ON METHODS FOR DETERMINING THE ROUGHNESS COEFFICIENT OF CHANNELS ALONG THE PERIMETER

The scientific article deals with the issues of uniform movement of the riverbed and the determination of the roughness coefficient of the riverbed (roughness coefficient). The analysis of existing methods for calculating the difference in the roughness coefficients of channels along the perimeter, methods for determining the roughness coefficient of the slopes of channels consisting of two or three parts along the perimeter, well–known scientists - P.N.Belokon, G.K.Lotter, N.N.Pavlovsky are given.There are a some varieties of calculation methods assigned for hydraulic calculations of water flow along the perimeter of a soil channel in the field of hydraulic engineering. A number of researchers states that the roughness of the channel bed imitates the motion of the flow in diverse channels with the movement of the flow under the ice layer. Nevertheless, it should be taken into account that the roughness of the channel bed has its own characteristic (specific) features of the movement of water in different open channels and below the ice cover. The common formulas proposed by number of authors for channels with different roughness along the perimeter cannot be used directly in hydraulic calculations of the flow under the ice cover, and vice versa, the equations of motion of water flow beneath the ice cover are not applied even for channels with various roughness along the perimeter. Therefore, the corresponding choice of methods for determining the roughness coefficients of the canal flow along the perimeter will be the key point to its long-term functioning.