Dettmar characterizes the wave family created during surge flushing into so-called bed load and suspension waves [Dettm2005a].

• Bed load waves are surge waves creating high wall shear stresses. Thus, these waves are able to mobilize coarse-particle and cohesive deposits and transport them as bed load and suspensions.

• Suspension waves show less wall shear stresses. Therefore, they can only mobilize and transport fine-grained and suspended deposits. In any case, the wall shear stress τ₀ of the surge wave must reach or rather exceed the critical erosion shear stress τ_e,crit as the starting point for the mobilization of sedimented solids.