Equal-mobility bed load transport in a small, step-pool channel in the Ouachita Mountains

The role of morphology on the displacement of particles in a step–pool river system

“…The results confirm those of Blizard and Wohl (1998) who have concluded that EMT most adequately describe sand and gravel transport in East St. Louis Ck, a step-pool system. It also matches those obtained in Toots Ck (Arkansas, USA) a typical step-pool channel where EMT, measured by linking grain size and hydraulic measurements, was found to be more evident than SST during near-bankfull flow events (Marion and Weirich, 2003). The significance of the results in Spruce Ck must be interpreted with caution.…”

“…In their recently published review of empirical research on step-pool channels, Chin and Wohl (2005) pointed out some of the common observations on bedload transport in these systems: transported sediment is derived from localized sites on adjacent hillslopes and in the channel; bedload entrainment and transport are spatially and temporally discontinuous (Ergenzinger and Schmidt, 1990); sediment are preferentially stored in and mobilized from pools (Schmidt and Ergenzinger, 1992;Marion and Weirich, 1999); bedload transport during lower flows tends to be characterized by equal-mobility transport (Blizard and Wohl, 1998;Marion and Weirich, 2003) where larger grains are as easily entrained as smaller ones because they are more exposed to lift and drag forces (Parker et al, 1982). In spite of these findings, there is still a paucity of field data on the displacement of clasts in step-pool channels.…”

Field based analysis of sediment entrainment in two high gradient streams located in Alpine and Andine environments

“…The best-fit equations (see Table 2) for Rio Cordon (dashed line) and Tres Arroyos (continuous line) are also plotted. morphology (b = − 0.74, Ashworth and Ferguson, 1989;b = − 0.68, Carling, 1983), as well as that reported by Marion and Weirich (2003; b = − 0.73) who studied sediment transport in a step-pool stream (Toots Creek, Ouachita Mountains, USA). The obtained exponent from the Tres Arroyos data series is − 0.787 ( p b 0.001; standard error = 0.014), whereas the one extracted from the Rio Cordon data is −0.639 ( p b 0.001; standard error= 0.023).…”

Assessing potential abiotic and biotic complications of crayfish-induced gravel transport in experimental streams

“…For running waters, predictions of the transport of solids are difficult (e.g., Buffington and Montgomery, 1997;Martin, 2003;Rathburn and Wohl, 2003); and a steadily increasing number of physical processes complicating such predictions have been discovered in the recent past (e.g., Billi et al, 1992;Lisle, 1995;Church et al, 1998;Wilcock, 1998;Marion and Weirich, 2003;Pyrce and Ashmore, 2003). Thus, adding biogeomorphic factors to this already complicated physical framework makes sense only if stream organisms indeed play an important role in geomorphic processes.…”

“…First estimates in this synthesis illustrate that stream animals may modify the discharge required to mobilize gravel and/or sand at a given moment (period of activity) and a given location (used habitat type) by factors ranging from~0.1 to 9. When discharge is assessed in a purely physical context, discharge differences of almost two orders of magnitude can have significant effects on the bed load transport in streams and rivers (e.g., Marion and Weirich, 2003;Martin, 2003;Hassan and Woodsmith, 2004). Thus, stream animals seemingly can play an important role in the transport of gravel and sand.…”