Submitted to: Gravel-Bed Rivers in the Environment
Publication Type: Proceedings
Publication Acceptance Date: April 1, 1997
Publication Date: N/A
Technical Abstract: Controlling the grade of a channel with structures has been an effective means of erosion control applied to streams. Although, the effectiveness of grade control structures is not readily apparent until long after installation. Results are presented in this study on the influences grade control structures have on flow and channel cross- sections. Measurements of a reach between flumes, which act as low-drop grade control structures, within Goodwin Creek Watershed in northern Mississippi and instrumented by USDA's National Sedimentation Laboratory, was used to demonstrate the long term effects of structures on the channel. From periodic surveys over eleven years from installation of the structures, results show bed slope decreased by 30 % with channel banks remaining relatively stable in areas of channel degradation and some bank erosion or failure along aggradational areas. Model simulations were performed to replicate the response of structures to flow from the watershed system. Simulation results indicated smaller events propagate effects of structures farther along the channel than larger events. Thus, many smaller events may have a large impact on the channel when comparing the channel with and without structures. This information is important in understanding and designing a system of structures to control erosion within a watershed.