Journal of Water Resource and Protection, 2013, 5, 17-26 doi:10.4236/jwarp.2013.51003 Published Online January 2013 (http://www.scirp.org/journal/jwarp) Assessment of Water Quality of the Trans-Boundary Zarafshan River in the Territory of Uzbekistan Rashid Kulmatov 1 , Christian Opp 2 , Michael Groll 2 , Dilafruz Kulmatova 1 1 Department of Applied Ecology, National University of Uzbekistan, Tashkent, Uzbekistan 2 Department of Geography, Philipps-Universität Marburg, Marburg, Germany Email: rashidkulmatov@yahoo.com Received October 30, 2012, revised November 29, 2012; accepted December 7, 2012 ABSTRACT The Zarafshan river is a main trans-boundary river of the Aral Sea basin. As the main water resource, the Zarafshan river water is mainly used by the republics of Tajikistan and Uzbekistan. We explored the trends of space-time pollution of river water with ammonium, nitrates, phosphates, biological oxygen demand (ȼОD), fluorine and some heavy metals at seven water sampling points along the Zarafshan River in Uzbekistan. The experimental data showed that the water quality of the Zarafshan river in 2002-2009 has undergone a considerable transformation, even by the length of the river. The chemical composition of the Zarafshan river water underwent changes due to the agricultural collector-drainage discharges and the sewage of the cities of Samarkand and Navoi. The water pollutants of the Zarafshan river, as a con- sequence of the agricultural pollution, consisted of mineralization, ammonium, nitrate, phosphate, and pesticides. Therefore, it is necessary to monitor the chemical composition of the large agricultural collector-drainage discharges into the river. The main sources of the heavy metals (primarily arsenic and zinc) in the Zarafshan river water were probably ore processing manufactures located in territory of Tajikistan. Keywords: Trans-Boundary River; Zarafshan River; Water Pollution; Water Discharge; Collector-Drainage Discharge; Sewage 1. Introduction The origin of the Zarafshan river (contained within the topographical realm of the Amudarya basin) commences in Tajikistan. Also, a considerable part of this river basin is found in the Republic of Uzbekistan. The head waters of the Zarafshan river begin in Tajikistan at the Zeravshansky glacier. This glacier is located specifically in a mountain knot of Mt. Cokcy wherein there is a joint of the Turke- stansky and Zeravshansky ridges. This occurs at an ele- vation of 2800 meters above sea level. The length of the Zarafshan river is 781 km; the drainage basin area is 143,000 km 2 . The average long-term water flow discharge amounts to 190 m 3 /sec, with the average long-term dis- charge of the river water being 5.103 km 3 [1,2]. The Zarafshan river is a representative of the rivers hav- ing a glacier-snow feed. The increase of water discharge begins in April and increases generally each month until July, when it passes its high water (flood) period. The recession of the discharge river flow commences in Au- gust and continues until February-March, when it reaches its minimum discharge point [1,2]. The irrigated lands of the Zarfshan river basin within the Republic of Uzbekistan, which is part of the adminis- trative division located in provinces of Samarkand and Navoi. The lower part of the Zarafshan river basin is fed by waters from the Amudarya through the Amu-Bukhara irrigation canal [2]. Published works by Kulmatov and Hoshimhodjaev [3] and Toderich [4] deal with investiga- tions conducted concerning the qualities and quantities of the Zarafshan river water. The qualities of the river water for the short period dealt with the contents of heavy metals and others pollutants have been also investigated. The economic situation and the prospects for the devel- opment of the economy of the Zarafshan river basin have also been analyzed [2,5]. The distributions of diseases along the Zarafshan river basin have been studied by using GIS technologies [6,7]. Olsson et al. [8] studied the long-term changes of the Zarafshan river discharge by using hydrological models. However, published works that are available have not included any studies dealing with the long-term trends of space-time distributions of some pollutants of the Zarafshan river. Previously, we have studied the space-time changes of the general mineralization, concentrations of nitrites, phe- nol, mineral oil and copper at four water sampling points along the Zarafshan river [5]. In this study, we continue our investigation on the space-time of changing trends of concentrations of ammonium, nitrates, phosphates, ȼОD, Copyright © 2013 SciRes. JWARP