scholarly journals Effects of Density‐Driven Flows on the Long‐Term Morphodynamic Evolution of Funnel‐Shaped Estuaries

2018 ◽  
Vol 123 (11) ◽  
pp. 2901-2924 ◽  
Author(s):  
Maitane Olabarrieta ◽  
W. Rockwell Geyer ◽  
Giovanni Coco ◽  
Carl T. Friedrichs ◽  
Zhendong Cao
Author(s):  
M. van der Wegen ◽  
Zheng Bing Wang ◽  
H. H. G. Savenije ◽  
J. A. Roelvink

2021 ◽  
Author(s):  
Niccolò Ragno ◽  
Nicoletta Tambroni ◽  
Michele Bolla Pittaluga

The morphodynamic evolution of river deltas is intimately tied to flow and sediment partitioning at bifurcations. In this work, we investigate the long-term equilibrium configuration of a simple delta network using an analytical model, which accounts for the effect of small tidal oscillations.Differently from individual bifurcations, where tidal action is always a stabilizing factor, in the case of a tree-like delta with multiple bifurcations a dual response emerges.Specifically, depending on the values of four reference parameters function of tidal amplitude, upstream flow conditions, and on the geometry of the channels, tides can either promote or discourage an unbalanced discharge distribution. This behavior primarily concerns the apex bifurcation, which is affected by the variations of the relative tidal amplitude at the internal nodes. In turn these variations depend on how flow and sediment are diverted upstream. Finally, we discuss the outcomes of the model performing a qualitative comparison with field and experimental tide-influenced deltas. Results highlight the need of including in a unified scheme river-influenced (i.e. depositional) and tide-influenced (i.e. erosional) effects.


Geomorphology ◽  
2021 ◽  
pp. 108057
Author(s):  
Yong He ◽  
Xiaojian Liu ◽  
Zihao Duan ◽  
Cheng Liu ◽  
Peng Hou ◽  
...  

2020 ◽  
Vol 8 (6) ◽  
pp. 421
Author(s):  
Siegmund Nuyts ◽  
Michael O'Shea ◽  
Jimmy Murphy

This research presents a study on the morphodynamic evolution of the Rossbeigh coastal barrier and its dune system, located in Dingle Bay, County Kerry, Ireland. The study examines the evolution of the system over a 19-year period (2001–2019) through remote sensing, geographic information system (GIS) analysis, and field-based surveys. This research provides an ideal opportunity to examine a natural erosion event, referred to as cannibalization on a coastal barrier and its dune system. Since the beginning of this century, significant erosion has been visible on the coastal barrier, with the erosion eventually leading to a breaching event in the winter of 2008/2009. Over the study period, analysis has shown that the vegetated dunes decreased by more than 60 percent, the width of the breached area reached a maximum width of over 1 km and a change in orientation and appearance on the coastal barrier has been quantified. The analysis identifies a growing drift-aligned zone, contrasted with a reduction in the stable swash-aligned zone. Significantly, the point between these zones (i.e., the hinge point) has been shown to have moved by more than 1 km also. The migration of this hinge point and cannibalization of the dunes are illustrated. Finally, the potential mechanism for beach healing is identified, utilizing the rich datasets collected during the study, thus providing an insight into the long-term behavior of a dynamic coastal barrier system undergoing naturally driven cannibalization.


2008 ◽  
Vol 77 (3) ◽  
pp. 385-395 ◽  
Author(s):  
Harshinie Karunarathna ◽  
Dominic Reeve ◽  
Mark Spivack

2018 ◽  
Vol 33 (5) ◽  
pp. 1039-1048 ◽  
Author(s):  
Leonardo Vignoli ◽  
Fabiana Velletrani ◽  
Cristina Venditti ◽  
Luca Luiselli ◽  
Yitzhak Yadid ◽  
...  

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