Numerical simulation of channel pattern changes Part II: Application in a conceptual channel

This paper presents simulated channel patterns for various scenarios in a conceptual alluvial valley by an improved two-dimensional (2-D) mathematical model described in the companion paper. Starting from the same initial channel, different channel patterns have been simulated over a real time period of 250 days for varied boundary and initial conditions, including the inlet water discharge and sediment load, initial valley slope, and erodibility of river banks. Impacts of these control factors are discussed, in terms of the longitudinal bottom profiles of simulated fluvial channels, the geometry of channel cross sections, and the water surface profiles in the conceptual river valley. Results suggest that the upper and lower parts of the same channel may have different planforms because the sediment transport conditions of the two parts differ greatly. Simulated causal relationship between control variables and channel patterns agrees qualitatively with known channel pattern theories.