Amu Darya
shore length1,888 km
age2 - 20 million years
settlementsAral, Kazakhstan
residence time192 days
originTectonic
average discharge1,620 m3 / sec.

Aral Sea Information and Facts

The Aral Sea is an endorheic lake lying between the Aktobe and Kyzylorda regions of Kazakhstan and the Karakalpakstan autonomous region of Uzbekistan. Once known as the 4th largest lake in the World, the Aral Sea is famous today as one of the worst environmental disasters in the World.

Geology and Formation

The massive lake was formed 5.5 million years ago, following a fall in sea level coinciding with the uplift of the surrounding Elburz and Caucasus Mountains. One of the lake’s two main tributaries, the Amu Darya didn’t flow into the depression that now forms the Aral Sea until the start of the Holocene. Beforehand, it made its way into the Caspian Sea through the Uzboy Channel. The lake’s other tributary, the Syr Darya, formed an expansive lake in the Kyzyl Kum during the Pliocene period, which was known as the Mynbulak depression.

The Aral Sea depression was formed at the end of the Neogene Period. The basin was filled partially only later with water and only a part of the water came from the Syr Darya. At the end of the Pleistocene epoch and the start of the Holocene (somewhat 12,000 years ago) the depression was submerged entirely for the first time by the Amu Darya, which changed its course from the Caspian Sea to the Aral Sea.

Hydrology and Climate before its Shriking

The Aral Sea used to be the fourth largest lake in the world, after the Caspian Sea, Lake Superior and Lake Victoria. The Aral Sea drainage basin is located mainly in Uzbekistan, but also in parts of Tajikistan, Turkmenistan, Kyrgyzstan, Kazakhstan and Afghanistan.

Before its downfall in 1960, it had brackish waters, its salinity never exceeded 12 grams/kilogram and the water mass of the lake was homogenous. The vertical stratification of the lake’s temperature was usually strong, as the temperature of the bottom area was a constant 2-4OC throughout the year, and the near-surface temperature was between 23-25 degrees Celsius in the summer, thus forming a steep thermocline at a depth of 20-30 meters. This means that the density fields of the lake were merely influenced by water temperature and not its concentration of salinity. With an overall average content of oxygen of 6.3 ml/l, the Aral Sea was oversaturated with oxygen.

Before the desiccation of the Aral Sea, the lake actually played a big part in the local climate, regulating it by softening strong Siberian winds during the winter and cooling the area during the hot summer months. The local climate is considered a desert-continental one, with wide-ranging temperatures, hot summers, cold winters and infrequent rainfall. The annual rainfall is estimated to being 100 mm.

Naval History

The Russian presence at the Aral Sea began in 1847 with the founding of the small town of Aralsk, close to the mouth of the Syr Darya. The Navy of the then Imperial Russia deployed its vessels on the huge lake, and since it wasn’t directly connected to other bodies of water, the ships were disassembled in Orenburg and were shipped nearly 1000 kilometers overland to the city of Aralsk, to be reassembled once again.

The first ships deploying on the lake were the war ship Nikdai and the merchant vessel Mikhail, the latter serving the fisheries of the Aral Sea. Beginning in 1848, these two vessels surveyed the entire Aral Sea during a course of two years. Taras Shevchenko, an exiled Ukrainian poet and painter participated in this expedition, and produced some of the first paintings of the coast of the Aral Sea.

In 1851 two new steamers arrived to the lake from Sweden, conducting geological surveys of the region. Whilst the surveys concluded that no coal deposits were found in the area, the Military Governor General of Orenburg ordered a massive supply of saxaul, a kind of desert shrub, to be collected, but as it turned out, it wasn’t a suitable fuel.

History of Downfall

Before the 1960’s the Soviet Government decided to divert the two main water sources of the Aral Sea, the Amu Darya and the Syr Darya, with the goal of irrigating the desert, aiming to grow rice, melons, cereals and especially cotton in the dry land area. The plan was to grow massive amounts of cotton, so that it can be exported. This plan succeeded momentarily, since Uzbekistan became the largest exporter of cotton in the World in 1988.

The construction of huge and many irrigation canals began in the 1940s. The enormous irrigation network encompassed 20,000 miles of canals, 45 dams and more than 80 reservoirs. Though the plan initially seemed well-thought, many of the irrigation canals were extremely poorly built, allowing water to leak and evaporate. It is estimated that up to 70% of the water that went through the irrigation network has gone to waste.

By the start of the 1960s, 20-60 km3 of water were going to the land instead of into the Aral Sea each year. As virtually all the water supply was redirected, most of the sea’s water supply began to shrink. Until 1970 the Aral Sea’s level fell with an average of 20 centimeters each year, and this amount only increased to 80-90 centimeters per year by the 1980s. The amount of water taken from the rivers doubled between 1960 and 2000, as did the cotton production.

