MORPHOLOGICAL EVOLUTION OF STEEP-SLOPED RIVER BEDS IN THE PRESENCE OF A HYDRAULIC JUMP: EXPERIMENTAL STUDY

摘要

The present work focuses on an experimental approach to morphological evolution of steep-sloped channels under overloading condition and in the presence of a hydraulic jump. Laboratory experiments and two measuring methods - a probe and a digital imaging system -allows us to identify two stages of the bed deformation under such hydrodynamic and sedimentoligicai conditions: (1) hydraulic jump stabilisation and subsequent sediment front formation, and (2) development of the sediment bore and progressive vanishing of the hydraulic jump, the transition of flow regime being taken over by the bed profile. Measurements compare favourably with theoretical profiles and with qualitative considerations of previous investigators.