2015 Volume 25 Issue 3 Pages 217-220
Field and laboratory studies of transboundary rivers in Uzbekistan were carried out in the fall of 2013 and the spring of 2014. The rivers were classified as rivers, small rivers, and streams. Carbon hydrogen sulfate, calcium, and magnesium were found to be the major ions in each of the rivers. The chloride and sodium concentrations were higher in the middle and lower reaches of the large rivers than in the other rivers and in the upper reaches of the large rivers. The trace element concentrations found in the water samples from the transboundary rivers were compared with the maximum allowable concentrations at the regional level. The strontium concentrations were higher in the water samples from the large rivers in drained areas than in the water samples from the other rivers. Increased content antimony, molybdenum, arsenic, and lead were detected in the rivers with low flow rates. These metals were detected in the rivers because there are ore mining and processing enterprises that cause the release of antimony, lead, zinc, and uranium in the part of the study region that the upstream parts of the rivers pass through.
