Unsteady overland sedimentation

摘要: Abstract Sediment flux to fluid flow in a rill is represented with physically based models for simultaneous sediment entrainment (detachment), deposition (settlement) and lateral inflow, shown be an improvement over existing concepts describing low concentrations. Unsteady sedimentation overland rills are then described by continuity equations approximations flow, transport capacity. The reduced, assumed pattern on plot, one-dimensional of motion which do not utilize sheet approximations. method characteristics' solution these uniform rainfall excess yields both the hydrograph (rising limb crest) three-part concentration graph, predicted time lag between peaks graphs. resulting model allows substitution reasonable parameter values as opposed requirements conventional given steady-uniform capacity only when (no inflow) infinite channel length (or recirculating flume) or equal inflow concentration. It appears that topographies develop point where latter condition satisfied. Boundary conditions first derivative suggest constraints form entrainment, agree well empirical evidence. General observations made outline expected nature sedimentation.