Ecological and geochemical state of Lake Utichye-3 and its surroundings(Republic of Khakassia)

Lake Utichye-3 is located in 23 km to the east of the resort ''Lake Shira''. Thewater surface area is 1.41 km2, the maximum depth - 5.5 m, the absolute mark of water - 362.1 m. The lake is internal-drainage. Themineralization of the lake water is 9.9 g/dm3. The reaction of the aquatic environment is slightly alkaline: pH = 7.6. The lake water ischloride-sulphate, magnesium-sodium according to the fixed-term ionic-salt composition. The concentration of pollutants and currenttoxiccomponents (nitrates, nitrites, lead, cadmium, mercury) do not exceed the rated values for the surface water. The curative mud isthe main treasure of Lake Utichye-3. It is used in the resort ''Lake Shira''. Modern silt sediments of the lake are distributed quite evenlyon the bottom of the lake basin, with the increasing volume of mud deposits to the center of the pool. According to main physicalchemicalindicators they correspond to the middle-sulphide silt curative mud with low mineralization. Environments of the lake are thetypical agrolandscapes. There are widely developed agricultural lands - ploughlands, pastures, hay fields, bushes, and forests.Agrolandscape areas do not practically influence the lake waters and bottom sediments because of the limited grazing on the local areas.The southern chernozems dominate in the area of the lake, the heights are occupied by incompletely developed soils. In the low areasthe southern chernozem comes in complex with the ordinary chernozem. Both have a mild and moderate degree of salinization. Salinesoils fringe the lake by narrow strips and are presented by saline lands, a complex of marshes with chernozem-meadow and meadowsoils. The latter are characterized by a strong degree of salinization and a chloride-sulphate profile. The comparison of baseline valueswith soil clarkes by A.P. Vinogradov shows that the significant enrichment of the following elements: Ba (clarke concentration - 1.4);Sr (1.5); V (1.8); Co (1.4); Li (1.1), Cu (1.2); Pb (1.1), Sc (1.3), is typical for the local geochemical specialization. Such elements as Mn,Ti, Ni, Zr, BA, Zn, Be, Sn, Ag, Th are characterized by low content (clarkes concentrations are within the range of 0.4 to 0.8). The valueof the total contamination indicator is insignificant (from 2.1 to 7.6), which shows the minimum degree of the soil pollution; this figurerises from 8.3 to 10.5 only for five samples, which corresponds to the low degree of contamination. In our opinion, the elevated valuesof Sr, V, Ba can be attributed to the presence of natural geochemical anomalies, especially as these elements are the most significant forthe region; increased values of Cu, Pb are characteristic for carbonate rocks of the Mansko-Batenevsky metallogenic zone. The value ofthe summary pollution indicator corresponds to the quite favorable environmental state of geological environment according to theexisting regulations.

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