User:Jcreer/SMS:GSSHA Coverages

The GSSHA model makes use of the simulation based modeling approach. This requires defining coverages in the Map module to build the components for use in the GSSHA simulation.

A GSSHA simulation makes use of the following coverage types:

• Boundary Conditions

Boundary Conditions Coverage

Arc Properties

• Channel –
  • Channel type –
    • Trapezoidal – Trapezoidal channels are used to define channel routing in GSSHA models. WMS automatically assigns a link number to trapezoidal channel arcs. By default, the geometric parameters of the trapezoidal channel are applied to the entire channel, although it is possible to assign both upstream and downstream geometric parameters for the channel by turning on [2] Geometry in the Properties dialog. GSSHA will interpolate a cross section at each node in the link using the upstream and downstream channel geometries.
      • Manning's n (MANNINGS_N): – Manning's n roughness coefficient. Appears under both Channel options. Enter the Manning's N integer here.
      • Depth (m) (BANKFULL_DEPTH): – The maximum depth of the channel represented by the GSSHA feature arc in meters. Only available for feature arc types of "Trapezoidal".
      • Bottom width (m) (BOTTOM_WIDTH): – The width of the bottom of the channel in meters. Only available for feature arc types of "Trapezoidal channel".
      • Side slope (H:V) (SIDE_SLOPE): – The horizontal value to one unit of vertical rise. Only available for feature arc types of "Trapezoidal channel".
    • Cross-section – The profile of irregular cross sections are defined using XY coordinate pairs. GSSHA computes conveyance parameters including area, top width, and conveyance at incremental depths of flow up to the maximum depth specified in the Max conveyance depth column of the table.
      • Manning's n (MANNINGS_N): – Manning's n roughness coefficient. Appears under both Channel options. Enter the Manning's N integer here.
      • Cross section:
        • Edit XY Series – Selecting this bring up the XY Series Editor dialog.
  • Most downstream arc of stream network –
  • Output hydrograph at downstream end –
  • Specify point source at upstream end –
• Overland Flow BC –
  • Overland Flow BC Type: –
    • Constant slope –
      • Constant slope: – Enter integer here
    • Constant stage (water surface elevation) –
      • Constant stage (water surface elevation): – Enter integer here
    • Variable stage (water surface elevation) – Define a WSE curve
      • Variable stage (water surface elevation) – Click on Edit XY Series... to bring up the XY Series Editor dialog.
    • Variable flow (cms discharge) – Define a discharge curve
      • Variable flow (cms discharge): – Click on Edit XY Series... to bring up the XY Series Editor dialog.
    • Variable flow (cfs discharge) – Define a discharge curve
      • Variable flow (cfs discharge): – Click on Edit XY Series... to bring up the XY Series Editor dialog.

Point Properties

• Overland Flow BC –
  • Overland Flow BC Type: –
    • Constant slope –
      • Constant slope: – Enter integer here
    • Constant stage (water surface elevation) –
      • Constant stage (water surface elevation): – Enter integer here
    • Variable stage (water surface elevation) –
      • Variable stage (water surface elevation) – Click on Edit XY Series... to bring up the XY Series Editor dialog.
    • Variable flow (cms discharge) –
      • Variable flow (cms discharge): – Click on Edit XY Series... to bring up the XY Series Editor dialog.
    • Variable flow (cfs discharge) –
      • Variable flow (cfs discharge): – Click on Edit XY Series... to bring up the XY Series Editor dialog.