## 1 Introduction  
Bedforms such as ripples and dunes [1] are prevalent sedimentary structures in alluvial river channels. Their development and evolution significantly influence the flood risk, river transport, and infrastructure stability [2, 3, 4]. The kinetic energy of water flow primarily shapes these bedforms, such as dunes [5, 6], and both bed resistance and sediment transport undergo changes during their formation and development [1, 7, 8]. Additionally, bed resistance plays a crucial role in river energy dissipation [9, 10], and it is closely related to sediment transport. Consequently, bedforms, sediment transport, and bed resistance interact in a complex network [11, 12], which complicates the accurate prediction of sediment transport and bed resistance. Thus, research into the characteristics of bedform evolution and their impact on sediment transport is essential to provide technical support for the stable operation of river engineering projects and flood control and siltation reduction practices. Extensive research on river dynamics has focused on the features of bedforms, sediment transport patterns, and the characteristics of bed resistance distribution, yielding significant results. The data for bedforms characterization are primarily obtained through indoor flume experiments and field observations. These data are used to elucidate the mechanisms of interaction between the physical characterization parameters of bedforms(e.g., dune length and height) and hydrodynamic factors (e.g., discharge and velocity). This approach has led to the establishment of empirical relationships between these parameters and the development of bedform size recognition tools [13; 14; 15; 16; 17; 18]. Certain researchers have quantified the distribution patterns of bedforms using statistical analysis of field-measured physical parameters [5; 19]. Bed resistance significantly influences sediment transport. It is worth mentioning that the research results on bed resistance changes caused by changes in bed morphology can be roughly divided into the following categories. The first approach involves the determination of the effective shape roughness height using empirical methods [20]. The second approach is based on numerical simulations that yield empirical formulas for hydraulic roughness of different bedforms with varying lee side angles [21]. Most recently, research has integrated the actual flow patterns and dune geometry influences by applying the principles of momentum and energy balance equations and introduced an empirical bed form drag coefficient to study the contribution of dunes to flow resistance [22]. Additionally, numerical simulations of river bedforms have been conducted based on experimental data [23; 24; 25]. Regarding sediment transport patterns, most existing studies have derived empirical sediment transport formulas from indoor experimental data [26; 27; 28; 29; 30], typically using uniform sand particles. In recent years, numerical simulation methods have been employed to develop sediment transport prediction models [31; 32; 33; 34; 35]. Bed resistance comprises sediment resistance caused by sediment particles and shape resistance caused by dunes. In the presence of dunes on the bed, shape resistance often dominates bed resistance [36; 37; 38; 39]. The development and evolution of dunes directly affect shape resistance, thereby determining the sediment transport capacity. These findings indicate that research has extensively explored the bedform features, the sediment transport patterns, and the bed resistance distribution characteristics, establishing empirical relationships and numerical models related to hydrodynamics and dune bedforms [21; 40; 41; 42; 43; 44]. However, owing to the complexity of changes in bedforms, sediment transport patterns, bed resistance distribution, and their interactions, the practical application of these empirical relationships and models often yields unsatisfactory results [3; 45; 46].