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close this bookCentral Eurasian Water Crisis: Caspian, Aral, and Dead Seas (UNU, 1998, 203 pages)
close this folderPart II: The Aral Sea
Open this folder and view contents4. Creeping environmental problems in the Aral Sea basin
Open this folder and view contents5. the Aral Sea and socio-economic development
View the document6. Satellite image maps of the Aral Sea and Central Asia
Open this folder and view contents7. Voices from the region

6. Satellite image maps of the Aral Sea and Central Asia

Toshibumi Sakata

The Syrdarya, which runs through the northern base of the Tien Shan mountains, travels 3,000 kilometres to the Aral Sea. The Amudarya, which starts from the Kunlun mountains and runs north-west through the Pamir Heights into the Aral Sea at its south shore, has a river course of approximately 1,500 kilometres.

The Aral Sea, sitting close to and uphill from the Caspian Sea, has had a very interesting history of change. In ancient times, the Aral Sea presented a completely different landscape, either having been a part of the greater Caspian Sea or not having existed at all. During the Stone Age and the Bronze Age, there once existed a lake between the Caspian Sea and the Aral Sea. Today the Amudarya runs straight to the north, but it used to run to the west. The area south of the Aral Sea had been exposed for a long time to the shifting stream of the river, leading to the expansion of rich soil suitable for agriculture. People came and lived there, forming villages. Agriculture along the Amudarya had become prosperous, and a civilization developed in the Khorezm District. The Syrdarya runs into the Aral Sea on its eastern shore. Agriculture also developed along its banks. From the sixth century on, the irrigation system had expanded the cultivated area and promoted activities based on economic motivation, thus giving birth to some strong kingdoms. The Silk Road became popular and prosperous, and the region had become the base through which East-West trade was promoted and carried out.

Fig. 6.1 The change in the level of the Aral Sea: The shaded area represents shrinkage between 1986 and 1993 (Note: not to scale)

Today this region has a great stretch of agricultural land that straddles the banks of the Amudarya, presenting a view from a satellite as if it were a huge elongated oasis in the middle of a desert. As a result of the Ground Truth Survey carried out in 1994, we have found that the land is good for agriculture if water is made available. For millennia, people have converted desert landscapes into agricultural land through irrigation. However, because of high evapotranspiration, these lands became salinized. In order to flush out those salts from the soil, drainage channels have had to be constructed, but these are quite inadequate at present. Generally speaking, the rise and fall of ancient kingdoms in this region depended to a great extent on control of water sources and courses. Since the 1960s, enormous efforts by the former Soviet regime to develop cotton fields along the Amudarya and Syrdarya basins have produced large quantities of cotton but also severe degradation of the land, mainly salinization. Furthermore, the construction of many irrigation canals has decreased the influx of water to the Aral Sea.

A general view of the Khorezm area by satellite imagery. The network of irrigation canals and the salinization of the surface soils are easily visible (Source: Landsat TM, 2/9/1987)

The Aral and Caspian basins (Source: Landsat TM, 1990, composed by TRIC, Tokai University Research and Information Centre)

The shrinking of the Aral Sea. Aral Sea in 1986. Right: Aral Sea in 1993. The growth of the inland island and the degradation of the coast are easily visible (Source: National Oceanic and Atmospheric Administration [NOAA]. 4/9/1980)

The shrinking of the Aral Sea. (Source: NOAA, 9/7/1993)

Satellite image map of Central Asia (Source: Landsat thematic mapper [TM], 1990, composed by TRIC, Tokai University Research and Information Centre)

The Aral Sea of today presents a miserable picture, having lost almost half of its area of the 1960s. According to the analysis of data obtained by satellite, the Aral Sea could disappear some time in the twenty-first century.