138
tries (Uzbekistan, Kazakhstan and Turkmenistan) were suitable for practising
irrigated agriculture and for growing water-intensive agricultural crops (cotton, rice,
cereals, etc.).
As a consequence, irrigated lands for agricultural production, particularly in the
Uzbek part of the valley, expanded rapidly, mainly for cotton monoculture (Kandiyoti
2005 ). These expansions resulted in the development of lands in the Central Fergana
(Laktaev and Ermenko 1979 ) and promoted the construction of a number of large
main canals and CDN within the command area of the Big Fergana Canal (BFC),
South Fergana Canal (SFC) and North Fergana Canal (NFC) as well as
Akhunbabayev’s Canal, Big Andijan Canal (BAC) and Big Namangan Canal (BNC)
(Fig. 10.5 ). These led to the improvement of irrigation infrastructure and changes to
the Syrdarya River fl ow regime. Due to these constructions, 92 % of the Syrdarya
River’s fl ow was regulated (Toryanikova and Kenshimov 1999 ).
The length of inter-farm canals in the valley is 10,474 km (Table 10.2 ), of which
5010 km are lined to reduce seepage. The on-farm network has a total length of
53,570 km, and only 18 % of which is lined.
The irrigation infrastructure is in a poor condition and much of it is worn out.
Considering the low effi ciency of the irrigation system in FV, ranging from 55 % in
the Fergana province to 63 % in Namangan province (Ikramov 2007 ), main and
inter-farm canals require reconstruction and anti-seepage measures. Existing regulation structures need to be rehabilitated and new ones constructed; outlet structures
and fl ow measurement stations also need to be constructed. Measures to improve
the operation and management system of the irrigation infrastructure are also
needed. The on-farm network is very complex, passing through settlements, and is
frequently lined with trees, which complicates construction/reconstruction work.
10.3.3 Collector-Drainage Network
The expansion of the irrigated lands in the valley from 675,000 ha in 1932 (Irrigation
of Uzbekistan 1975 ) to 1,572,970 ha in 2010 (CAWATERinfo 2012 ) has resulted in
increasing water withdrawal from main rivers and induced the problems of land
degradation and contamination of the Syrdarya River water resources. In their natural state, many of these lands are poorly drained. Therefore, intensive development
of irrigated lands in the second half of the twentieth century increased irrigated lands
with an artifi cially drained area by about 685,834 ha. About 70 % of the CDN out of
a total length of 31,654 km is on farm. In total, 2861 operating vertical drainage
wells, including provisions for running the pumps and surface drains to dispose the
excess of water, were built in the valley as a network to lower the groundwater level.
These drainage wells are mainly installed in areas with high soil permeability and
preferably fresh groundwater that can be reused for irrigation. Consequently, this
system is operation and maintenance intensive and requires a continuous electrical
power supply. Therefore vertical drainage, a complicated engineering complex, was
not used at full capacity after the collapse of the Soviet Union.
S. Kenjabaev and H.-G. Frede
tries (Uzbekistan, Kazakhstan and Turkmenistan) were suitable for practising
irrigated agriculture and for growing water-intensive agricultural crops (cotton, rice,
cereals, etc.).
As a consequence, irrigated lands for agricultural production, particularly in the
Uzbek part of the valley, expanded rapidly, mainly for cotton monoculture (Kandiyoti
2005 ). These expansions resulted in the development of lands in the Central Fergana
(Laktaev and Ermenko 1979 ) and promoted the construction of a number of large
main canals and CDN within the command area of the Big Fergana Canal (BFC),
South Fergana Canal (SFC) and North Fergana Canal (NFC) as well as
Akhunbabayev’s Canal, Big Andijan Canal (BAC) and Big Namangan Canal (BNC)
(Fig. 10.5 ). These led to the improvement of irrigation infrastructure and changes to
the Syrdarya River fl ow regime. Due to these constructions, 92 % of the Syrdarya
River’s fl ow was regulated (Toryanikova and Kenshimov 1999 ).
The length of inter-farm canals in the valley is 10,474 km (Table 10.2 ), of which
5010 km are lined to reduce seepage. The on-farm network has a total length of
53,570 km, and only 18 % of which is lined.
The irrigation infrastructure is in a poor condition and much of it is worn out.
Considering the low effi ciency of the irrigation system in FV, ranging from 55 % in
the Fergana province to 63 % in Namangan province (Ikramov 2007 ), main and
inter-farm canals require reconstruction and anti-seepage measures. Existing regulation structures need to be rehabilitated and new ones constructed; outlet structures
and fl ow measurement stations also need to be constructed. Measures to improve
the operation and management system of the irrigation infrastructure are also
needed. The on-farm network is very complex, passing through settlements, and is
frequently lined with trees, which complicates construction/reconstruction work.
10.3.3 Collector-Drainage Network
The expansion of the irrigated lands in the valley from 675,000 ha in 1932 (Irrigation
of Uzbekistan 1975 ) to 1,572,970 ha in 2010 (CAWATERinfo 2012 ) has resulted in
increasing water withdrawal from main rivers and induced the problems of land
degradation and contamination of the Syrdarya River water resources. In their natural state, many of these lands are poorly drained. Therefore, intensive development
of irrigated lands in the second half of the twentieth century increased irrigated lands
with an artifi cially drained area by about 685,834 ha. About 70 % of the CDN out of
a total length of 31,654 km is on farm. In total, 2861 operating vertical drainage
wells, including provisions for running the pumps and surface drains to dispose the
excess of water, were built in the valley as a network to lower the groundwater level.
These drainage wells are mainly installed in areas with high soil permeability and
preferably fresh groundwater that can be reused for irrigation. Consequently, this
system is operation and maintenance intensive and requires a continuous electrical
power supply. Therefore vertical drainage, a complicated engineering complex, was
not used at full capacity after the collapse of the Soviet Union.
S. Kenjabaev and H.-G. Frede