The Disappearing Aral Sea

For most of the last ten thousand years the waters of the Amu Dar'ya and the Syr Dar'ya rivers have flowed through the deserts of south central Soviet Asia to the Aral Sea—actually a lake having no outlet. Formed in the high mountains to the southeast of the Aral, these rivers have a combined average annual flow of 111 cubic kilometers (km3), or 90 million acre-feet (maf). (In comparison, the Colorado River, which is formed in the Rocky Mountains and drains some of the most arid areas of the United States, has an average annual flow of only about 13.5 maf.) Until around 1960, about half of this water replenished the Aral Sea; the rest evaporated, transpired, or filtrated into the ground either naturally as the rivers flowed through the deserts and their deltas or as a result of diversions for irrigation and other human uses. During the preceding half century, inflows to the sea were just sufficient to offset the desert's high net evaporation rates. The size of the Aral remained relatively stable at about 68,000 square kilometers (km2), making it the world's fourth largest lake in area.

The region's relatively flat topography and easily tilled soils are conducive to irrigation, which purportedly dates back several millennia. Indeed, irrigation in this region supported one of the world's earliest civilizations perhaps as early as six thousand years ago. By 1900, more than 3 million hectares (7.4 million acres) were irrigated. By 1960, about 5 million hectares (12.4 million acres) had been brought under irrigation.

The size of the Aral Sea was little affected by this increased water use; the level of the sea fluctuated less than 1 meter between 1910 (when accurate measurements were first made) and 1960. Increases in the consumptive use of water for irrigation and other uses up to that time were largely offset by reductions in evaporation, transpiration, and filtration from the rivers and their deltas.

Over the last three decades, however, the balance that had maintained the level of the Aral Sea has broken down under a relentless drive to expand cotton production in the area around the sea. The Karakum Canal, for which construction started in 1954 and which now extends 1,300 km westward from the Amu Dar'ya, was a centerpiece of Soviet plans to expand cotton production in the central Asian republics. Diversions of water to this canal alone, all of which were lost to the Aral, rose from 1 km3 in 1956 to 14 km3 in 1986. By 1987 aggregate diversions through the Karakum Canal totaled 225 km3, equivalent to 60 percent of the water currently stored in the Aral Sea. (Annual diversions to the canal are now equivalent to nearly 85 percent of the virgin flow of the Colorado River.)

Soviet planners recognized that their efforts to expand irrigation would adversely impact the Aral Sea. They failed, however, to anticipate other consequences of their actions that have precipitated one of the greatest ecological disasters in history. Expansion of irrigation and the recession of the Aral Sea have resulted in huge dust storms, declining agricultural productivity, and sharply rising mortality and morbidity rates. Even the region's climate is apparently becoming less hospitable to crops and humans.

As the sea recedes, large areas of the former lake bottom have been exposed. The concentration of toxic salts in the upper layer of the exposed seabed and the lack of water and nutrients make it extremely difficult to establish a stabilizing plant cover. Without such a cover, dust storms blow up. These storms, which appear to be increasing in frequency and magnitude, transport an estimated 43 million metric tons of salts per year over vast areas, including the area's irrigated lands. Sodium chloride and sodium sulfate, which are particularly toxic to plants, are among the salts being carried from the former seabed.

High salt levels in the region's soils and water are also affecting agriculture. Although the soils are naturally saline, if there is adequate drainage salts can be leached from the soils by applying water in excess of that needed by plants. While the quantities of water applied to crops in the area are well in excess of crop requirements, the drainage is often very poor. Consequently, excess water, which is much more saline than the irrigation water applied, accumulates and raises the level of the groundwater table. As the water table rises into the root zone, the crops suffer from curtailed oxygen supplies. Moreover, capillary action draws salts from the shallow groundwater tables upward toward the surface. As the water evaporates, high concentrations of salt are left near the surface, largely destroying the agricultural potential of the land. Soviet research suggests that 60 percent of the irrigated soils in Uzbekistan, 80 percent in Turkmenistan, 35 percent in Tadzhikistan, 40 percent in Kirghizia, and between 60 and 70 percent in Kazakhstan suffered moderate to strong salinity problems in 1985.

