Time Patterns allow external dry weather flow (DWF) to vary in a periodic fashion. They consist of a set of
adjustment factors applied as multipliers to a baseline DWF flow rate or pollutant concentration. The different types of
time patterns include:
Monthly one multiplier for each month of the year.
Daily one multiplier for each day of the week
Hourly one multiplier for each hour from 12 AM to 11 PM.
Weekend hourly multipliers for weekend days.
Each time pattern must have a unique name and there is no limit on the number of patterns that can be created. Each dry weather inflow (either flow or quality) can have up to four patterns associated with it, one for each type listed above.
Monthly time patterns can also be used to adjust the baseline values of the following hydrological parameters:
- subcatchment depression storage
- subcatchment pervious surface roughness
- soil infiltration recovery rate
The Time Pattern Editor is used to create a new or edit an existing time pattern. The editor contains the following data entry fields:
| Field | Description |
| Name | Enter the name assigned to the time pattern. |
| Type | Select the type of time pattern being specified. |
| Multipliers |
Enter a value for each multiplier. The number and meaning of the multipliers changes with the type of time pattern selected:
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