From discrete to continuum description of weakly inertial bedload transport

Granular bedload plays a crucial role in shaping streams and influencing their development over time. This process involves the movement of grains along the stream bed surface driven by the shear stress from the flowing water. For an accurate model on a practical scale, it is essential to grasp the key properties of the granular layer interacting with the water. Our focus lies in understanding the rheological characteristics of the water grain mixture when grain movement is localized within a thin layer near the bed surface and under a weakly inertial regime. This aims to expand our understanding of viscous-laminar properties mostly described for a thick shear layer in the literature.