Sub-Event Properties Dialog

The number of the sub-event

The start date for the event

The start time for the event

This is the time interval between each value. This is constant for each block of data.

The Timestep is entered in the format <n>[<u>], where <n> is an integer greater than zero and <u> is an optional unit specifier (representing seconds, minutes, hours and days respectively), e.g. 10m = 10 minutes.

If <u> is not specified, a unit of seconds is assumed.

This is the rainfall depth in mm that has fallen in the hour immediately prior to the storm. The software uses this figure to calculate how much of the depression storage has been taken up before the storm begins.

Note

The antecedent rainfall depth is read from the first sub-event only.

This is the rate of evaporation in mm/day.

• A local evaporation rate can also be defined for each profile in the profile properties dialog. The local evaporation rate overrides this global evaporation rate value for the sub-event.
• Evaporation rate can vary between sub-events. Different values for evaporation rate can be given for each sub-event in the rainfall event. Different values of local evaporation rate can also be defined for each sub-event in the Profile properties. To use evaporation values specified in second or subsequent sub-events in InfoWorks networks, the Read Subevent UCWI & evaporation check-box must be checked on the Schedule Hydraulic Run Dialog, otherwise only the value from the first sub-event will be used.


Warning

The Read Subevent UCWI & evaporation option is now deprecated on the Schedule Hydraulic Run dialog, but has been retained for backwards compatibility.

Sub-events for evaporation are not recommended to be specified as time varying data. Time-varying evaporation profiles can be set on the Evaporation Data tab of the Rainfall Event Editor.

It is still possible to use the Evaporation field on the sub-event and profile properties for the first sub-event to set a constant evaporation rate for the whole event.

• Evaporation profiles defined in the Evaporation Data Page of the Rainfall Event Editor will override both rainfall sub-event and profile property values.

The antecedent wetness of the catchment for the Wallingford runoff model.

A local UCWI can also be defined for each profile in the Profile Properties dialog. The local UCWI overrides this global UCWI value for the sub-event.

UCWI can vary between sub-events. Different values for UCWI can be given for each sub-event in the rainfall event. Different values of local UCWI can also be defined for each sub-event in the Profile properties.

To use UCWI values specified in second or subsequent sub-events, the Read Subevent UCWI & evaporation check-box must be checked on the Schedule Hydraulic Run Dialog, otherwise only the value from the first sub-event will be used.

Warning

The Read Subevent UCWI & evaporation option is now deprecated on the Schedule Hydraulic Run dialog, but has been retained for backwards compatibility.

Tip

In new networks, intended for use in continuous simulations, a runoff volume model other than the Wallingford one should be selected as the Wallingford runoff model is only intended for single events. The more commonly used runoff models for continuous runoff include Horton, New UK, PDM and UKWIR. See the Runoff Volume Models topic for further information.

API30 for use with the New PR (New UK) runoff model.

API30 can vary between sub-events. Different values for API30 can be given for each sub-event in the rainfall event.

To use API30 values specified in second or subsequent sub-events, the Read Subevent NAPI (New UK Method) check box must be checked on the Schedule Hydraulic Run Dialog, otherwise only the value from the first sub-event will be used.

Note: in order to edit API30 values for individual sub-events, the Allow editing of subevent NAPI option on the Options - General Page must be checked.

Note

The Read Subevent NAPI (New UK Method) option is now deprecated on the Schedule Hydraulic Run dialog, but has been retained for backwards compatibility.

The Soil Moisture Store representing the initial wetness of the catchment for use with the Horton runoff model

The soil (initial) moisture deficit is the fraction difference between the soil porosity and actual moisture content, expressed as a percentage. For use with the Green-Ampt runoff model.

The catchment wetness for use with the SCS, CN and CNSWMM runoff volume models. The default value is 2.

The Wetness index is read from the first sub-event throughout the simulation regardless of the setting of the Read Sub-Event Parameters check-box.

Initial soil moisture content for use with the ReFH runoff model.

Initial baseflow for use with the ReFH runoff model.

Return period in years, for use in Risk Analysis Runs.

Storm duration in minutes, for use in Risk Analysis Runs.

Indicates the way in which the data was created and defines how InfoWorks ICM references the data on results graphs. Valid flags include:

The default value is 0

Required value. The default initial soil saturation.

Required value. The default initial groundwater level.

Whether the initial groundwater level is specified as an absolute value or relative to chamber floor level is determined by the Groundwater Level Type setting.