Articles | Volume 19, issue 11
Nat. Hazards Earth Syst. Sci., 19, 2541–2549, 2019
Nat. Hazards Earth Syst. Sci., 19, 2541–2549, 2019

Brief communication 19 Nov 2019

Brief communication | 19 Nov 2019

Machine learning analysis of lifeguard flag decisions and recorded rescues

Chris Houser et al.

Related authors

Directional dependency and coastal framework geology: implications for barrier island resilience
Phillipe A. Wernette, Chris Houser, Bradley A. Weymer, Mark E. Everett, Michael P. Bishop, and Bobby Reece
Earth Surf. Dynam., 6, 1139–1153,,, 2018
Short summary
Public perceptions of a rip current hazard education program: “Break the Grip of the Rip!”
Chris Houser, Sarah Trimble, Robert Brander, B. Chris Brewster, Greg Dusek, Deborah Jones, and John Kuhn
Nat. Hazards Earth Syst. Sci., 17, 1003–1024,,, 2017
Short summary

Related subject area

Sea, Ocean and Coastal Hazards
Trivariate copula to design coastal structures
Olivier Orcel, Philippe Sergent, and François Ropert
Nat. Hazards Earth Syst. Sci., 21, 239–260,,, 2021
Short summary
Beachgoers' ability to identify rip currents at a beach in situ
Sebastian J. Pitman, Katie Thompson, Deirdre E. Hart, Kevin Moran, Shari L. Gallop, Robert W. Brander, and Adam Wooler
Nat. Hazards Earth Syst. Sci., 21, 115–128,,, 2021
Short summary
Wave height return periods from combined measurement–model data: a Baltic Sea case study
Jan-Victor Björkqvist, Sander Rikka, Victor Alari, Aarne Männik, Laura Tuomi, and Heidi Pettersson
Nat. Hazards Earth Syst. Sci., 20, 3593–3609,,, 2020
Short summary
Modeling dependence and coincidence of storm surges and high tide: methodology, discussion and recommendations based on a simplified case study in Le Havre (France)
Amine Ben Daoued, Yasser Hamdi, Nassima Mouhous-Voyneau, and Philippe Sergent
Nat. Hazards Earth Syst. Sci., 20, 3387–3398,,, 2020
Short summary
Laboratory study of non-linear wave–wave interactions of extreme focused waves in the nearshore zone
Iskander Abroug, Nizar Abcha, Armelle Jarno, and François Marin
Nat. Hazards Earth Syst. Sci., 20, 3279–3291,,, 2020
Short summary

Cited articles

Althuwaynee, O. F., Pradhan, B., Park, H. J., and Lee, J. H.: A novel ensemble decision tree-based CHi-squared Automatic Interaction Detection (CHAID) and multivariate logistic regression models in landslide susceptibility mapping, Landslides, 11, 1063–1078, 2014. 
Arozarena, I., Houser, C., Echeverria, A. G., and Brannstrom, C.: The rip current hazard in Costa Rica, Nat. Hazards, 77, 753–768, 2015. 
Barrett, G. and Houser, C.: Identifying hotspots of rip current activity using wavelet analysis at Pensacola Beach, Florida, Phys. Geogr., 33, 32–49, 2012. 
Bielders, C. L., Ramelot, C., and Persoons, E.: Farmer perception of runoff and erosion and extent of flooding in the silt-loam belt of the Belgian Walloon Region, Environ. Sci. Policy, 6, 85–93, 2003. 
Brander, R. W., Bradstreet, A., Sherker, S., and MacMahan, J.: Responses of swimmers caught in rip currents: Perspectives on mitigating the global rip current hazard, Int.J. Aquat. Res. Educ., 5, 11, 2011. 
Short summary
On many beaches, lifeguards set out flags to warn beach users of the surf and rip hazard based on the regional surf forecast and careful observation. There is a potential that the chosen flag does not accurately reflect the potential risk. Results of a machine learning analysis suggest that the greatest number of rescues occurred on days when the lifeguard flew a more cautious flag than the model predicted. It is argued that that beach users may be discounting lifeguard warnings.
Final-revised paper