Increasing salinity is an important factor in the recent decline in cotton yields. Reported average cotton yields in the five central Asian republics declined from 2,840 kilos (k) per hectare for the period 1976–1980, to 2,610 k for 1981–1985, to 2,400 k in 1986, and 2,300 k in 1987. Despite efforts to boost yields by increasing the amount of fertilizer applied, yields in 1987 had dropped to 81 percent of the average annual yield for the years 1976 through 1980. In 1987, 7 percent less cotton was produced on 15 percent more land compared with the 1976–1980 averages.

Perhaps the greatest sacrifices associated with the development of cotton have involved the health of the area's population. Drinking water supplies, especially in the lower reaches of the river basins, are contaminated by pesticides used in cotton production and by high salt concentrations. Pesticides have even been detected in mothers' milk. The deterioration of health conditions is evident in statistics: over the last fifteen years, the incidence of typhoid fever increased almost 30 times, hepatitis increased 7 times, and kidney disease, gallstone ailments, and chronic gastritis have all increased markedly. The incidence of cancer of the esophagus is 50 times the world average, and tuberculosis has reached epidemic rates. Infant mortality is more than 50 per 1,000 in the region as a whole, more than twice the reported rate of 23 per 1,000 for the Soviet Union. In one region of the Karakalpak Republic, located in the lower reaches of the Amu Dar'ya, child mortality is 110 per 1,000. One survey found 80 percent of the women suffering from anemia and 70 percent of the children ill.

As the Aral Sea recedes, the climate of the surrounding region is also being affected. Large water bodies have a moderating effect on the neighboring climate. Studies indicate that the decline in the size of the Aral Sea has been accompanied by more extreme temperatures—summers have become hotter, winters colder, and growing seasons shorter. Average May temperatures at Kungrad, currently located about 100 kilometers south of the Aral in the Amu Dar'ya Basin, were 3.0 to 3.2 degrees Celsius higher during the 1960–1981 period than during the previous twenty-five years. October temperatures, on the other hand, were 0.7 to 1.5 degrees Celsius higher during the more recent period. The growing season, the period between the last spring frost and the first fall frost, declined by ten days in the northern reaches of the Amu Dar'ya Basin.

The problems confronting the Aral Sea region were the subject of an international symposium entitled The Aral Crisis: Causes, Consequences, and Ways of Solution, held in October 1990 in Nukus in the Karakalpak Autonomous Soviet Socialist Republic. The author was a participant in these discussions. One result of the symposium was that participating scientists from the central Asian republics unanimously approved a resolution requesting the Supreme Soviet of the USSR to declare the lower reaches of the rivers in the Aral Basin to be ecological disaster areas, and urging immediate measures to improve the health of the region's population and to stabilize the level of the Aral Sea.

Improving the quantity and quality of potable water supplies and restricting the use of pesticides and fertilizers in the region are among the priorities of these Soviet scientists for improving health conditions there. Drinking water supplies in Nukus and Muynak should improve when a 200-kilometer pipeline, to cost an estimated 200 million rubles (about $350 million at the official exchange rate), is completed. The pipeline will bring water from a reservoir located above the irrigated lands that contribute most of the chemicals to the water.

To this participant in the symposium, an important part of any program to improve the health conditions should be a reduction in the use of pesticides—especially the defoliants used to facilitate cotton harvesting. Continuous cotton production has depleted soils and encouraged larger chemical applications in a futile effort to maintain yields in the Aral region. Rotation of crops might be one way to maintain yields and reduce the use of agricultural chemicals. Since cotton requires much higher concentrations of pesticides than any other crop, permanently shifting some of the land now in cotton to other crops would also reduce the use of agricultural chemicals.

In their resolution, the scientists at the Aral crisis symposium concluded that ecological restoration of the region is impossible unless the area of the Aral Sea is stabilized. Their proposals for increasing water flows to the sea include the imposition of strict limits on the water diverted by each republic, the introduction of water-conserving techniques in all areas of the economy, limiting the production of rice (a crop that uses particularly large quantities of water), removal of low-yielding land from cultivation, and reassessment of the use of reservoirs and drainage-collection ponds that lose 5 km³ or more of water annually to evaporation.

