Investigating the Application of Channel Boundary Conditions for Model Calibration and Validation

This study investigated how the stage-type and the flow-type boundary conditions may impact the channel flow solutions in order to address issues concerning adequate channel boundary conditions for model calibration and validation. It is revealed that using the stage-type boundary condition and using the flow-type boundary condition yield the same results as long as the conditions are consistent. Because flow may be more sensitive to the change of system input (e.g., boundary condition, source/sink, model parameter, etc.) than stage (or depth), it is suggested that the more accurate measured stage data be used for calibration with the less accurate measured flow data employed as a secondary check point to ensure correct calibration-validation outcomes. A sensitivity analysis to determine an adequate time-step size for the desired computational mesh is essential for valid model calibration and validation.