WMS:GSSHA

Gridded Surface Subsurface Hydrologic Analysis (GSSHA) is a two-dimensional finite difference rainfall/runoff model. A finite difference grid is used to establish the computational domain and parameters for surface runoff. The GSSHA model is fully coupled with hydraulic stream flow/routing models. Parameters for stream channels are defined using arcs and then mapped to the appropriate underlying grid cells.

Features of GSSHA include 1D stream flow and infiltration, 2D overland flow and groundwater, and full coupling between the groundwater, shallow soils, streams, and overland flow. "Sediment and constituent fate and transport are simulated in the shallow soils, overland flow plane, and in streams and channels. GSSHA can be used as an episodic or continuous model where soil surface moisture, groundwater levels, stream interactions, and constituent fate are continuously simulated. The fully coupled groundwater to surface-water interaction allows GSSHA to model basins in both arid and humid environments."

The GSSHA model can be added to a paid edition of WMS.

GSSHA Menus

There are two GSSHA menus in WMS:

• When in the Map module, the GSSHA menu is available when a GSSHA coverage is selected. See here for more details.
• When in the 2D Grid module, the main GSSHA menu is available. See here for more details.

Cell Properties

The 2D grid cell properties include an I,J location and a scalar or index map value. The scalar or index map value is associated with the currently selected dataset in the Project Explorer and can be edited in the Properties Window. The I,J location can be viewed but not edited in the Properties Window. The 2D grid contours are a way of visualizing the spatial variation of the scalar or index map values for the selected dataset.