A prediction set in 1964 stated that the Soviets never cared about the state of the Aral Sea, and expected it to disappear. However, a project was proposed in the 1960’s that involved the redirection of a couple of inflowing rivers of the Ob Basin to Central Asia over enormous canal systems that would refill the Aral Sea. But negative public opinion and the huge cost of the project discouraged its by-standers and the project was abandoned by 1986.

By 1998 the surface of the Aral Sea shrank by 60% and its volume by an astounding 80%. It used to have a surface area of 68,000 km2 and a volume of 1,100 km3 in its glory days, before the 1960s. By 1998 it had shrunk to an area of 28,687 km2 and its salinity increased from 10g/l to 45 g/l. In 1987 the lake was split into two parts, North and South Aral Sea. As if the massive amount of water gone to waste wasn’t enough, crop rotation wasn’t used at all on the soil on which the cotton was cultivated. This meant that a lot of pesticides and fertilizers were used, which were transported by the runoffs of the fields into the shrinking Aral Sea, resulting in severe pollution and health problems in the area.

Environmental Crisis and Consequences

By 2003 the Aral Sea was vanishing in a fast pace. Its increase in salinity practically meant that the water became undrinkable. What’s worse, the deeper waters were much saltier than the water on the surface, and since it didn’t mix, the top of the lake evaporated rapidly. In the same year the South Aral Sea divided into a separate Eastern and a Western basin.

By 2004 the lake’s surface shrunk to 25% of its size (17,160 km2) and witnessed an increase in salinity that was five times its normal amount. By this time, most of the lake’s flora and fauna had been killed, including the once-abundant supplies of carp, sturgeon, barbell and roach. Merely three years later the lake shrunk to 10% of its size, and the South Aral Sea had a salinity of 100 g/l.

The receding sea left plains covered in salt and various toxic chemicals resulting from weapon testing, careless industrial projects, and fertilizers, Dust storms formed on the newly-exposed sea beds, which carried toxic dust contaminated with salt, fertilizer, pesticides and other chemicals. The ecosystems of the Aral Sea and the deltas which feed into it are nearly totally destroyed.

The land surrounding the lake is heavily polluted. The people living around the lake are faced daily with lake of fresh drinking water, as well as numerous health problems including lung disease, cancer, liver and kidney diseases. The Karakalpak population, which lived south of the Aral Sea, is hit the hardest. Infant mortality in the region is amongst highest in the World. The crops have all been destroyed by the salt which was deposited into the land. The Aral Sea fishing industry, which once numbered over 40,000 employees and produced 1/6th of the Soviet Union’s fish stock, is non-existent today. The small fishing towns have turned into ship graveyards with fishing boats scattered across the vast salt plains.

The dust storms carrying the numerous toxic chemicals caused colder winters and hotter summers in the area. The shrinking of the Aral Sea directly accounts for 50-65% of the warming trend in the area. Between 1960 and 2000 there has been a 2-6OC temperature increase, also causing a decrease in precipitation.

The area has witnessed desertification, which means that the land has been degraded in a manner that its natural resources cannot be used anymore. The vegetation has been reduced by 40%, resulting in intensified winds and, consequently, even more dust storms. An estimated 6 million hectares of agricultural land have been destroyed because of desertification.
Unfortunately, the salinity problem is hard to resolve. Re-watering small lakes which have lost their primary tributaries doesn’t compensate the high salinity which was obtained over the course of many years. A lake’s water budget is determined by many elements, including evaporation, precipitation rates, groundwater inflow, and inflow from rivers, among many other reasons.

Some researchers emphasize the fact that the desiccation of the Aral Sea is in part triggered by natural climate variability as well. Paleoclimatic reconstruction has shown that the Aral Sea has witnessed several similar shrinking episodes in the distant past, although no one can deny the impact of the massive irrigation project.

Overall, the lake has lost more than 90% of its water. Because of the desiccation, significant alterations can be seen in the lake’s chemical regime. The oxygen saturation has changed drastically between 1991 and 2002, which enhanced the density of vertical stratification. The salinity difference is as high as 12 g/l between the upper and lower parts of the lake. Because the vertical mixing and ventilation now became threatened, the bottom portion of the column turned anoxic and contains hydrogen sulfide.

But even before the desiccation of the lake, the Aral Sea had a unique salt composition, differing from oceans and salt lakes. During its desiccation, the salt composition of the Aral Sea has been subject to numerous changes because of chemical precipitation and salinity building. The first compounds to advance due to the salinity increase are calcium and magnesium carbonates, and the subsequent salinization has led to massive precipitation of gypsum as well. Because of the sudden changes in the physical and chemical conditions of the Aral Sea, severe consequences can be observed for the biological systems living in the lake.

