Hydrochemical and hydrobiological investigations of the Upper Angara R. and of its tributaries

We have presented the results of hydrochemical and hydrobiological investigations performed in the Upper Angara R. basin and at North Baikal tributaries. A 4-fold increase of mineralization in the Upper Angara R. water from sources to inflow was found out due to income of tributaries waters with a high mineralization. Compared to previous investigations, we registered enrichment of waters in the investigated water flows with trace elements. Increase of normative by copper, molybdenum, iron and manganese was registered in water of some rivers. Determination of microorganisms sanitary groups showed a trend to improvement of riverine waters quality.