Lecture
This lecture covers the characteristics of bed shapes and flow resistance in rivers, including the influence of background shapes on shear stress and sediment transport. It discusses the apparent roughness of the bed, Shields diagram, geometric features of dunes and wrinkles, and the resistance on a corrugated moving bed. The instructor explains the impact of bed shapes on stress, the relationship between water level and flow, and the influence on rating curves. The lecture also addresses the effects of background shapes and provides practical examples of how these factors affect river hydraulics.