Grid Reports

Return period analysis reports use cumulative flooding onto 2D zone rather than cumulative flow from 2D zone when calculating flood volume at 2D nodes (i.e. nodes whose flood type is 2D, gully 2D or inlet 2D). This means that flows from the surface into the node are not subtracted from the flows from the node onto the surface when the flood volume for the analysis is calculated.

In order to produce a Return Period Analysis report a series of simulations using rainfall of different known return periods must be carried out.

Ideally you would carry out a series of simulations using design rainfall events where the rainfall event was the only variation. Choose a series of return periods for each of a series of storm durations. For example, return periods of 1, 2, 5, 10, 20 and 50 years with durations of 15, 30, 60 and 120 minutes would be a total of 24 simulations. A maximum return period of 200 years can be used with the UK Rainfall Generator.

All the simulations must use the same network.

Using observed rainfall

In most cases you will use design rainfall events. You can however use observed rainfall as long as return period and duration information is available from the rainfall event.

InfoWorks ICM will look for return period and duration values in the rainfall event in the following order:

• Return period and Storm duration fields in the Sub-event properties of the first sub-event
• Profile title field in the Profile properties of the first profile

When using the profile title, the return period and duration of the storm should be formatted as:

5 yr 60 min

where 5 yr is the return period in years and 60 min is the storm duration in minutes. To designate a return period of less than one year a negative number can be used. For example -2 yr would mean a six month return period.

Displaying an RPA report

To display an RPA report:

1. Select Grid report | Return period analysis report from the Results menu. The Return Period Analysis Grid Report dialog is displayed.
2. From the Explorer Window, drag the simulations in which you are interested into the Simulations box of the report dialog.
3. Choose the maximum return period in which you are interested. InfoWorks ICM will display an x in the RPA field of the grid if surcharge or flooding has occurred due to a storm with return period greater than this maximum, or if the return period at which flooding occurred can not be determined from the selected simulations.
4. Click the Produce Grid button.

The RPA Report View is displayed.

A grid report is created that displays flood volumes for each node for one or more simulations. For 2D nodes, the cumulative flooding onto a 2D zone, rather than the flood volume, will be displayed.

There will be a separate Flood/Lost Volume column for each simulation included in the report.

To display a Flood Volume Report:

1. Select Grid report | Flood volume report from the Results menu. The Flood Volume Report dialog is displayed.
2. From the Explorer Window, drag the simulations in which you are interested into the Simulations box of the report dialog.
3. Click the Produce Grid button.

The Flood Volume Report View is displayed.

The Worst Case Report allows you to compare a number of simulations and display the worst case for one of a number of node or conduit parameters.

The Worst Case options for InfoWorks simulations are:

• Node - Flood Depth, Flood Volume or Level. For 2D nodes, cumulative flooding onto 2D zones, rather than Flood Volume, will be displayed.
• Conduit - Downstream Flow or Upstream Flow

The Worst Case options for SWMM simulations are:

• Node -Depth, Head or Total Inflow
• Conduit - Capacity, Flow or Velocity

When displaying the worst case for a node or conduit, ICM also displays the summary results for that node or conduit from the simulation that produced the worst case.

In order to produce a Worst Case Report you will first need to carry out a series of simulations using different rainfall events.

The report will display return period and duration values, if the information is available from the rainfall event. When using observed rainfall, ICM will look for return period and duration values in the rainfall event in the following order:

• Return period and Storm duration fields in the Sub-event properties of the first sub-event
• Profile title field in the Profile properties of the first profile

When using the profile title, the return period and duration of the storm should be formatted as:

5 yr 60 min

where 5 yr is the return period in years and 60 min is the storm duration in minutes. To designate a return period of less than one year a negative number can be used. For example -2 yr would mean a six month return period.

All the InfoWorks simulations must use the same InfoWorks network, and all the SWMM simulations must use the same SWMM network.

To display a Worst Case Report:

1. Select Grid report | Worst case report from the Results menu. The Worst Case Grid Report dialog is displayed.
2. From the Explorer Window, drag either the InfoWorks or SWMM simulations in which you are interested into the Sim/SWMM sim box in the report dialog.
3. Select the object type and parameter to be displayed in the report.
4. Click the Produce Grid button.

The Worst Case Report View is displayed.

The Velocity Profile Report provides a detailed breakdown of flow, bulk velocity and wetted area for a selection of river reaches. Values are provided at each timestep for each river reach section as a whole and for individual panels that make up the sections.

Values may be displayed in a grid view or exported to csv files.

To display a Velocity Profile Report:

1. Select Grid report | Velocity profile report from the Results menu. The Velocity Profile Grid Report dialog is displayed.
2. From the Explorer Window, drag the simulations in which you are interested into the Sim box of the report dialog.
3. Optionally specify a Selection list
4. Select the Report format to be used
5. Click the Produce Grid button to display the Velocity Profile Report View or the Export to CSV button to export the results to csv format.