沙漠研究 22-1, 171 -174 (2012 )"ICAL 1 / DT X"

Journal of Arid Land Studies－Refereed Paper－Seasonal Changes in Water Quality of Rivers and Ground Water
in Karakalpakstan, Uzbekistan
Yoshiko KAWABATA*1), Mayuko KAWAI2), Masaaki YAMADA3), Siaw ONWONA-AGYEMAN3),
Vyacheslav APARIN4), Berdiyar JOLLIBEKOV5), Tomoko KURITA2),
Masahiro NAGAI6) and Yukio KATAYAMA6)
Abstract: The study investigates the seasonal changes in the chemical characteristics of river water and ground water inKarakalpakstan, Uzbekistan from August 2008 to September 2010. The results indicate that major ion concentrations of groundwater were higher than Amu-Darya river water, and NO32- concentration in winter were higher than other seasons.
However river water and ground water showed different trends. Particularly, NO32- concentrations of ground water in the winterseason of 2009 were higher than 2010. In summer 2008, water volumes of Amu-Darya were extra lower than other years, which
possibly resulted in higher concentrations for this particular summer.
Key Words: Central asia, Seasonal change, Uzbekistan, Water quality

1. Introduction
Access to safe drinking water is essential to the health of
the human beings. It is a component of the effective healthprotection policy, and it is also a development issue at national,
regional and local levels.
Aral Sea Problems is one of the big environmental
problems in the world. The Aral Sea is an inland lake and has
2 inflow rivers, Amu-Darya and Syr-Darya. The decrease inAral Sea area was caused by the large scale irrigated agriculture
which started in the 1950’s, especially in the Aral Sea basin. Asa result, many villages were built in the area and people started
producing rice, cotton, wheat, and vegetables.
However, after the Soviet era, Amu-Darya and Syr-Darya
became international rivers and water problems had occurredin upstream countries and downstream countries.
Karakalpakstan is located in the most downstream along
Amu-Darya and experiences drought once every several years.
Ground water or river water is their main source ofdrinking water in this area. The gradual climate change overthe centuries was accelerated by the Aral Sea ecologicaldisaster of the late 20th century in Aral Sea basin, especially
Karakalpakstan. By determining EC values, Papa et. al.
(2004) conducted research on the effect of salinization causedby large-scale irrigation. Crosa et. al. (2006a) analyzed
pesticides in the Amu-Darya basin and reported about
identifying compounds with a high risk of contamination.
We investigated about the uranium concentration of drinking
water in the villages of the central parts of Uzbekistan andKazakhstan (2006) and found that the results exceeded theguideline level for drinking water prescribed by WHO (2008).
However no work has been carried out on the seasonalchanges in water quality. Therefore, we investigated theseasonal changes in chemical characteristics of river water andground water and compared between drought years and normalyears in Karakalpakstan. However, our study did not include
the seasonal change of water quality. Therefore, weinvestigated the seasonal changes in chemical characteristics ofriver water and ground water in Karakalpakstan, and comparedwith streamflow and precipitation.

2. Materials and Methods
Water samples were collected from river water and groundwater from 2008 to 2010. At G-staiton and A-station, watersamples were collected every month from 2008 August toSeptember 2010. In Karakalpakstan, ground water samples
and river water samples were every month from August 2008
to 2010.
The sampling sites are shown in Figure 1. The positionof each sampling spot was determined by using an eTrex
Legend portable Global Positioning System (GARMIN Ltd.,Japan).
Water samples were filtered through a 0.45 µm Membranefilter (DISMIC 25AS020AS, ADVANTEC Corporation) andcollected in polypropylene bottles. PO43-, Cl-, NO32-, SO42-,Na+, NH4+, K+, Mg2+ and Ca2+, and concentrations were
determined using an LCA-10A ion chromatographic analyzer(Shimadzu Corporation, Japan). Finally, accuracy and* Corresponding Author E-mail: yoshikok@cc.tuat.ac.jp Phone/Fax: +81-42-388-7618
Postal postal address: 2-24-16, Nakacho, Koganei, Tokyo 184-8588 Japan
1) International Center, Tokyo University of Agriculture and Technology, Japan

4) Hydrogeology and Engineering Geology Institute, Republic of Uzbekistan

2) Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Japan

5) Karakalpak branch of the Uzbek Academy of Science, Republic of Uzbekistan

3) Institute of Agriculture, Tokyo University of Agriculture and Technology, Japan6) Faculty of Human Environment, University of Human Environments, Japan

Table 2. Seasonal change of Amu-Darya. Notes: n.d.: not detected

Fig. 1. Sampling sites in Karakalpakstan, Uzbekistan.
Table 1. Major ion and nutrient concentrations in Karakalpakstan.
Notes: n.d.: not detected

precision of the analytical methods used here were tested using
Anion Mixed Standard Solution IV and Cation Mixed
Standard II for ion chromatography (Kanto Chemical Co.,
Japan) and shown to be satisfactory with 2-5% error.

