Generate a Storm Event Group (SEG)

With the Storm Event Finder, you only need to set search conditions once to create a storm event group for every rainfall site in your project. The tool will automatically list relevant rainstorms for each site, including details such as when it rained and how much rain fell within a given time-period. Additionally, you have the option to manually add storm events to an SEG.

1. Open the SEG Finder

Starting from the Main Project page, click Create Storm Event Groups.
The Create Storm Event page opens.

2. Enter a Start Date and End Date

Alternatively, you can enter a Start Date and the number of following days (+days). The end date is automatically determined.


3. Configure the Event Occurs Condition

This search condition defines the minimum requirements for a rain event to be included in the search. It can be based on either accumulation or intensity.


4. Configure the Event Start Condition

This search condition defines the minimum requirements for marking the start of a storm event. It can be based on either accumulation or intensity. The tool will search for storms that meet this criterion, within those rainstorms that meet the Event Occurs Condition. Each result will will mark the 'start' of a storm event for the SEG.



5. Configure the Event End Condition

This search condition defines the end of a storm event. It can be based on either accumulation or intensity. For each Event Start, the system will find a corresponding Event End based on the parameters in this section.


6. Configure Site Specific Details

  1. Enter a Storm Event Group Set Name.
    This is the name that the SEG set will be saved as.
  2. Use the check-boxes under Create to select the rainfall sites you want to include in the SEG set.
    The system will make one SEG for each site.
  3. For each site you've selected, choose a rainfall channel within which you want to conduct a search for storm events.

7. Click Create Storm Event

The system searches for storm events within your chosen sites, based on the configured search criteria. The results populate on a subsequent page.


8. (Optional) Enter a Storm Event Group Name

By default, each SEG in the set will be given the default 'Storm Event Group Set Name' you defined earlier. However, if you have more than one SEG in a set, each pattern will save individually with the same name. For this reason, you may want to modify the Storm Event Group Name to something unique for each Group in the set.


9. Review the SEG

  • Duration is the end date minus the start date in days, hours, and minutes.
  • Total accumulated rainfall detected is a summation of rainfall recorded between the corresponding start date and end date.
  • The left side of the table uses IDF data to indicate the historical significance of the storm event. Any empty regions imply that the event fell below the threshold.

10. (Optional) Remove storm events from the Group

Locate the list item you want to delete and click Remove.


11. (Optional) Manually add storm events to the Group

You will need to know the exact date and time of the storm event you want to add. One approach is to use FlowWorks' Graphing tool to plot the channel's data and gather the necessary information.

  1. Click Add Storm Event.
    A new list entry appears.
  2. Input dates and times in the Start Date and End Date fields (expressed in 24-hour time).
  3. Click Fetch Data. The system adds Total Accumulated Rainfall Detected to the list and adds the event to this group.

12. Save the SEG

  • If you chose just one rainfall site, click Save Storm Event.
    The Project Dashboard page loads, where your saved SEG is now available for review/editing.
  • If you chose >1 rainfall site, click Save and Next. The SEG for the following site appears.
    Repeat steps 8 through 12.
    Once you are finished saving the final SEG in the set, you are taken back to the Project Dashboard page.

From the Rainfall Sites list, you can see how many SEGs have been created for each rainfall site. In the SEG finder, we created 2 SEGs for the rainfall site. You can see all the SEGs that have been made for each of the rainfall sites in a project by selecting the rainfall sites from the list.


Next Step

The next stage in I&I setup entails reviewing your RDII Charts and generating a Correlation Graph.
As well, to find out how you can modify and/or delete SEGS, refer to the Manage Storm Event Groups (SEG) documentation.

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