Statistical Trend of Exposure of Santos Port (Brazil) to Extreme Events of Sea-Level Rise and Storminess

Alfredini, P.; Arasaki, E., and Puia, H., 2024. Statistical trend of exposure of Santos Port (Brazil) to extreme events of sea-level rise and storminess. 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. 205-209. Charlotte (North Carolina), ISSN 0749-0208. Many studies in the last two decades, including the Organization for Economic Cooperation and Development (OECD) and the German Agency for International Cooperation (GIZ), highlighted the vulnerability of the city of Santos (Brazil) to coastal flooding, because of climate change in sea-level rise and increased storminess. In addition to the increasing exposure of the population growth, which tends to occupy low-lying areas, no less important is the risk of the infrastructure assets, mainly of Santos Port, the largest in the Southern Hemisphere. The objective of this paper is to present the main results of this exposure from 1940s onwards. From data of two coastal tide gauges, with 3 Lunar nodal period of 18.61 years, it was possible to highlight a growing trend of sea-level rise, between 2.5 to 4.5 mm/year. These trends were compared with international guidelines, like IPCC models, and estimated for the coming decades. The local wave climate was obtained from the records of an oceanographic buoy, located at around 200 m depth, recording a series from 2011 to 2018, and from a coastal buoy in Santos Bay, which has a series starting in 2015. Therefore, it was possible to correlate the wave heights of extreme events selected by the POT (Peak Over Threshold) method between deep waters and coastal waters. To assess the trend of increasing frequency and severity of storminess, a statistical calibration of the NOAA/NCEP WAVEWATCH III® and of the ECMWF ERA 5 oceanographic models was carried out with the oceanographic buoy data, aiming to extend the behaviour analysis of the wave climate from 1940 to 2023. Applying statistical methods, it was possible in a first approach to identify an increasing incidence and heights of storm surges.