3. Water resources of Uzbekistan
33
Before the 1970s, the Amu Darya branched into a number of
tributaries that emptied into the Aral Sea through an extensive delta.
However, the Soviet government began diverting massive amounts
of water from the river beginning in the 1950s to irrigate
cotton and
other crops grown in the river’s lower basin. The main section of the
Karakum Canal was completed in the 1960s to carry water from the
Amu Darya at Kerki, Turkmenistan, westward to Mary and Ashgabat.
The diversion of water from the Amu Darya for irrigation decreased
the amount of water entering the Aral Sea, which consequently
began shrinking. Increased irrigation on the hot, dry floodplains
of the Amu Darya and in adjacent regions resulted in evaporation
that left salt deposits that make the soil infertile. Surface runoff
transported these salts into surface waters and increased the salinity
of the Amdarya. By the 1990s the discharge of the Amu Darya into
the Aral Sea stopped for one to three months in most years. Lakes
and bogs dried up in the former Amu Darya delta, now far from the
sea’s shores, and the wetlands fed by the
river shrank to only a tiny
percentage of their former size.
It begins with the confluence of the rivers Pyandj and Vakhsh
in Tajikistan, and in the upper-reach it forms the border between
Tajikistan, Uzbekistan and Afghanistan. From the mountains it
flows into the desert lowlands of Turan through Uzbekistan and
Turkmenistan and drains into the Aral Sea. Along the main river
there are two reservoirs with hydroelectric power stations, re-
pre senting the main structures for management of water flow and
salinity, several distribution points to
serve irrigation water needs,
main and side inflows, including return flow, and water intake for
communal needs.
Next to the quantity of water allocated to the environ ment, its
quality is of equal importance. To conserve the remaining deltaic
lakes and semi-natural vegetation to the desired extent, a certain
amount of freshwater input is necessary.
Water allocated to the
environ ment consisting mainly of drainage. Severe alterations
to the hydrological regime of the Amu Darya River over the past
40 years have caused serious degradation of the environ ment in
the whole river basin and especially in river delta and Aral Sea
1
.
Desertification processes initiated by the continuous decrease in
river flow have significantly changed the ecosystems of the region.
The deltaic lakes, pastures
and riverine forests have been, and still
are, to a large extent, the means of existence for the local human
population. Their importance has even increased
with the loss of the
fishing industry in the Aral Sea. In this respect of major importance
1
Schluter M., Savitsky A.G., McKinney D.C., Lieth H. (2005) Optimizing long-
term water allocation in the Amudarya River delta: a water management model
for ecological impact assessment. Environm. Modelling Software 20 529-545
34
ENVIRONMENT, POLLUTION, DEVELOPMENT: THE CASE OF UZBEKISTAN
are approaches used for allocation of water resources and regulation
of them. Allocation of the Amu Darya and Syr Darya transboundary
water resources between the five states of the central Asia is
still based on existing quotas of the Soviet times at first covering
irrigation water needs. However amongst countries of the region
need for adjustments of the water resource
management is widely
accepted, considering changing needs in agriculture, the demands
of the ecosystems in the deltas and littoral of the Aral Sea, effects of
climate change, or other physical or socio-economic factors.
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