Using open source software to simulate estuarine hydronamics.

Abstract

The use of open source softwares helps users learn the internal structure of numerical models. How­ever, open source softwares usually require linking to auxiliary programs for d-ata preprocessing, post­processing, and visualization. The users also have to understand the problem thoroughly, and may at times modify the source code so that the model could better represent the natural mechanisms. An example of simulation hydro­dynamic and morphological change of Tra Khuc estuary (in Vietnam) with XBeach [1] (a 2-D hydro­dynamic modelling program) is presented, which will illustrate simple techniques we may apply when using open source programs for modelling shallow flow processes. XBeach is inher­ently a model for coastal hydrodynamic with dune erosion without modelling the river flow. In order to simulate the effect of river flow to hydrodynamic process and morphological change at the river mouth, we consider the implementation of the inflow boundary by editing XBeach program code and handling time scale and morphological factors. A test case is done with the 2005 flood, where the model results an irregular pattern of bathymetry change. Model calibration and validation is not addressed in this study.