Data

For the case with spatially varying surface elevation you have to prepare a data file containing the surface elevation before you set up the hydrodynamic simulation. The file must be a 2D unstructured data file  (dfsu) or a 2D grid data file (dfs2). The area in the data file must cover the model area. If a dfsu-file is used, piecewice constant interpolation is used to map the data. If a dfs2-file is used, bilinear interpolation is used to map the data. In case the input data file contains a single time step, this field is used. In case the file contains several time steps, e.g. from the results of a previous simulation, the actual starting time of the simulation is used to interpolate the field in time. Therefore the starting time must be between the start and end time of the file.

For the case with spatially varying surface elevation and velocities you have to prepare one or two data files before you set up the hydrodynamic simula­tion.

In case of a 2D simulation one file is necessary. The file must contain the total water depth and the velocity components in the x- and y-directions. The file must be a 2D unstructured data file  (dfsu) or a 2D grid data file (dfs2). The area in the data file must cover the model area. If a dfsu-file is used piecewice constant interpolation is used to map the data. If a dfs2-file is used bilinear interpolation is used to map the data.

In case of a 3D simulation two files are necessary.One containing the total water depth and one containing the velocity components in the x- and y-direc­tions and the vertical velocity before you set up the hydrodynamic simulation. For the shallow water equations, the vertical velocity must be given in the sigma coordinate system. The first file must be a 2D unstructured data file  (dfsu) or a 2D grid data file (dfs2) and the second file must be a 3D unstruc­tured data file (dfsu) or a 3D grid data file (dfs3). The area in the data file must cover the model area. If a 2D dfsu-file is used piecewice constant interpola­tion is used to map the data. If a 3D dfsu file is used the mesh in the data file must match exactly the mesh in the simulation. If a dfs2-file or a dfs3-file is used bilinear interpolation is used to map the data.

In case the input data file contains a single time step, this field is used. In case the file contains several time steps, e.g. from the results of a previous simulation, the actual starting time of the simulation is used to interpolate the field in time. Therefore the starting time must be between the start and end time of the file.