Videos, Talks & Stuff

This video shows the process of bank collapse events induced by fluvial processes (bank height 0.4 m, water depth 0.15 m). Several deep tension cracks were observed on the bank top, leading to a massive toppling failure.

Zhao et al., (2020), Laboratory Experiments of Bank Collapse: The Role of Bank Height and Near‐Bank Water Depth, J.Geophys.Res.

Zhang et al., (2021). Experimental and numerical modeling of overhanging riverbank stability. J.Geophys.Res.

This video documents seepage-induced bank collapse events, with bank height of 0.6 m, and seepage head of 0.6 m on the left part and 0.45 m on the right part. Note that tension failure occurs under high seepage gradient conditions.

This model was originally developed by Brad Murray (Duke University) and Rob Thieler (USGS). The version in the movie results from modifications following a collaboration between Brad, Malcolm Green and Giovanni. The model was further improved by Evan Goldstein. The reference describing this simulation is:

Coco, G., Murray, A. B., & Green, M. O. (2007). Sorted bed forms as self‐organized patterns: 1. Model development. Journal of Geophysical Research: Earth Surface, 112(F3).

Check out this great video from Bruno Castelle (University of Bordeaux). The video shows results of Bruno's numerical model of surf zone morphodynamics and rip channel formation. Bruno has done a lot of work on the topic and you should definitely check out his work. The key reference for this video is:

•  Dubarbier, B., Castelle,  B., Ruessink, G., Marieu, V. (2017). Mechanisms controlling the  complete accretionary beach state sequence. Geophysical Research  Letters, 44 (11), 5645-5654.  

This video, prepared by NIWA and Karin Bryan (University of Waikato) consists of a sequence of orthorectified images. Each image is actually the average of 600 images collected each hour during daytime. The averaging process emphasizes the presence of sandbars (white areas, where waves break) and rip channels (area with no white). It's quite incredible how mobile the rips are.

Key reference:

Gallop, S. L., Bryan, K. R., Coco, G.,  & Stephens, S. A. (2011). Storm-driven changes in rip channel  pat

This vodeo was prepared by Zeng Zhou (Hohai University) at the time of his PhD in Spain.  The simulation tries to reproduce the laboratory experiments of the Padua group ( 

Stefanon, Luana, Luca Carniello,  Andrea D'Alpaos, and Andrea Rinaldo. "Signatures of sea level changes on  tidal geomorphology: Experiments on network incision and retreat." Geophysical Research Letters 39, no. 12 (2012).). The key reference is:

Zhou, Z., Olabarrieta, M., Stefanon,  L., D'Alpaos, A., Carniello, L., & Coco, G.

Here is an old goodie, a simulation using a CA  model that reproduces beach cusp formation. Graphics and colours look old (hey, it was 1999!) but I think it could still be used in class.

If you need a reference, please use   

• Coco, G., Huntley, D.A., and O’Hare, T.J. (2000) Investigation of a self-organisation model for beach cusp formation and development, Journal of Geophysical Research, 105(C9), 21991-22002.

Another 'vintage' video. This one shows the development of crescentic bars (or rip channels). Bottom plot shows the difference between actual and initial water depth  (once the perturbation is large enough, one can also see it on the top subplot). Useful reference:   

• Caballeria, M., Coco, G., Falqués, A., and Huntley, D.A., 2002, Self-organization mechanisms for the formation of nearshore crescentic sand bars, Journal of Fluid Mechanics, 465: 379-410.

A video showing ripple evolution under step-change of wave condition. The power spectral density is derived from photos taken during the experiment. The dominant wavenumber indicates the dominant ripple spacing. 

Useful reference: 

• Jin, C., Coco, G., Tinoco, R. O., Goldstein, E. B., & Gong, Z. (2019). Laboratory experiments on the role of hysteresis, defect dynamics and initial perturbation on wave-generated ripple development. https://doi.org/10.1016/j.ecss.2019.05.003

Check out this video recording the fascinating edge waves. The standing edge waves formed under the regular incident waves with the deep-water wave height H = 0.2 m and wave period T = 2.4  s.

Check this reference for more details:

Ding, X., Coco, G., Guza, R. T., Garnier, R., Whittaker, C., Dalrymple, R. A., ... & Vittori, G.  (2018). Intermittent subharmonic edge wave excitation with random  incoming waves. AGUFM, 2018, OS23G-1698.

In this experiment, the regular incident waves had a different wave period - T = 3.6 s. The resulted subharmonic edge waves had a larger period (7.2 s) and a longer wavelength (16 m) compared to those in the experiment with T = 2.4 s (which had the period 4.8 s and wavelength of 8 m).

Here's Giovanni's keynote at Coastal Dynamics 2021

Here's Giovanni's EuroCoast Seminar

Here's Giovanni's Inaugural lecture