Storm surge hydrodynamic modelling

Nuno Ricardo Costa Marujo da

Key information

Authors:

Nuno Ricardo Costa Marujo da (Nuno Ricardo Costa Marujo da Silva)

Supervisors:

Maria Amélia Vieira da Costa Araújo (Maria Amélia Vieira da Costa Araújo); António Alexandre Trigo Teixeira (António Alexandre Trigo Teixeira)

Published in

November 25, 2011

Abstract

In the present thesis a storm surge event, which hit the Portuguese coast between 14th - 16th October 1987, is modelled using the ADCIRC model. Considering the two hydrodynamic scales existing in the interest area, the simulations considered two different domains to account for different processes. A large domain including part of the Atlantic Ocean was used to simulate the storm surge event along the Portuguese coast and a second smaller domain to capture the Lima estuary storm surge response. Prior to simulations, a field survey was carried out to create a local geoid undulation model (LGUM) and improve the existing bathymetry in the Lima estuary. In this survey, GNSS devices were used to acquire data in identified areas, where information was lacking, and ellipsoidal heights in geodetic and levelling marks. The acquired data were post processed and combined with the existing datasets to create a LGUM and a Digital Terrain Model (DTM) for the Lima estuary. The two models used were calibrated using the astronomy forcing and changing the most important model parameters. Thereafter the interaction between astronomy and meteorology was assessed considering these jointly and separately. The river flow was considered as a meteorological forcing agent for the estuarine domain. The obtained results show a preponderance of the friction coefficient over other parameters and the importance of considering a variable Coriolis parameter for large domains in latitude. The meteorology was found to have non linear interaction with the astronomy in both domains, even when considering the river flow.