The purpose of wave models

Coastal engineers often need high-quality, detailed wave information as represented by the significant wave height, period and mean direction or the two-dimensional wave spectrum, at a coastal location to:
  • design engineering structures such as a breakwater, a storm surge barrier or dike,
  • plan human activities such as construction works or a salvage operation or
  • manage a sensitive, natural environment such as national marine parks or wetlands.
Such wave information is often available at open sea (from observations or from computer simulations) but not at a coastal location. The only short-term solution for solving the problem for a coastal location, is to acquire the open-sea database and to translate it to the coastal location. Occasionally this is not sufficient, particularly when extreme wave conditions must be estimated which have not (yet) occurred and are therefore missing in the database. In such cases, the database needs to be supplemented with additional numerical simulations.

SWAN is a computer wave model that provides the translation and the additional simulations. The technique of SWAN is to determine all physical processes that affect the waves as they travel from deep water to the coastal location. This involves the propagation across varying bottom topography, the growth by wind, the interaction between individual waves and the decay by wave breaking and bottom friction. The effects of currents, tides, reflection and diffraction are taken into account.

Improving methodology

The goal of Swan Support is to enhance the modelling methodology with a number of tools: a graphics extension to SWAN to improve insight of SWAN users into the results of the wave model, a Graphical User Interface to speed up the setting-up of a model for a particular site, a Swan course for beginning users, a software package enabling visual intercomparisons between SWAN runs and observations, and a package Arcadia that is helpful in setting up large numbers of SWAN runs needed for transformation of wave statitics on deep water to shallow water, or to calibrate SWAN models for particular sites.

  ©: Nico Booij (2012)