Impact of Climate Change on Breakwater Armor Design: Advancements in Reduced-Scale Physical Modeling Methodologies

Bezerra, R.O.; Bernardino, J.C.M., and Lateyron, T., 2024.Impact of climate change on breakwater armor design: Advancements on reduced-scale physical modeling methodologies. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 819-823. Charlotte (North Carolina), ISSN 0749-0208. Recent data from IPCC (Intergovernmental Panel on Climate Change) indicate a worldwide trend of sea level raising and more frequent occurrences of extreme meteorological events, including storms with higher waves. In this way, this trend should be considered into the design of new coastal and port protection infrastructure, as well as the assessment of existing breakwaters. Tests on reduced-scale physical models are a reliable alternative for validating breakwater designs, but they present challenges in accurately mapping and characterizing the damage resulting from simulated environmental condition. This paper introduces a methodology for assessing wave-induced damage to breakwaters utilizing an image capture system to detect and quantify displaced rocks in scale model tests. The system, developed at the Hydraulics Laboratory of the University of Sao Paulo, comprises two high-precision cameras and two magnetic level sensors (0.1 mm resolution), which allow an accurate planimetric surveys, presenting a different approach from conventional damage assessment techniques or even more recent stereophotography techniques. Following each scenario of wave simulation, breakwater damage is quantified applying an image processing and pixel distance calibration algorithm, which uses the waterline as a reference plan to delineates the breakwater's contour for varying water levels within the physical model. Simulations performed on two-dimensional 1:40 scale model showed an accurate armor damage assessment, with a vertical resolution of 0.1 mm and a horizontal resolution of 0.05 mm. These results point out that the system accuracy is comparable or even higher than other systems documented in previous studies. Therefore, this proposed methodology offers a viable alternative to evaluate wave-induced armor damage in breakwaters, enabling an understanding of how changes in wave regimes can impact the resilience of these structures.