Impacts of Ship Waves on Bed Morphology of a Trapezoidal Cross-Sectional Channel

Abstract

Ship waves could alter the hydrodynamic field and play an important role for sediment movement and morphological changes, especially in shallow water regions of inland waterways. However, the response of riverbed morphology to ship waves is still unclear. In this paper, the impacts of ship waves on the bed profile in inland waterways are investigated by means of laboratory experiments. Observations of ship waves and bed profile changes exposed to different ship wave conditions are conducted. There exists a power exponential relationship between the corresponding polygon area and perimeter of the cross-sectional bed profile after the action of ship waves, which indicates that the bed profile is only adjusted in the geometric direction. Moreover, the dimensionless local scour depth is well predicted through the dimensionless expression of ship-induced near-bed velocity, ship draft, and offshore distance, which describes the impacts of ship waves on the bed morphology in inland waterways.