TY CONF TI MONITORING OF THE QUALITY OF SURFACE WATERS OF THE USMAN RIVER WITHIN THE VORONEZH STATE NATURAL BIOSPHERE RESERVE KW maximum permissible concentration KW water pollution index KW measurement KW pollutant KW surface water JO Reproduction, monitoring and protection of natural, natural-anthropogenic and anthropogenic landscapes AU Kudaeva, K.A. AU Yablonskih, L.A. AU Butsik, A.A. PY 2022 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov