Graduation of Matt Julseth

A Parametric Representation and Classification of Sandy Beach Profiles: Case Study of Narrabeen-Colloroy

• Professor of graduation: Dr. Ir. M. de Schipper

Coastal areas are highly dynamic systems sensitive to natural and anthropogenic change. The range of social, economic, and environmental functions served by diverse coastal environments makes understanding their geomorphology valuable. Parametric shape functions have historically been used to represent the cross shore profile of specific coastal environments. Advances in the application of data-driven modelling techniques presents opportunity to develop a unified characterization of cross shore morphology in diverse coastal environments.

However, the ability to represent diverse profile geometries using a single parametric representation has not been observed. Here, a new parametric function is presented that can effectively represent key geometric attributes of diverse cross shore profiles. Fitted parametric values were applied to group measured profiles with similar geometric attributes using both manually defined labels and an objective clustering algorithm (K-means), demonstrating effective representation of distinct profile states using parametric cluster centroids. Correlation analyses between fitted parameters and wave and tide statistics demonstrated an ability to identify expected geomorphological trends using the new parametric function.

These results demonstrate that a parametric representation of the coastal profile can be used to characterize and group diverse profile geometries, and that parametric relationships can be used to identify geomorphological trends. The application of these results provide a firm foundation for the development of a predictive coastal profile model. This model could be trained using data from diverse coastal environments in order to predict coastal profile response to changes in the metocean climate related to human interventions and climate change.