Geometric characteristics and evolution of a tidal channel network in experimental setting

Abstract

This paper reports on a laboratory study that aims to reproduce a tidal channel network, in order to enhance the understanding of the morphodynamic evolution of the channel characteristics as the network expands and finally reaches equilibrium. A high-resolution laser system scanned the bed topography at different time steps creating multiple digital elevation models of the channel network. Two hundred and seventy individual channel segments are analyzed and cross-correlated in terms of their width, depth and length.The laboratory results show positive linear correlations between depth and width as well as between length and width of channel segments of the network configuration at final equilibrium. In a downstream direction, channels appear to widen more than they deepen, indirectly a sign that discharge has a stronger control on channel width than on depth. In contrast to fluvial drainage networks that commonly display fractal and scale-invariant behavior, the geometric properties of the experimental tidal creek network shows scale dependence. Channel attributes exhibit consistent patterns of exponentially decreasing abundance, with increasing creek length, depth and width. The nature of the observed exponential distributions within creek attributes (width, depth, length) allows for statistical predictability of relative creek attribute dimensions downstream and through time.

Signatures of sea level changes on tidal geomorphology: Experiments on network incision and retreat

“…Some studies suggest tidalchannel development to be the result of depositional rather then erosional processes [e.g., Redfield, 1965;Hood, 2006], whereas others consider erosion as the dominant process [e.g., Fagherazzi and Sun, 2004;Perillo et al, 2005;D'Alpaos et al, 2005D'Alpaos et al, , 2007bVlaswinkel and Cantelli, 2011]. In the erosional scenario, differential erosion drives the evolution: Network configuration is driven by local excess in the bed shear stress compared to the critical threshold for sediment motion, as modelled in this experimental context.…”

“…These models deepen our understanding of tidal network growth, otherwise analyzed solely on the basis of field observations and related conceptual models [e.g., Redfield, 1965;Allen, 1997;Perillo et al, 2005;Hood, 2006;D'Alpaos et al, 2007b;Hughes et al, 2009]. In two cases tidal network initiation and development have been addressed with physical models [Stefanon et al, 2010;Vlaswinkel and Cantelli, 2011]. These studies showed that laboratory experiments can successfully model tidal network dynamics.…”

Modeling sorting dynamics of cohesive and non-cohesive sediments on intertidal flats under the effect of tides and wind waves

“…However, we also realize that field observations can be restrained by many practical factors such as severe local environmental conditions (e.g., extreme weather), human interventions and limited availability of advanced measurement facilities. In this regard, controlled laboratory experiments may be another promising alternative to further the understanding of intertidal flat morphodynamics (Stefanon et al, 2010;Vlaswinkel and Cantelli, 2011).…”

Experimental delta evolution in tidal environments: Morphologic response to relative sea‐level rise and net deposition

“…are typically not well preserved (Dalrymple and Choi, 2007). Recent studies demonstrated that physical experiments are capable of reproducing several typical tidal features, such as ebb deltas (Kleinhans et al, 2012), tidal channel networks (Stefanon et al, 2010;Vlaswinkel and Cantelli, 2011) and tidal estuaries (Kleinhans et al, 2014a). Recent studies demonstrated that physical experiments are capable of reproducing several typical tidal features, such as ebb deltas (Kleinhans et al, 2012), tidal channel networks (Stefanon et al, 2010;Vlaswinkel and Cantelli, 2011) and tidal estuaries (Kleinhans et al, 2014a).…”