Soft Bedrock Erosion Modeling with a Two-Dimensional Depth-Averaged Model
Publication: Journal of Hydraulic Engineering
Volume 137, Issue 8
Abstract
Many rivers in Taiwan have steep slopes, are subject to typhoon-induced flood flows, and contain soft bedrock that is exposed at many locations and easily erodible. The occurrence of extensive bedrock erosion has been a major threat to river infrastructure at many locations. Soft bedrock erosion, therefore, is an important process to consider for river projects in Taiwan. In this study, bedrock erosion models are reviewed. A specific model is proposed by combining two existing models incorporating both the hydraulic and abrasive scour mechanisms. The proposed bedrock erosion model is incorporated into a two-dimensional mobile-bed model, and the integrated model is tested by simulating bedrock erosion downstream of the Chi-Chi weir on the Choshui River in Taiwan. A calibration study is performed to determine appropriate values of the model parameters based on two and a half years of measured data. The model is then assessed based on a verification study that compares model predictions of bedrock erosion of the same reach to two additional years of measured data. The bedrock erosion model is found to be suitable for the river reach studied. Further improvement, however, is still necessary, which points to potential future research.
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Acknowledgments
The writers would like to acknowledge that the Water Resources Agency of Taiwan has sponsored this study. The project Liaison Officer, Director Chen, Hung-Kwai, and the project review committee in Taiwan have provided valuable technical comments. Peer review provided by Jennifer Bountry at the Bureau of Reclamation is greatly appreciated.
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Published In
Journal of Hydraulic Engineering
Volume 137 • Issue 8 • August 2011
Pages: 804 - 814
Copyright
© 2011 American Society of Civil Engineers.
History
Received: Mar 31, 2010
Accepted: Nov 16, 2010
Published online: Nov 19, 2010
Published in print: Aug 1, 2011
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