Formation of the Ion Composition of the Barguzin River Waters (Lake Baikal Basin) under the Conditions of Saline Landscapes

The results of measuring the ion composition of the Barguzin River waters during periods of different water contents and assessments of hydrological factors of water flow self-purification are presented. For the first time, it is shown that realization of the self-purification potential of the river increasing with water discharge raise is limited by the entrance of mineral matter from salt lakes and saline lands of the lacustrine–alluvial plain, which occupies a considerable part of the Barguzin Depression situated in middle part of the river current. The expansion of saline landscapes in the depression is due to its rift origin, seismic activity, abundant outcome of underground waters, and arid climate. The supporting influence of the Shamanskii rift near the village of Barguzin results in large-scale depression waterflooding during a high water content and in intensive salts washing out of its territory. Particular environmental conditions in the river basin determine as well the peculiarities of formation of the ion composition of the Barguzin River waters differing from classic viewpoints concerning the decrease in river mineralization upon an increase in their outflow.