Model Construction:Global parameters

The global parameters of a simulation refer to the input control and other parameters not assigned on a cell-by-cell basis; e.g., the numerical method for computing overland flow, the computa­tional time-step and total simulation time, and whether to activate certain model options such as channel routing, long-term simulations, infiltration, evapotranspiration, groundwater interaction, etc.

To have WMS allocate the memory required for development and storage of GSSHA model parameters, you must first initialize a simulation. This is usually done when creating a grid, because WMS prompts the user whether or not to do so. However, the simulation parameters can be initialized or deleted using the identified buttons in the GSSHA Job Control Parameters dialog. Data necessary to run a GSSHA simulation are determined based on the settings in the GSSHA Job Control Parameters dialog (Figure 4). A better description of the various options is provided in the next several sections.

Figure 4. GSSHA Job Control dialog in WMS. This dialog is used to select model options and global parameters needed by GSSHA. The Output Control dialog, accessible from the Output Control button in the center bottom, is used to indicate the desired time-series maps that GSSHA can output, such as the depth of water on the overland flow plane.

Related Topics

GSSHA Wiki Main Page
Primer Main Page

Model Construction

Global parameters

Total time

Time-step

Outlet information

Units

Defining a uniform precipitation event

Describing overland flow

Overland flow routing options

Verifying the basic model

Editing the grid to correct elevation errors

Determining an appropriate time-step

Running GSSHA