Abstract
River bathymetry is an important parameter for hydrodynamic modeling;
however, it is associated with large bias because direct large-scale
measurements are impractical. Recent studies adjusted river bathymetry
data based on assessment of the difference between modeled and observed
water surface elevation (WSE); however, river discharge model
uncertainties can lead to unintended errors in the correction. In this
study, we propose a simple but robust correction method using the WSE
bias, based on stage–discharge rating curves rather than time series
data. The rating curve represents only the characteristics of the river
section, and is not sensitive to instantaneous errors. Our results
showed that the “corrected river bathymetry” converged among discharge
experiments driven by noise-corrupted runoff forcing. Given the
difficulty of eliminating discharge errors, a method for correcting
river bathymetry that is free from discharge errors is important for
improving hydrodynamic modeling.