To Add and Modify Distribution Based Rainfall

Add variable Distribution Based Rainfall data to test and analyze a drainage system. Distribution Based Rainfall defines sets of rainfall events based on rainfall distributions (temporal patterns), durations, and rainfall depths.

1. In the Analysis Criteria workspace, click Open Rainfall Manager.

2. In the Rainfall Manager, click the Distribution Based Rainfall tile. The Distribution Based Rainfall Creation editor opens.

   

3. In the Name field, enter a unique name for the rainfall set.

To Create Distribution Based Rainfall Events in a Set

Distribution Based Rainfall defines sets of rainfall events based on rainfall distributions (temporal patterns), durations, and rainfall depths. Multiple distribution based rainfall events can be created in a distribution based rainfall set. Rainfall distributions, including pre-defined distributions (like those used for SCS rainfall), and custom distributions defined by users, are available to all distribution based rainfall sets within the rainfall library.

1. In the Distribution Based Rainfall Creation workspace, click Add Rainfall Event to begin creating events for the rainfall set. The Adding Rainfall Event editor displays.

2. In the Name field, enter a unique name for the rainfall event.

3. Select a distribution type from the Distribution menu. There are 4 synthetic temporal pattern rainfall distribution curves available from the Soil Conservation Service (SCS): SCS Type I, SCS Type IA, SCS Type II, or SCS Type III.

4. Enter a Rainfall Depth for the rainfall distribution Duration.

5. (Optional) Adjust the Run time for the rainfall distribution. The default is twice its preconfigured Duration.

6. The data is then presented in a table and a hyetograph.

   

   The table and hyetograph can display either Depth or Intensity data. Data displays using the units defined in the source drawing.

   Note: there must be at least 2 entries containing the minute increment and its coinciding rain depth in inches (or millimeters depending on drawing units).

7. Click Add Rainfall Event to add the event to the Distribution Based Rainfall set. The Distribution Based Rainfall Creation editor displays showing the updated Rainfall Events List.

   

8. Click Create Rainfall to save the Distribution Based Rainfall set. The Rainfall List displays the new rainfall set.

To Modify Distribution Based Rainfall Sets

1. In the Distribution Based Rainfall List, select the set to be modified. The Distribution Based Rainfall editor displays.
2. Rename the set or add additional Rainfall Events.
3. Modify Distribution Based Rainfall events.
4. Click Save Changes.

To Modify Distribution Based Rainfall Events in a Set

1. In the Distribution Based Rainfall List, select the set containing the event to be modified. The Distribution Based Rainfall editor displays.

   Tip: In the Rainfall Events table, it is possible to modify the following:
   • Click into cells to manually change Names, Distributions, Rainfall Depths, and Run Times.
   • Delete a Rainfall Event by clicking > Delete.

2. In the Name column, click Open Rainfall Event or click > Open. The Rainfall Event Editor opens. The following modification options are available.

   • Rename the event.
   • Change the rainfall Distribution type.
   • Change the Rainfall Depth.
   • Change the Run time for the Rainfall Event.

3. Click Save Changes.