3. Results and Discussion3.1. Major ion and nutrient concentrations
Major ion and nutrient concentrations (PO43-, Cl-, NO32-,SO42-, Na+, NH4+, K+, Mg2+, Ca2+) are shown in Table 1.
Major ion concentrations and nutrient of Amu-Darya
followed the same trend in this area. However, the results
were different for ground waters. With the exception of G3,
NH42- was identified in the other ground water supplies. This
result indicates that ground waters were contaminated bysewage.

Fig. 2. Seasonal change of ion concentration of Amu-Darya water.

3.2. Seasonal changes in water quality of river and groundwater
We collected Amu-Darya river water from A-station andground water from B-station. Seasonal changes of riverwater are shown in Table 2 and Figure 2. Maximum
concentrations of major ions were detected in April. This
increase in the ion concentrations can be attributed to themelting of snow during this period, which is a common
phenomenon.
However, nutrient concentrations showed a different trend.
Seasonal changes in these concentrations were not assignificant as the major ions, although concentrations of NO32from November to June were higher than other seasons. This
was not the agricultural season in Karakalpakstan, so nutrients
could not have emanated from agriculture areas.
In summer 2008, water volumes of Amu-Darya were extra
lower than other years. Therefore, it was compared withseasonal change of river water and precipitation amount (Fig. 3).
In Karakalpakstan area, many agriculture fields were not able
to produce crops in 2008. In particular, rice fields in theseareas were unproductive. However, rice cultivation waspossible in 2009 due to the abundance of water inKarakalpakstan.
Precipitations in Karakalpakstan wereconstantly low during the period 2008-2010. Karakalpakstan
is an arid area, therefore, precipitation was not a big factor foragriculture. Crosa et. al. (2006b) suggested the great
irrigation and drainage infrastructure inherited from the timesof the Soviet Union had proven difficult to maintain, resulting
in shortage of water with a chemical composition suitable forhuman use. They also reported that salinity at the upstreamsite (Termez) is reduced during the period from May toSeptember. This same trend was also revealed in our study.
Two main driving forces act in shaping the seasonalvariation of the salinity of the Amu Darya River: low naturaldrainage density of the catchment, which limits the salt loads
induced by the natural runoff processes, and the snow andglacier melting in the upper catchment area which promotedissolved salt dilution during the high-flow period (Spring andSummer). Upper stream countries, Kyrgyz and Tajikistan areplanning to construct hydroelectric generating plants. If theseplans are carried out, more serious problems may appear in
Karakalpakstan areas.
In this region, an important factor for agriculture is thevolume of the river water other than precipitation. Thus, we
tried to compare river water quantity and quality (Fig. 4).
Seasonal changes in river water quantity were almost low.
Especially, river water was used for irrigation in agriculture
seasons (from April to September). As Karakalpakstan areas
are located in the downstream of Amu-Darya, they depend
mostly on river water for irrigation, and river water was lessconsidered in agriculture season. However, river water
volumes in 2010 were abundant so agricultural yield in 2010
was very high. However, a lot of people in karakalpakstan
must go away to work. Getting a stable income fromagricultural is considered to be difficult as a result of frequent
drought occurrences in the region once every few years.
Therefore, there is the need for reforms to set up irrigation
systems that will ensure a shift towards sustainable irrigation
agriculture.
Seasonal changes of ground water were shown in Table 3
and Figure 5. Maximum volumes of major ions andnutrients depended on each ion. The ground waters weremuch affected from soil than river water. Seasonal changes
were not high than Amu-Darya river water and were relatively
constant. SO42- concentrations of ground water samples andriver water samples were higher than other ions. These
results were caused by soil components.
However,
concentrations of ions in summer were higher than winter.
This result was different from Amu-Darya river water.
As for salinity, for which an exhaustive analysis will be
proposed subsequently, more than 50% of the observations
exceeded the value of 1000 mg/l, which is considered as theFig. 3. Seasonal changes in precipitation amount at Nukus

Fig. 4. Seasonal change of streamflow amount of Amu-Darya river.

Table 3. Seasonal change of ground water.

Notes: n.d.: not detected

4. Conclusion
The results indicate that major ion concentrations of groundwater were higher than Amu-Darya river water, and NO32concentration in winter were higher than other seasons.
However river water and ground water showed different trends.
Particularly, NO32- concentrations of ground water in the winterseason of 2009 were higher than 2010. In summer 2008,
water volumes of Amu-Darya were extra lower than otheryears, which possibly resulted in higher concentrations for thisparticular summer. Agricultural yield in 2010 was very good.
However, a lot of people in karakalpakstan must go away towork. Getting a stable income from agricultural is considered
to be difficult as a result of frequent drought occurrences in theregion once every few years. Therefore, there is the need forreforms to set up irrigation systems that will ensure a shift
towards sustainable irrigation agriculture.

Acknowledgments
The authors are grateful to Profs. Hirozumi
WATABANABE and Izumi WATANABE for their advices.
This work was supported by Grant-in-Aid for Science
Research, the Ministry of Education, Culture, Sports, Scienceand Technology of Japan, 2010 (Monbusho International
Scientific Research Program No.20405004, represented by
KAWABATA, Y.).
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Fig. 5. Seasonal change of ion concentration of ground water in Nukus.

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