Metal Composition of Surface Waters of the Southern Baikal Region and the Connection with Landscape and Geological Conditions

Abstract

The metal composition of water and bottom sediments of southern Lake Baikal tributaries was studied and the water migration coefficients for micro- and trace elements were calculated. The map showing the study area divided into zones according to their ability to provide the certain water quality was drawn. The significant differences in mineralization, macro- and trace element composition between Lake Baikal water and tributary waters were found out. It was shown that values of water migration coefficients calculated for macro elements are similar in southern and main tributaries whereas coefficient values calculated for trace elements are quite different. This is due to dissolved matter sources such as rocks and deep ground waters which chemical composition is not typical for landscapes of Lake Baikal basin. The contribution of southern tributaries to macro element composition of lake water is between 7 and 15%, whereas tributaries contribution to trace element composition can hardly be evaluated because of higher element concentrations in riverine waters. The lower trace element concentrations in lake water with respect to riverine one is due to trace element migration in the form of complex organic compounds: long water residence time in lake favors to organic compounds decay by means of microbial- and photo-degradation followed by metal precipitation.