Composite Beaches and Dynamic Revetments Network Webinar #7 – Wednesday 13th May

[Chris Blenkinsopp]

Dear all,

The seventh webinar on composite beaches and dynamic revetments will take place next week on Wednesday 13th May at 15:00 GMT (160:00 BST, 17:00 CET, 10:00 EST, 07:00 PST, ...) on Teams at this link:

https://teams.microsoft.com/meet/364565519766077?p=FrgiH5197d7OJInsyR

Meeting ID: 364 565 519 766 077

Passcode: Po7Gq6g8

Schedule

• 15:05-15:30 Paul Bayle (Delft University of Technology, Netherlands) – Dynamic stability and sand infiltration of a dynamic cobble berm revetment: field measurement in North Cove, USA.

• 15:35-16:00 Amaia Ruiz de Alegria Arzaburu (Universidad Autónoma de Baja California, Mexico) – Effects of cobble extraction on two beaches in Northwestern Baja California.

A summary of the talks is provided below. The format will be 15 minutes presentation and 10 minutes for questions/discussion.

We look forward to seeing you.

Chris

Paul Bayle (Delft University of Technology, Netherlands) – Dynamic stability and sand infiltration of a dynamic cobble berm revetment: field measurement in North Cove, USA.

Title: Dynamic stability and sand infiltration of a dynamic cobble berm revetment: field measurement in North Cove, USA.

 

Abstract: The dynamic cobble berm revetment located in North Cove, WA, USA, was monitored over a spring tidal cycle. A representative 60 m alongshore section was monitored over 10 days using 2D laser scanner (lidar) measurements, GPS ground elevation surveys, Radio Frequency Identification of individual cobbles and revetment thickness measurements. These data were used to assess the dynamic behaviour and functionality of the revetment throughout the measurement campaign. The revetment showed a dynamic stability and the capacity to quickly reshape under changing hydrodynamic conditions. The revetment also managed to recover some of the lost volume under moderate wave conditions. The revetment behaviour was found to be influenced by variation in the cobble-sand matrix, a key processus responsible for most of the overall volume changes and stability of the revetment. A conceptual model of the internal sand dynamics will be presented.

Amaia Ruiz de Alegria Arzaburu (Universidad Autónoma de Baja California, Mexico) – Effects of cobble extraction on two beaches in Northwestern Baja California.

Title: Effects of cobble extraction on two beaches in Northwestern Baja California

Abstract:  Effects of cobble extraction on two beaches in Northwestern Baja California. I will present the morphological response of two beaches exposed to prolonged cobble removal along the Pacific coast of Baja California, where this activity supports local low-income communities. One site (San Jacinto) is a cobble beach overlying a rocky platform, while the other (La Chorera) is a former composite cobble–sand beach that has evolved into a predominantly sandy system following sustained extraction. Morphological trends reveal contrasting responses: San Jacinto has experienced chronic shoreline recession of nearly 0.5 m/year, whereas La Chorera shows apparent long-term shoreline stability (+0.2 m/year). However, short-term subaerial volume changes between 2023 and 2025 indicate greater erosion at La Chorera (50 m³/m) compared to San Jacinto (32 m³/m). These findings suggest that beach response to cobble removal is strongly influenced by underlying sediment composition.

Dr Chris Blenkinsopp
Head of Civil Engineering
Department of Architecture and Civil Engineering
University of Bath
Bath
BA2 7AY
United Kingdom
 

t: +44 (0)1225 386715
e: c.blen...@bath.ac.uk