Integrating channel design and assessment methods based on sediment transport capacity in gravel bed streams

Abstract

Stable channel design has historically dominated the fields of hydraulic engineering and fluvial geomorphology, guiding practitioners and policy makers alike, and underpinning stream interventions from roadway crossings (Lagasse et al., 2012;Richardson et al., 2001) to restoration efforts (e.g., Johnson et al., 2020;Shields et al., 2003). Here, we define a geomorphologically stable river as "one that has adjusted its width, depth, and slope such that there is no significant aggradation or degradation of the stream bed or significant planform changes (meandering to braided, etc.)

Post-wildfire sediment source and transport modeling, empirical observations, and applied mitigation: an Arizona USA case study

“…Sediment transport estimates are used to look at how supplied sediment can transport through the channel 140 system. Sediment transport modeling used the FLOWSED/POWERSED platform in the RiverMorph software and provided estimates of average annual sediment transport through a specific cross section of channel given an annual flow scenario (Rosgen 2009;Hall and Bledsoe 2023). Estimates of sediment supply into a reach can be compared within the reach to aggradation or degradation for both existing and proposed design.…”

“…Estimates of sediment supply into a reach can be compared within the reach to aggradation or degradation for both existing and proposed design. This analysis is sensitive to several data inputs including annual flow duration curves 145 (based on watershed size), bankfull discharge, suspended sediment and bedload sediment rating curves, channel configuration and slope (Rosgen 2006;Hall and Bledsoe 2023). These data are difficult to obtain for ungauged ephemeral systems; we used sediment rating curves and dimensionless flow duration curves developed during the 2010 Schultz Fire sediment analysis which were derived from regional data and research from the Beaver Creek Research watershed effort (Natural Channel Design 2012).…”

Spatiotemporal Variability of Channel Roughness and its Substantial Impacts on Flood Modeling Errors

“…In erosion control and fluvial geomorphology, n is an important control for bank and soil erosion (Langendoen & Simon, 2008). In infrastructural engineering design, n influences the estimation of flow depth (Arcement, 1989) and thus the design criteria of, for example, bridges and culverts (Richardson & Davis, 2001;Yaryan Hall & Bledsoe, 2023). In aquatic ecosystem management, Manning's n is used to design plans for river restoration (Clilverd et al, 2016) and model suitable fish habitat (Fitz et al, 1996;Gillenwater et al, 2006).…”