Data

When no zone map is specified on the "Domain" page or "Whole domain" is selected for the type of domain input, the format of the Chezy number, C, the Manning number, M, and the effective grain diameter, d₅₀, can be specified in one of three ways

·         Constant (in time and domain)

·         Constant in time, varying in domain

·         Varying in time and domain

For the case with values varying in domain you have to prepare a data file containing the Chezy number, the Manning number or the grain diameter 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 piecewise constant inter­polation is used to map the data. If a dfs2-file is used bilinear interpolation is used to map the data. If the data is varying in time the data must cover the complete simulation period. The time step of the input data file does not, how­ever, have to be the same as the time step of the hydrodynamic simulation. A linear interpolation will be applied if the time steps differ.

When "Zone map" is specified for the type of domain input and the resistance type is specified as "Chezy number",  "Manning number" (standard formula­tion) or "Wave induced bed resistance", you must specify a constant Chezy number, Manning number or grain diameter for each zone in the domain.

When "zone map" is specified for the type of domain input and the resistance type is specified as "Manning number" (flow dependent formulation) you must for each zone specify the type of flow dependent Manning number as either

·         Function of depth

·         Function of flux

In addition, you must for each zone specify a discrete curve for the Manning number as function of either the water depth or flux. The points are taken from the dialog or from a file. The file format is an ascii file with two space separated items for each of the points on separate lines. The first item is the depth/flux and the second item is the Manning number. The list of water depth/flux values must have increasing values. There must be at least two points on the curve. Given a water depth at an element in the domain, the Manning number is calculated using linear interpolation. If the water depth/flux is below the lower limit or above the upper limit, the Manning num­ber is given the value corresponding to the limit.

When no zone map is specified on the "Domain" page or "Whole domain" is selected for the type of domain input, the format of the drag coefficient, the roughness height, k_s, and the grain diameter, d₅₀, can be specified in one of three ways

·         Constant (in time and domain)

·         Constant in time, varying in domain

·         Varying in time and domain

For the case with values varying in domain you have to prepare a data file containing the drag coefficient, the roughness height or the grain diameter 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 piecewise constant inter­polation is used to map the data. If a dfs2-file is used bilinear interpolation is used to map the data. If the data is varying in time the data must cover the complete simulation period. The time step of the input data file does not, how­ever, have to be the same as the time step of the hydrodynamic simulation. A linear interpolation will be applied if the time steps differ.

When "Zone map" is specified for the type of domain input and the resistance type is specified as "Quadratic drag coefficient",  "Roughness height" or "Wave induced bed resistance", you must specify a constant drag coefficient, roughness height or grain diameter for each zone in the domain.