River mouths building into standing bodies of water have strikingly varied growth habits. This presents a compelling pattern formation problem that is also of great practical relevance for subsurface prediction and managing coastal wetlands. Here we present a generalized 2.5-dimensional potential vorticity (PV) theory that explains sedimentation patterns of a sediment-laden stationary jet by coupling an understanding of vorticity with suspended sediment concentration fields. We explore the physical meaning of this new sediment-PV definition, and its impact on outflow depositional patterns, by analyzing data from a shallow wall-bounded plane jet experiment and by discussing new theoretical insights. A key result is that lateral advection and diffusion of suspended sediment are directly proportional to jet vorticity, a feature that reveals the mechanistic process that forms elongated channels by focused levee deposition. The new PV theory constitutes a more generalized mathematical framework that expands the Rouse theory for the equilibrium of suspended sediment. Key Points <list list-type="bulleted" id="jgrf20172-list-0001"> <list-item id="jgrf20172-li-0001">Lateral advection/diffusion of suspended sediment are proportional to vorticity <list-item id="jgrf20172-li-0002">Our mathematical framework generalizes the Rouse theory for suspended sediment <list-item id="jgrf20172-li-0003">We probe processes that lead to the formation of various channel patterns
Hydrodynamic and suspended sediment transport controls on river mouth morphology / Falcini, Federico; A., Piliouras; Garra, Roberto; A., Guerin; D. J., Jerolmack; J., Rowland; C., Paola. - In: JOURNAL OF GEOPHYSICAL RESEARCH. EARTH SURFACE. - ISSN 2169-9003. - STAMPA. - 119:1(2014), pp. 1-11. [10.1002/2013jf002831]
Hydrodynamic and suspended sediment transport controls on river mouth morphology
FALCINI, FEDERICO;GARRA, ROBERTO;
2014
Abstract
River mouths building into standing bodies of water have strikingly varied growth habits. This presents a compelling pattern formation problem that is also of great practical relevance for subsurface prediction and managing coastal wetlands. Here we present a generalized 2.5-dimensional potential vorticity (PV) theory that explains sedimentation patterns of a sediment-laden stationary jet by coupling an understanding of vorticity with suspended sediment concentration fields. We explore the physical meaning of this new sediment-PV definition, and its impact on outflow depositional patterns, by analyzing data from a shallow wall-bounded plane jet experiment and by discussing new theoretical insights. A key result is that lateral advection and diffusion of suspended sediment are directly proportional to jet vorticity, a feature that reveals the mechanistic process that forms elongated channels by focused levee deposition. The new PV theory constitutes a more generalized mathematical framework that expands the Rouse theory for the equilibrium of suspended sediment. Key PointsI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
