Flow Sediment Transport and Morphological Evolution of Lateral Separation Eddies in the Grand Canyon

Project: Research project

Project Details

Description

Flow Sediment Transport and Morphological Evolution of Lateral Separation Eddies in the Grand Canyon Flow, Sediment Transport, and Morphological Evolution of Lateral Separation Eddies in the Grand Canyon Glen Canyon Dam operations under the current Record of Decision (ROD) restrict the rate of discharge increases and decreases, and one of the reasons for these restrictions is to limit sandbar erosion. While failure of steep beaches during a rapid downramp is likely, the rate of sediment mass loss for moderately-sloped beaches under differing dam operation scenarios remains largely unknown. This question is critical to minimizing the mass loss during daily fluctuating flows and following high flows. Previous research has resulted in the creation of a computer model to predict the stability of beach faces under differing dam operation scenarios. Validation of the stability model and incorporation of the stability model into a morphological eddy sandbar model is critical for predictive application to Grand Canyon sand bars. Flow, Sediment Transport, and Morphological Evolution of Lateral Separation Eddies in the Grand Canyon - 2012 There have been three high-flow experiments (HFEs) in Grand and Marble Canyons. A chief aim of these experiments was to explore the feasibility of using such flows to restore sandbars within recirculation eddies downstream of channel constrictions in the Colorado River. The general timeaveraged, recirculation flow structure of these recirculation eddies has been modeled using timeaveraged two- and three-dimensional numerical models. However, these models have failed to predict many of the detailed flow features found in field data and descriptions. Further, previous eddy sediment transport models have generally over-predicted the rate of deposition when there are substantial suspended sediment concentrations supplied to the eddy and under-prediction of erosion when mainstem sediment concentrations are low. As a result, prediction of the eddy sandbar building phase during an HFE cannot be predicted very well and the erosion of sandbars during low periods of low sediment concentration is very poor.
StatusFinished
Effective start/end date8/2/112/25/16

Funding

  • DOI: US Geological Survey (USGS): $97,291.00

Fingerprint

Explore the research topics touched on by this project. These labels are generated based on the underlying awards/grants. Together they form a unique fingerprint.