Islands of the Aral Sea

The name “Aral” actually means “sea of islands”, and refers to the more than 1000 islands that once dotted the lake. Of all the islands, Vozrozhdeniya was one of the largest and its name means “Rebirth Island”. In 2001 the island turned into a peninsula, and a couple of years later it became part of the mainland, similar to other large islands, including Kokaral and Barsa-Kelmes.

In 1948 a secret Soviet bioweapons laboratory was funded on the island of Vozrozhdeniya, which today is a disputed territory between Kazakhstan and Uzbekistan. The laboratory was abandoned after the disintegration of the Soviet Union, and it is said to have been a site of production, testing and dumping of various pathogenic weapons.

Oil and Gas Industry at the Aral Sea

The Uzbek government and a number of international oil companies, such as LUKOil and Petronas, signed a production-sharing agreement, with the aim of exploring and developing oil and gas fields in the Aral Sea. The contract was signed in 2005. According to official sources, as of the 1st of June 2010, 500,000 m3 of gas has been extracted from the Aral Sea, from a depth of 3 km.

Potential Solutions

A number of possible solutions have come up over the years in aid of the current situation. Some of them include improving the quality of irrigation canals, installing desalination plants and dams to fill the Aral Sea, banning the use of chemicals around the lake and on the cotton fields, and even more radical possibilities, such as redirecting water from the Volga, Ob and Irtysh Rivers to fill up the lake. There have been talks of pumping sea water from the Caspian Sea through a pipeline, and diluting it with fresh water from the local catchment area.

Salvaging Initiatives

A working group based in the capital city of Pakistan, Islamabad, is working hard on saving the Aral Sea through their Aral Sea Basin Program, which has Kazakhstan, Uzbekistan, Tajikistan, Kyrgyzstan and Turkmenistan as members. Some of their objectives are rehabilitating the area around the lake, improving management of international waters of the lake basin and building a capacity of institutions at a local level to help advance the goals of the initiative. The group has made rescue efforts in 3 different phases as of today.

The actions of phase 1 were done with the involvement of the World Bank and lasted between 1992 and 1997. Since they focused more on the land than on the water usage upstream, and there were troubles of co-operation between people, this part of the rescue was unfortunately unsuccessful.

Phase 2 started in 1998 and lasted 5 years, in which the scheme drawn up by the World Bank didn’t take into consideration the opinion of local communities, thus being inefficient yet again.

In Phase 3 they came up with a new plan: to improve the irrigation systems that were already in function, and target water management at a local level. One of the largest efforts was made in order to recover the North Aral Sea, and a plan of connecting the West Aral Sea to the South Aral Sea through a dam across the Berg Strait was in discussion.

Thanks to this project, irrigation systems on the Syr Darya were improved. In October of 2003 the government released a plan to construct a concrete dam called Dike Kokaral. The project was completed in 2005 and thanks to it, water levels have risen, whilst salinity decreased. They managed to achieve an 8-meter rise from the previously constant 30 meters, but they still have a bit more to get to the viability level, which is 42 meters. The 13 kilometer long Kokaral Dam was completed by Kazakhstan, financed by the World Bank, allows water flowing in from the Syr Darya to accumulate, and helps restore the deltas and the wetland ecosystem of the Aral Sea.

A couple of significant fish stocks returned to the lake, which partly revived the fish industry and could lead to possible changes in the local microclimate. The North Aral Sea’s surface increased from 2,550 km2 in 2003 to 3,300 km2 in 2008.

The countries of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan also united for the ICWC in 1992, known as the Interstate Commission for Water Coordination of Central Asia. Their main objectives were management of the river basin, water allocation without any conflicts, introduction to automation into head structures, scientific research, interaction with hydro-meteorological stations and organized water conservation.

The IFAS, the International Fund for Saving the Aral Sea’s main objectives were raising funds to help in the project.

The Future of the Aral Sea

The South Aral Sea is currently largely abandoned, and only access water flowing in from the North Aral Sea is allowed into it. Some discussions are taking place about recreating the canal between the North and South Aral Sea, but political will is lacking. Attempts are being made of planting vegetation in the newly-exposed seabed, and plans have been made to redirect water flof from the Amu Darya to the Western basin, to salvage fisheries.

Today 200,000 tonnes of salt and sand are carried daily by the wind and are carried within a 300 kilometer radius. This decreases the available agricultural area and continues to destroy pastures, and create shortage of forage for domestic animals.

Documentaries

The condition of the Aral Sea was portrayed by the 1987 movie “Psy” (“Dogs”), directed by a Soviet filmmaker, detailing abandoned buildings and vessels throughout the lake. In 2000 the documentary called “Delta Blues” aired, depicting the problems the region faced because of the drying up. In 2007 BBC World transmitted a documentary called “Back from the Brink?” showcasing the changes witnessed in the region since the introduction of the Aklak Dam. In October 2013 the Al Jazeera broadcast a documentary in which it looked at the current situation of the people living around the lake.

Aral Sea Fish Species