Response of engineered channels to changes in upstream controls: Simplified 1D numerical simulations

Engineered alluvial channels are dynamic systems and continuously adjust their bed slope (by aggradation and degradation) and bed surface texture in response to changes in the upstream controls i.e., the water discharge, the rate and calibre of the sediment supply (Mackin 1948, Blom et al. 2016, 2017a). These adjustment processes (the transient phase) proceed until a new equilibrium state is reached. The equilibrium state can be disturbed, for instance, by natural changes or measures such as river training, repeated sediment extraction and nourishment measures. The resulting changes in sediment transport capacity, sediment supply rate or caliber of load induces adjustment of equilibrium.