Storm Surge Assessment Methodology Based on Numerical Modelling

Abstract

Coastal zones face severe weaknesses and high-risk situations due to coastal threats like erosion and storms and due to an increasing intensive occupation. Tropical storms events can contribute to the occurrence of these situations, by causing storm surges with high water levels and, consequently, episodes of waves overtopping and coastal flooding. This work aims to describe a methodology to estimate the storm surge occurrences in the Portuguese coastal zone, recurring to historical tropical storms data that occurred in the vicinity of Portugal and to numerical modeling of its characteristics. Delft3D software together with DelfDashboard tools were applied for the numerical modelling. An automatic generation procedure of storms was implemented based on the few available historical storms data characteristics. Obtained results allows to characterize storm surges along the Portuguese coast, identifying the most vulnerable areas and, consequently contributing for its proper planning and management.

Dominant processes that amplify the swell towards the coast: the Nazaré Canyon and the giant waves

“…Changes in the frequency or intensity of extreme weather, and climate events, are likely to have notable effects on an energetic environment such as the Portuguese northwestern coast (Gomes et al, 2018;Santos et al, 2018). Even because on the Portuguese Atlantic coast we can find several deep incisions on the continental shelf, with steep rocky sides giving rise to successively narrower canyons that channel energy and increase the waves towards the coast.…”

“…In winter significant wave heights of 9 m or more are achieved during storms (Rosa-Santos et al, 2009). Examples are the Rafael, Hercules, Stephanie and Joaquin storms, which occurred between 2012 and 2015 (NOAA, 2022;Santos et al, 2018). A history of the most important coastal storms in the vicinity of the Portuguese northwestern coast (years 1842-2016) is presented in Gomes et al (2018) study.…”

“…To the south of Aveiro there are littoral sediment losses to the Aveiro Canyon, periodic retentions by coastal structures and port interventions (dredging) that lead to intense coastal erosion (Santos et al, 2018;Antunes do Carmo, 2019).…”

A Comprehensive Review of Assessing Storm Surge Disasters: From Traditional Statistical Methods to Artificial Intelligence-Based Techniques

“…Lara Santos et al employed the Delft3D model to evaluate storm surge risks along the Portuguese coastline. They simulated historical storm surge events and reconstructed the genesis, development, and disaster processes of storm surges, while also assessing changes in water levels and flood inundation extents for various storm surge cases, offering a scientific basis for local disaster prevention and mitigation planning [26]. In 2023, Mentaschi et al conducted a global-scale simulation of storm surges and waves using the SCHISM model.…”