The Rainfall Distribution precipitation type for stormwater projects allows the user to define precipitation data based on the selected rainfall distribution. The data used in this precipitation type are created by historical storm events and statistical analysis for each climate region and then grouped by different durations (6-hr, 12-hr, 24-hr, etc.), quartiles (1st, 2nd, 3rd, 4th), and percent of occurrence (10%, 20%, 30%, etc.).
Follow the steps below to define rainfall distribution data for different CivilGEO software products:
GeoHECHMS
- From the Input ribbon menu, select the Meteorology Data command.
- The Meteorology Data dialog box will be displayed.
- From the Precipitation type dropdown combo box, select the Rainfall Distribution option.
- Select the Precipitation Data option from the Meteorology Specifications dropdown combo box.
- The corresponding panel that defines the rainfall distribution data will be displayed.
Refer to this article in our knowledge base to learn about other precipitation types available in the Meteorology Data command.
GeoSTORM
- From the Input ribbon menu, select the Storm Data command.
- The Storm Data dialog box will be displayed.
- From the Precipitation type dropdown combo box, select the Rainfall Distribution option.
- The corresponding panel that defines the rainfall distribution data will be displayed.
Note that the corresponding panel that defines the rainfall distribution data in the Meteorology Data and Storm Data dialog boxes is identical.
The following sections describe the different options available in the Precipitation Data panel to define rainfall distribution data.
Rainfall Distribution Specifications
This section of the Precipitation Data panel includes the following parameters.
- Rainfall distribution
This read-only field displays information about the type of rainfall distribution selected. Clicking the [Select] button displays the Rainfall Distribution dialog box.
The above dialog box allows the user to select different rainfall distributions available. Refer to this article in our knowledge base to learn more about the Rainfall Distribution dialog box.
- Rainfall description
This read-only field displays the description corresponding to the selected rainfall distribution.
- Storm duration
This read-only field displays the corresponding value of a storm duration (in hours) for the selected rainfall distribution.
Precipitation Assignment
This section of the Precipitation Data panel includes the following input parameters:
- All subbasins same precipitation
After selecting this radio button, the user can assign the same amount of precipitation to all the subbasins present within the model.
- Individual subbasin precipitation
After selecting this radio button, the user can specifically mention the amount of precipitation for all the individual subbasins present within the model.