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Environmental problems of Northern Eurasia
The Aral Sea
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Conclusions
In geological terms, the Aral Sea has had a short history dating from the late
Pleistocene. Water levels have fluctuated by up to 36 metres throughout the Quaternary,
largely due to natural tectonic, climatic, and geomorphological influences, but human use
of water resources from the sea's two major tributaries, the Amudarya and Syrdarya, have
also played a role during the last few thousand years. The most significant human
intervention has come about in the second half of the 20th century as increasing volumes
of water have been diverted to irrigate cropland. As a consequence, the water level
declined by more than 15 metres between 1960 and 1990 when the Aral Sea became split into
two separate, increasingly saline lakes. The physical consequences of the rise in
irrigated area have been felt far beyond the shrinking Aral Sea and the deleterious
physical consequences for its biodiversity, its former coastline and delta areas. Eleven
new surface water bodies with capacities of 1 km3 and more have been created in
the basin as reservoirs and drainage sinks. The irrigated areas themselves have suffered
degradation in the form of salinization and waterlogging, while the excessive use of
agrochemicals has had feedback effects on ecology and human health. In other parts of the
Aral Sea basin, overintensive grazing, infrastructural development, and the
overexploitation of woody vegetation, principally for fuel wood, have further contributed
to desertification.
The Aral Sea basin has the unfortunate distinction of being one of the foremost
examples of environmental degradation and change induced by human society in the 20th or
any other century. Despite the recognition of this unenviable situation, efforts towards
environmental rehabilitation have been hampered by the political and economic changes that
have affected the area since the break-up of the Soviet Union in 1991.
<<< Overview of Desertification
Problems | Environmental Problems Index | Deforestation
and Degradation of Forests >>>
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