Numerical depth inversion of the entrance of Leixões harbour

• Type: Article in International Conference Proceedings Book
• Date: 2009

Authors

A. Mesquita (Author) FEUP; P. Avilez-Valente (Author) FEUP

Conference proceedings International

Title: Proceedings of the Twelfth International Conference on Civil Structural and Environmental Engineering Computing

Pages: 1-16

TWELFTH INTERNATIONAL CONFERENCE ON CIVIL, STRUCTURAL AND ENVIRONMENTAL ENGINEERING COMPUTING

Funchal, Madeira, Portugal, 1-4 September 2009

Indexing

Scopus - 0 Citations

Scientific classification

FOS: Engineering and technology > Civil engineering

Other information

Authenticus ID: P-008-30V

DOI: 10.4203/ccp.91.248

Abstract (EN): A two dimensional inverse model based on the classical Boussinesq dispersive nonlinear wave equations is used for reconstruction of the bathymetry at the entrance of the Leixões harbour in the Portuguese north-western Atlantic coast. The model comprises two algorithms: a wave phase velocity inversion algorithm and a depth inversion algorithm. The wave phase velocity is computed from one or more pairs of time-lagged distributions of the free surface elevation, through a least squares method. The depth inversion algorithm computes the depth based on the knowledge of both the phase velocity and the free surface elevation at a given time instant. The differential equations for depth inversion are solved using a finite element method with triangular elements. Filtering is necessary in order to improve convergence and to avoid oscillating solutions, and is based on the finite element discretization. This is the first part of a more general project: part 1 - algorithmic development, with numerical generation of free surface elevation profiles; part 2 - model calibration, with laboratory produced profiles; part 3 - field application with profiles obtained in the sea (e.g. radar, satellite). In this first part, the spatial distributions of the free surface elevation were numerically generated by the FUNWAVE program. Regular waves with height, period and direction of propagation typical of the Portuguese coast were used. Free surface elevation distributions in the neighbourhood of the Leixões harbour were extracted which allowed, through inverse modelling, to estimate first the wave velocity and then the local depth distributions. Analysis of the local and global errors are produced. The numerically estimated bathymetry is compared to the measured one. A good agreement is shown all over the domain but near the boundaries. Nevertheless the reconstructed bathymetry is excessively smooth. © Civil-Comp Press, 2009.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 16