Influence of channel naturalization on hydraulic regime

Abstract

Uncontrolled naturalization of a trained river leads to an increase of its bed surface roughness, transformation of its cross-section and longitudinal profile. Influence of bed roughness and its profile curvature of conveyance was investigated in four hydraulic distorted-scale models of a trained river. Hydraulic resistance to water flow of a rough and smooth, straight and curved river bed was compared in this investigation. The influence of Reynolds and Froude numbers on the roughness coefficient and the minor-loss coefficient of a trained river and its meander was also investigated. It is determined that a slight curvature of a trained river bed is acceptable and even desirable. To avoid long-lasting meandering of a trained river, control of the naturalization process must be carried out.