Restoration of Gravel Bed Rivers via the Use of Stone Clasts (Rocks)

Different studies have examined the transport of fine sediments over and within gravel beds. Comparatively little attention has been given on how distinguishable isolated roughness elements, such as clasts (rocks or boulders), may affect the movement of sand over and within gravel substrates. Rocks have been widely used for stream restoration purposes. Previous research focused primarily on the effects that rocks have on the flow structures in their vicinity neglecting possible effects on sediment depositional patterns. The overarching objective of this study is to examine experimentally the twofold effect of the presence of clasts on the movement of sand over and within a gravel bed. Specifically, this study will provide: 1) an improved understanding of the linkage between the mean flow characteristics and the sediment depositional patterns; 2) an analysis on the frictional characteristics around the clasts; and 3) a quantitative description of the sediment deposition within the substrate as it relates to fish survival.