The structure of the Karay river basin by the longitudinal slopes of the river beds and the average gradients of water catchments slopesMikhail Bukovskiy, Kirill Kuzmin, Maria Chernova and Elena VishniakovaE3S Web Conf., 163 (2020) 06002DOI: https://doi.org/10.1051/e3sconf/202016306002