WMS:Rational Method Edit Parameters

Rational Method parameters dialog.

Like the other models supported by WMS, the Rational Method can be defined for a watershed/catchment developed from feature objects, DEMs, or TINs, or built using the tools provided in the hydrologic modeling module under the Tree menu. Once the topologic tree has been constructed the Rational Method dialog can be accessed using the Run Simulation command from the Rational menu.

The Rational Method dialog allows entering all of the necessary values for computing a peak flow for a selected catchment area, or confluence point. The values for $C$, $i$, and $A$ represent the values of the currently selected basin or outlet. Options include:

• Display
  • Type – Options include "Basins" or "Outlets" which will determine the options in the parameters section below.
  • Show – Options include "Selected" or "All". The "Selected" option will on show options for the currently selected outlet or basin. The "All" option will show values for all basins and outlets in the project.
• Units
• Parameters – Section for all values that can be set. Along with the following options, there can be a column for Basin, Outlet, and Unit options depending on how the dialog was reached.
  • Name
  • Runoff Coefficient
  • Rainfall Intensity
  • Compute I – IDF Curves
  • Area
  • Time of Concentration
  • Compute Tc – Basin Data
  • Compute Tc – Map Data
  • Routing Lag Time
  • Compute Lag Time
  • Define Reservoir
  • Flowrate
  • Compute Hydrographs

Related Topics

• Basin Data
• Outlet Data
• Rainfall Intensity
• Rational Method Equation