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Processing, interpretation and generalization of a database on the elemental composition of rivers and water bodies in the Aral Sea Basin

Project Status: 3 Approved without Funding
Duration in months: 36 months


The goal of the project is to fully process the prior Navruz database for determining geochemical composition of the samples of water, aquatic plants, bottom sediments and surrounding soils sampled in the main rivers of the Aral Sea basin, the Syr Darya, Amu Darya and their tributaries, and to provide interpretation of results and generalization of obtained data. The Navruz database will be provided by Howard Passell at Sandia National Laboratory (a previous collaborator on the group of projects at ISTC). The Navruz data was obtained on the geochemical condition of the objects of the biosphere by scientists from Kyrgyzstan, Uzbekistan, Kazakhstan and Tajikistan. The generalization of data obtained by scientists from 4 countries will provide a complete picture of the geochemical and ecological state of the Aral Sea basin, starting from headwater to the mouth in the Aral Sea.

Purity of water in rivers is one of the key environmental characteristics. The presence of significant amounts of heavy metals or deficit metals in the waters of the rivers can lead to serious diseases of the population consuming the water. The most dangerous is the dissolved heavy metals. Before water consumption water normally performs of reducing the share of suspensions fractions of the water. At the same time to reduce dissolved metals need the complex physical and chemical cleaning methods, which usually are not available in rural areas. In Central Asia, more than 60% of the population live in rural areas and knowledge of purity of water (quantity heavy metals in the water) are very important.
Amy-Darya and Syr-Darya Rivers are is main rivers of Central Asia. Originating in the mountains of Tajikistan and Kyrgyzstan they are passes through Kyrgyzstan, Uzbekistan, Tajikistan, Turkmenistan and Kazakhstan. Rivers strongly impacts to all social and environmental aspects of the life of the population living in the rivers basin. The Rivers reach to Aral Sea, but due to extensive agriculture and economy development of the Central Asian countries, the volume of water delivered to the Aral Sea reduced by more than an order of magnitude since the 1950s. The shrinking of the Aral Sea has become as a global problem and has led to a large environmental impact.
The water from the two big rivers is used primarily for irrigation, industrial and domestic uses. Mostly the water is used for irrigation. In the 20 century Central Asian countries faced with a demographic explosion: every 30-40 years, the population of these countries has doubled, and this trend is continuing. As a result of population growth the use of new land for agriculture and resettlement of the population is necessary. But the use of outdated technologies and irrigation systems leads to large of water loss and water pollution in the mainstream of the Syr Darya and Amy Darya. At least two factors should be noted relating to the water problem in Central Asian today: 1) growing tension in relations between the neighbor Central Asian Countries in the management of regional water resources; 2) environmental changes caused by global warming, drying up of the Aral Sea, and as a result, the process of desertification.

The database consist of date on a water quality which was evaluated during the express-tests on some physical-chemical parameters such as temperature, salinity, conductivity, dissolved oxygen, pH, eH, turbidity, etc.
An important tool for monitoring of the water quality can become of geochemical study of waters, soils and bottom sediments around rivers. Study on distribution of major and trace elements in soil/bottom sediments samples can provide information on place of silts origin, knowledge of major and trace-elements transition in the system soil-water-bottom sediments and a number of other interesting factors. Geochemical study can also identify land, rivers and reservoirs areas contaminated by heavy metals, inorganic toxins. Such a study becomes particularly urgent; taking into account large number of uranium Mountain-metallurgical enterprises, as well as uranium factories located in the up and middle stream of the Syr-Darya and accumulated more than 100 million tons of uranium production wastes. Research will assess the contribution of large reservoirs (Nurek on the Vakhsh River, Toktogul on the Naryn River and several others) to the purity of water and bottom sediments in the rivers. It is well known that large reservoirs purify waters from the suspensions and some heavy metals.

Analysis of concentration of elements in the beginning of the rivers, along its shores and in its mouth will allow learning character of sedimentation of metals along its shores. Heavy metals will be mainly precipitated in the beginning of rivers. But rivers were in a dynamic regime, seasonally raises and decreases the water line that obviously can lead to mixing and redistribution of bottom sediments. In the course of long accumulation of bottom sediments there could be a gravity separation of minerals. Heavy metals and minerals could appear in the bottom layer; in too time lights minerals could drift on a water traffic route. Process of distribution of elements in soils strongly is influenced by geologic features of locality.
Staff of project has sufficient experience in implementing projects of the International Science and Technology Center (ISTC) T-1000, T-1082 and T-1163. In frame of regional experiment Navruz (Kazakhstan, Kyrgyzstan, Uzbekistan, Tajikistan and the United States) monitored for over 10 years (1999-2009) radiation and ecological condition of the Transboundary Rivers and their main feeders.

Participating Institutions


Sandia National Laboratories / Geosciences and Environment Center