Experimental Study of Bedform Development Characteristics and Their Effects on Sediment Transport

Bedforms are complex and varied features on riverbeds created by the interaction between flow and sediment particles. Bedform evolution is crucial for understanding sediment transport, bed resistance, and the ecological environment of rivers. In this study, a series of movable-bed dune experiments were conducted utilizing advanced 3D topographic laser scanning technology to precisely measure the 2D and 3D dune bedforms under various conditions. This enabled the detailed analysis of the bedform parameters, including the dune length and height, the crest height, and the trough depth. Furthermore, this study examined the relationship between bed resistance and dune morphology and investigated how the intensity of bedload transport affects bed resistance. The findings indicate that bedload mass transport on the riverbed significantly contributes to increased bed resistance. Given the limitations of the traditional bedload transport rate formulas for dune bedforms, this research introduces a new formula derived from the experimental data. The accuracy of this formula was confirmed using the nonlinear least squares method. Our study enhances the accuracy of sediment transport predictions and provides scientific support for river management and engineering practices.