The resolution of the scientists was also notable because it did not support many of the costly structural proposals of some of the symposium speakers. One such proposal called for lining the dirt irrigation canals—which often lose 20 percent or more of their water to filtration—with concrete. This would save water (albeit at a high cost) where the seepage ends up collecting in and evaporating from local depressions and desert lakes; however, in other locations water seeping from an unlined canal may return naturally to the river and to an irrigation system downstream, or to a usable aquifer. Where filtration from canals and high water-application rates are raising groundwater tables and causing water-logging, the conjunctive management of surface and groundwater might reduce salinity problems and improve overall irrigation efficiency. Soviet assessments suggest that groundwater use could be increased by about 10 km3 annually without reducing river runoff. Detailed knowledge of the region's surface and groundwater hydrology is needed to target where the lining of canals or other schemes might be useful in improving water-use efficiency.

The Aral crisis symposium resolution identifies problems and needed changes but provides little insight as to how water-conserving technologies, altered cropping patterns, and other proposed reforms are to be brought about. Misguided central planning is cited as the cause of the Aral crisis. Yet the symposium scientists seem to expect that this same system, with adjustments in planning strategies, will solve the region's problems. Such expectations appear to be unrealistic; more fundamental changes in the economic system may be required.

Microeconomic planning and resource allocation by government fiat have rarely been successful, and some of the Soviet Union's biggest failures have been in the agricultural sector. Dictating what crops to grow and how much, and when water is to be applied, is a proven recipe for low productivity and wasted resources. One of the most persistent lessons to be learned from agricultural studies worldwide is that farmers tend to be efficient managers of their own resources within the context of the incentives, institutional constraints, and technologies by which they operate. Government policy is best directed to changing incentives to better reflect broad social directives and resource scarcities, to removing unnecessary constraints on farmers' decisions, and to expanding the available technologies rather than attempting to micromanage farms.

Unfortunately, market economies such as the United States do not provide an ideal model for the Soviet Union to emulate. Market and centrally planned economies alike tend to treat water as a free resource, and fail to internalize the full social costs of using environmentally damaging inputs such as pesticides. Underpricing of water, uncompensated environmental costs associated with its use, and wasted opportunities for transferring scarce supplies to higher-value uses in response to changing conditions underlie most water problems worldwide.

Nevertheless, there are fundamental differences between the two systems, and the Soviets could learn some important lessons from market economies. Although producers' costs in the United States may not fully reflect social costs, at least most irrigators here pay something for water (based on delivery and treatment costs) and chemicals. Moreover, production decisions in the United States are motivated by profit incentives and are usually based on an intimate knowledge of local conditions. In the Soviet Union, on the other hand, the expansion of irrigation, the selection of crops, and the allocation of water within the Aral Basin have been dictated by planners far removed from the basin and the outcome of their decisions. Soviet farmers are motivated by production targets. They apply more water and chemicals, which apparently have been readily available to the region's collective and state farms, as long as these inputs are expected to increase production. The people who actually manage the water, plant the crops, and apply the chemicals have little or no incentive to adopt more efficient and benign practices.

Soviet leaders have recognized the failures of their system and are debating how to introduce market incentives. Farmers in the Aral Basin have recently been permitted to lease small plots for their own use. Although a step in the right direction, this will have little impact on the region's basic problems as long as the majority of the land stays in huge collective and state farms subject to centrally established production goals.

Extreme poverty and abysmal health conditions characterize the Aral Sea region. And conditions continue to deteriorate as the sea vanishes, crop yields decline, salts and pesticides accumulate in the water and soil, and the region's population of nearly forty million increases rapidly. Structural approaches alone will not solve these problems, and the depressed state of the Soviet economy suggests that large new infrastructure investments will not be forthcoming soon. Major institutional reforms are needed to provide farmers of the Aral region with more latitude in selecting the crops they grow and the farming practices they employ, as well as to provide greater incentives for farmers to conserve water and to reduce chemical inputs in crop production.

One such reform could be the privatization of land. The government could give land, along with some short- and medium-term credit, to farmers. In return, the farmers would have to pay for the water and chemicals used and repay the loans within some reasonable period—say five years. Successful farmers would soon be in a position to purchase more land from those unable to repay their loans. Gradually, the region's natural resources would move into the hands of the most able and enterprising managers, and its human resources would have greater opportunities and incentives to prosper.