The Development of Probabilistic Simulations in HEC-RAS Model Sediment Transport

Sensitivity of Longitudinal Cumulative Mass Change of Bed Material to Manning’s Roughness.
Sponsors: U.S. Bureau of Reclamation Upper Colorado Basin
PI/Co-PIs: Dr. Konstantine Georgakakos (HRC) and Dr. Zhengyang Cheng
Collaborators: U.S. Army Corps of Engineers Hydrologic Engineering Center


HRC began a two-year grant in August 2019 collaborating with the U.S. Bureau of Reclamation Upper Colorado Basin (BoR) and the U.S. Army Corps of Engineers Hydrologic Engineering Center (HEC) to develop and implement a methodology and related software for hydraulic and sediment transport simulation with explicit uncertainty characterization of the outputs in conjunction with the Hydrologic Engineering Center-River Analysis System (HEC-RAS). The objectives of the project, which is funded by the BOR, are to systematically explore the uncertainty impact on model results of various inputs and parameters. Statistical analysis will be performed using the results of the developed software and the available flow and sediment measurements for a single reach of the Middle Rio Grande with the purpose of estimating the uncertainty of the simulations. The development strategy is to apply the Monte Carlo method to generate stochastic results by varying sediment transport models, parameters (e.g., roughness and bed gradation) and forcing (e.g., flow and sediment load) in the HEC-RAS simulation environment. This uncertainty analysis and simulation effort is identified as an important and valuable effort in both research and application.