Academic Journal

Semi-empirical forecast modelling of rip-current and shore-break wave hazards

Bibliographic Details
Title: Semi-empirical forecast modelling of rip-current and shore-break wave hazards
Authors: Castelle, Bruno, Dehez, Jeoffrey, Savy, Jean-Philippe, Liquet, Sylvain, Carayon, David
Contributors: Castelle, Bruno
Source: Natural Hazards and Earth System Sciences, Vol 25, Pp 2379-2397 (2025)
Publisher Information: Copernicus GmbH, 2025.
Publication Year: 2025
Subject Terms: Environmental sciences, QE1-996.5, [SDU.STU.GM] Sciences of the Universe [physics]/Earth Sciences/Geomorphology, Geography. Anthropology. Recreation, GE1-350, Geology, [SDU.STU.OC] Sciences of the Universe [physics]/Earth Sciences/Oceanography, [SPI.GCIV.RISQ] Engineering Sciences [physics]/Civil Engineering/Risques, Environmental technology. Sanitary engineering, TD1-1066
Description: Sandy beaches are highly attractive but also potentially dangerous environments for those entering the water as they can be exposed to physical hazards in the surf zone. The most severe and widespread natural bathing hazards on beaches are rip currents and shore-break waves, which form under different wave, tide, and morphological conditions. This paper introduces two new, simple semi-empirical rip-current and shore-break wave hazard forecast models. These physics-informed models, which depend on a limited number of free parameters, can be used to compute the time evolution of the rip-current flow speed V and shore-break wave energy Esb. These models are applied to a high-energy mesotidal–macrotidal beach, La Lette Blanche, in southwest France, where intense rip-currents and shore-break wave hazards co-exist. Hourly lifeguard-perceived hazards collected during patrolling hours (from 11:00 a.m. to 07:00 p.m. LT (UTC+2)) during July and August of 2022 are used to calibrate the two models. These data are also used to transform V and Esb into a five-level scale from 0 (no hazard) to 4 (hazard maximised). The model accurately predicts rip-current and shore-break wave hazard levels, including their modulation by tide elevation and incident wave conditions, opening new perspectives for forecasting multiple surf-zone hazards on sandy beaches. In addition, daily-mean hazard forecasts demonstrate even greater predictive skill, which is important for conveying straightforward messages to the general public and lifeguard managers. The approach presented here only requires a limited number of beach morphology metrics and allows for the prediction of surf-zone hazards on beaches where wave and tide forecasts are available.
Document Type: Article
Other literature type
File Description: application/pdf
Language: English
ISSN: 1684-9981
DOI: 10.5194/nhess-25-2379-2025
Access URL: https://nhess.copernicus.org/articles/25/2379/2025/
https://doaj.org/article/bf550611c0314b96ae7f1021d13096f1
https://hal.science/hal-05167671v1
https://doi.org/10.5194/nhess-25-2379-2025
https://hal.science/hal-05167671v1/document
Rights: CC BY
Accession Number: edsair.doi.dedup.....e4550ce4dbb57bfaa7c7663e01435511
Database: OpenAIRE
Description
ISSN:16849981
DOI:10.5194/nhess-25-2379-2025