Sensitivity of Field Data Estimates in One-Dimensional Hydraulic Modeling of Channels

Abstract

A hydraulic simulation study was carried out for Red Hill Creek, an urban stream channel in Ontario, Canada. Over one million simulations were conducted using the HEC-RAS4b model to evaluate the sensitivity of model predictions to field data accuracy, density and estimation techniques and provide guidance toward balancing human resource allocation with model accuracy. Increased cross-sectional discretization and improved estimates of floodplain roughness dominate the accuracy of the results of computed water surface elevations. For a range of field hours available for data collection, a sampling strategy focused on maximizing the number of sparsely detailed cross sections is shown to outperform a sampling strategy using the same number of field hours to sample fewer cross sections with a higher resolution.