Understanding how river bank side slopes and sediment size control failure thresholds in steep streams - Year two
Northwest Hydraulic Consultants Ltd. (NHC) is often involved in the restoration and design of steep streams. To date when assessing these river channels, NHC has relied upon experimental results conducted with fixed vertical river banks and a series of assumptions have been used to figure out how to make river channels with sloped banks. These assumptions introduce risk into the design process and likely result in the rock used to make the channel banks being over-sized. We plan to address this issue through a combination of physical experiments and field data collection. In this project we will (a) run experiments in the UBC laboratory facilities under different channel geometries (such as channel width and bank angle) and particle size conditions, (b) inform and validate experiments with field data collected in British Columbia and (c) update the design tools used by NHC to design steep channels. As part of this research project the water velocity, water depth, river bank angles, and range in sediment size will be evaluated. The project will increase our knowledge on the factors that influence stability of mountain streams and produce a quantitative design tool readily available for fluvial geomorphologists.