|Shields Jr, Fletcher|
Submitted to: Congress of International Association for Hydraulic Research Proceedings
Publication Type: Proceedings
Publication Acceptance Date: February 18, 1997
Publication Date: N/A
Interpretive Summary: Stabilization of streams with unstable banks is important for preserving agricultural lands that border stream channels. Many unstable stream channels also have degraded aquatic habitats. A study in a laboratory model of a stream channel was conducted to optimize the design of bank protection measures (spur dikes) for aquatic habitats. The volume of the scour hole associated with model spur dikes was used as an indicator of the amount of habitat that could be enhanced by a spur dike. It was found that doubling the length of the spur dike caused the volume of the scour hole to approximately triple. The goal of watershed managers should be to select spur geometry which stabilizes the bank of the stream and provides the largest scour volume subject to cost constraints.
Technical Abstract: Volumes of the scour hole in the vicinity of model spur dikes were measured in a laboratory flume under clear-water flows which overtopped the dike. Contraction ratio, shear velocity, and flow depth were varied in the experiments and found to be positively correlated with the volume of the scour hole. These results will be useful for improving spur dike designs to enhance aquatic habitats and maintain protection of the stream bank.