Annual and decadal net morphological displacement of a small gravel‐bed channel

Abstract

The sediment supplied to a stream channel impacts the morphological trends experienced by that channel, and the long-term trends are important to understand for many riverine applications. We introduce the term 'net morphological displacement' (NMD) to denote the net channel change revealed by the morphological method over multiple sediment transport events to make the concept more explicit for river management and use it to determine equilibrium or disequilibrium states. This study

Evaluating the Effect of Morphologic Units on Fractional Sediment Mobility and Bedload Transport in a Small Pool‐Riffle Reach

“…Mobilizing flows in East Creek are defined as events where discharge exceeds a critical value of Q c = 0.5 m 3 s 1 (±10%). This value represents the flow at which sediment mobility begins for the median grain size of the subsurface sediment and estimated from field measurements and sediment transport rates derived from sediment trap data (Cienciala & Hassan, 2013;Papangelakis & Hassan, 2016;Wlodarczyk et al, 2023). Between 2010 and Water Resources Research 10.1029/2024WR037348 2013, the mean daily flow was 0.06 m 3 s 1 .…”

“…The mean error in DoD was calculated considering three sources of error (Anderson, 2019): (a) Uncorrelated random error from the DEMs calculated using the standard deviation of the residuals, or differences between the actual and predicted elevations, (b) spatially correlated random error from the influence of adjacent grid cells, and (c) systematic error from the survey instrument. The estimated mean error in the DoDs ranged between 0.0036 and 0.0038 m. More information on DEMs and DoDs, including in-depth discussion of uncertainty, can be found in Wlodarczyk et al (2023).…”

“…The main objectives of this study are to: (a) analyze variations in the mobility stage of individual grain sizes across different geomorphic units (riffle, pool, bar), and (b) assess the influence of morphologic units on the spatial distribution of bedload transport under varying flow conditions. Though many authors have studied sediment transport processes and bed stability in East Creek (Cienciala & Hassan, 2013;Hassan et al, 2021Hassan et al, , 2022bHassan et al, , 2022cMcDowell et al, 2021;McDowell & Hassan, 2020;Papangelakis & Hassan, 2016;Wlodarczyk et al, 2023), this study is the first to use a sediment transport model that accounts for spatial variations in fractional sediment mobility.…”

Influence of Sediment Supply Timing on Bedload Transport and Bed Surface Texture During a Single Experimental Hydrograph in Gravel Bed Rivers

“…Experiments were conducted in the Mountain Channel Hydraulic Experimental Laboratory at the University of British Columbia in a 18 m long, 1 m wide, and 1 m deep tilting flume (Figure 2a). Our flume experiments were guided by field measurements conducted at East Creek, a small gravel‐bed stream near Vancouver, British Columbia (Papangelakis & Hassan, 2016; Wlodarczyk et al., 2023). The initial bed slope was 0.022 m/m which is similar to the rapid reach of East Creek (Cienciala & Hassan, 2013; Papangelakis & Hassan, 2016).…”

“…The lowest flow (62 l/s) was chosen to mobilize most of the grain sizes in the flume. Depending on the flood magnitude and the climate conditions, the durations of competent events in East Creek can range from hours to up to more than a day (see Table 2 in Wlodarczyk et al., 2023). For simplicity we maintained the same flow duration for all discharges.…”