142
10.3.5 Agricultural Water Use
In the valley, agricultural development and the well-being of the rural population
depend on the water availability in the transboundary small rivers (TSRs) and on the
fl ow regime of the Syrdarya River.
The agricultural sector constitutes the largest (consumptive) water user in the
valley. More than 90 % of water resources actually withdrawn out of 10–14 × 10
9 m
3 /
year are allocated to the agricultural sector.
According to Dukhovny et al. ( 2012 ), the share of water withdrawal from TSRs
and CDN for land irrigation in the valley in the last decade is, respectively, on average 26 and 2.7 %. The water withdrawal from TSRs in the Uzbek part of the valley
is as high as 86 %, because 62 % of the irrigated lands of the valley are located in
the provinces of Uzbekistan (Jaloobayev 2007 ). The highest share of water withdrawal from CDN in the valley occurs in provinces located downstream.
Supported by the materials of the Institute of Hydrogeology and Engineering
Geology, the Central Asian Scientifi c Research Institute of Irrigation, SANIIRI
( 2008 ) has assessed the annual groundwater resource in the valley to be 8.2 × 10
9 m
3 /
year, of which about 1.3 × 10
9 m
3
/year and 1.9 × 10
9 m
3
/year are annually used for
drinking and irrigation (including pumping by the vertical drainage wells during
non-vegetation period) purposes.
Well balanced in the Soviet era, centrally planned water resource distribution
amongst riparian countries changed after gaining the independence and thus
required improvements. Consequently, a legal framework for cooperation on the
Syrdarya River was put into place in the early 1990s (Dukhovny 2010 ).
However, looking at the then agreed arrangements on water allocation, these
have not been fully implemented to present, or it has proven impossible to agree
on water allocation. One limiting factor is that the energy sector (e.g. hydropower)
is not addressed by the existing regional organisations engaged in water management cooperation (Rakhmatullaev et al. 2010 ). Therefore, water supply in FV is
not sustainable due to the non-inclusion of the hydropower regime of Naryn and
Syrdarya Rivers.
10.4 Ecological Impact of Water Management and Irrigation
Practices
Environmental quality issues are signifi cant in relation to irrigated agriculture.
Subsurface drainage water quality refl ects the groundwater quality and soil water
constituents of the soil being drained. Because of the soil salinisation, ineffi cient irrigation and inadequate drainage, large amounts of water are annually withdrawn from
the rivers for land washing (the so-called salt leaching). This activity implies considerable volumes of return water containing salts, agrochemicals and trace elements to
rivers and streams associated with the discharge of the CDW.
S. Kenjabaev and H.-G. Frede
10.3.5 Agricultural Water Use
In the valley, agricultural development and the well-being of the rural population
depend on the water availability in the transboundary small rivers (TSRs) and on the
fl ow regime of the Syrdarya River.
The agricultural sector constitutes the largest (consumptive) water user in the
valley. More than 90 % of water resources actually withdrawn out of 10–14 × 10
9 m
3 /
year are allocated to the agricultural sector.
According to Dukhovny et al. ( 2012 ), the share of water withdrawal from TSRs
and CDN for land irrigation in the valley in the last decade is, respectively, on average 26 and 2.7 %. The water withdrawal from TSRs in the Uzbek part of the valley
is as high as 86 %, because 62 % of the irrigated lands of the valley are located in
the provinces of Uzbekistan (Jaloobayev 2007 ). The highest share of water withdrawal from CDN in the valley occurs in provinces located downstream.
Supported by the materials of the Institute of Hydrogeology and Engineering
Geology, the Central Asian Scientifi c Research Institute of Irrigation, SANIIRI
( 2008 ) has assessed the annual groundwater resource in the valley to be 8.2 × 10
9 m
3 /
year, of which about 1.3 × 10
9 m
3
/year and 1.9 × 10
9 m
3
/year are annually used for
drinking and irrigation (including pumping by the vertical drainage wells during
non-vegetation period) purposes.
Well balanced in the Soviet era, centrally planned water resource distribution
amongst riparian countries changed after gaining the independence and thus
required improvements. Consequently, a legal framework for cooperation on the
Syrdarya River was put into place in the early 1990s (Dukhovny 2010 ).
However, looking at the then agreed arrangements on water allocation, these
have not been fully implemented to present, or it has proven impossible to agree
on water allocation. One limiting factor is that the energy sector (e.g. hydropower)
is not addressed by the existing regional organisations engaged in water management cooperation (Rakhmatullaev et al. 2010 ). Therefore, water supply in FV is
not sustainable due to the non-inclusion of the hydropower regime of Naryn and
Syrdarya Rivers.
10.4 Ecological Impact of Water Management and Irrigation
Practices
Environmental quality issues are signifi cant in relation to irrigated agriculture.
Subsurface drainage water quality refl ects the groundwater quality and soil water
constituents of the soil being drained. Because of the soil salinisation, ineffi cient irrigation and inadequate drainage, large amounts of water are annually withdrawn from
the rivers for land washing (the so-called salt leaching). This activity implies considerable volumes of return water containing salts, agrochemicals and trace elements to
rivers and streams associated with the discharge of the CDW.
S. Kenjabaev and H.-G. Frede