“Improving the Computation of Large Wood and Other Geomorphic Parameters in Rivers”

Description

Background: Locally-available wood offers attractive environmental benefits when used in bank stabilization. However, engineers in much of the country are uneasy using wood in bank protection designs due to lack of standard design tools based on scientifically sound information. The Engineering With Nature program has funded the development of a software update in the USACE river analysis software HEC-RAS to facilitate design and analysis of large wood in rivers. This update will plug into existing work flows and utilize familiar software for bank stabilization design and will greatly facilitate the consideration of natural wood by many more river engineers. Major Tasks Are To: (1) Identify data gaps of using large wood design for rivers and provide potential methods for addressing gaps. The CESU non-federal partner will be tasked with reaching out to appropriate agency, university, and private experts. Part of this task will be to host a 1-day interagency meeting with invited experts. The venue itself will be provided by USACE or a partner agency free of charge. It is expected that information on state of the knowledge will be presented as launching points for discussion.(2) Using information gathered from Task 1, research how to calculate driving and resisting forces on large wood in rivers. Information on best materials and practices shall be reported as well as environmental variables that impact the use of large wood in rivers. A large part of this task will be to code stand alone software to be integrated into the USACE HEC-RAS software. Requirements of the software is that it must read from the 1D hydraulic model output files in order to compute driving forces, resisting forces, and factors of safety. The software application must provide simple visualizations in cross section and plan view. It must also read from tables of wood properties which will be provided by USACE. Data will flow one way, from HEC-RAS to the application. It is not required to write information back to RAS or include options within existing tools or displays. it is to be written using WinUI, utilizing Xamel islands in WinUI to use CSIchart. Close coordination with the USACE Hydrologic Engineering Center is required, and prior experience reading HEC-RAS output is strongly desired, so the final tool can be seamlessly incorporated into RAS. In addition, the successful Recipient is to document ways the tool could be enhanced in the future for use with RAS2D.a. Note: USACE will select the equations to be coded based on feedback at the interagency meeting described above and will provide worked-out spreadsheet examples. The Recipient is not responsible to make the selection.(3) Provide a literature review and short scoping document on ways to automate high-level geomorphic assessments sufficient for deriving channel velocity and bank height. Previous experience automatically computing geomorphic values over large regions is strongly desired.(4) (Option for outyears) Develop and maintain an online platform to facilitate landowners in applying new bank stabilization methods, locating headcut locations within large watersheds, and generating stream centerlines and other enhancements to enable cross section analysis. Public Benefit: HEC-RAS is the most commonly used river analysis and design software in the world—standalone software applications added to HEC-RAS find quick adoption and use by the Public. The wood calculator will allow engineers to compute force and moment balances and factors of safety. By facilitating these computations, engineers will be more able to determine when additional anchoring is needed or when such features should not be implemented at all due to excessive hydraulic forces. This will increase the reliability and robustness of large wood designs, which should both reduce project failures and make engineers more comfortable to include wood features in bank stabilization and other projects.

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