Reinterpreting the Bruun Rule in the context of equilibrium shoreline models

Journal of Marine Science and Engineering
By: , and 



Long-term (>decades) coastal recession due to sea-level rise (SLR) has been estimated using the Bruun Rule for nearly six decades. Equilibrium-based shoreline models have been shown to skillfully predict short-term wave-driven shoreline change on time scales of hours to decades. Both the Bruun Rule and equilibrium shoreline models rely on the equilibrium beach theory, which states that the beach profile shape equilibrates with its local wave and sea-level conditions. Integrating these two models into a unified framework can improve our understanding and predictive skill of future shoreline behavior. However, given that both models account for wave action, but over different time scales, a critical re-examination of the SLR-driven recession process is needed. We present a novel physical interpretation of the beach response to sea-level rise, identifying two main contributing processes: passive flooding and increased wave-driven erosion efficiency. Using this new concept, we analyze the integration of SLR-driven recession into equilibrium shoreline models and, with an idealized test case, show that the physical mechanisms underpinning the Bruun Rule are explicitly described within our integrated model. Finally, we discuss the possible advantages of integrating SLR-driven recession models within equilibrium-based models with dynamic feedbacks and the broader implications for coupling with hybrid shoreline models. 
Publication type Article
Publication Subtype Journal Article
Title Reinterpreting the Bruun Rule in the context of equilibrium shoreline models
Series title Journal of Marine Science and Engineering
DOI 10.3390/jmse9090974
Volume 9
Issue 9
Year Published 2021
Language English
Publisher MDPI
Contributing office(s) Pacific Coastal and Marine Science Center
Description 974, 22 p.
Google Analytic Metrics Metrics page
Additional publication details