Water Quality Age Profile page

The page is displayed by clicking the Water Quality Age Profile tab on the property sheet for a simple node, reservoir, transfer node, fixed head, well, and hydrant that has control data added.

For more information on all node types, see Nodes. For more general information on controls, see Control Data.

There are two ways to set up the water quality age for a node:

• Use the Water Quality Age field to set an age of water value that is applied at the start of the simulation.
• Use the grid to enter a series of variable age of water for each timestep for the simulation.

Note: If both an initial age of water and a series of time dependent age of water values have been entered, the time dependent age of water values take precedence.

By default no interpolation is used between data points. Each concentration value entered in the grid is maintained until the next date / time entry, or until the end of the simulation. Check the Linear Age Profile box for linear interpolation to be used between data points.

The following options are available for extending the profile outside of the entered dates / times:

Data field	Description
Linear Age Profile	This checkbox decides if values in the profile grid are interpolated. Checked - Linear interpolation is carried out between values Unchecked - The value entered in the grid changes at each time point, and is maintained until the next time point is reached.
Before First Point	Option Description Extend Back The first value in the grid is extended back to the start of the simulation (and to the start of the repeat period for repeated profiles). Extrapolate Back Applies to Linear Profiles only: the first two values in the grid are used to extrapolate back to the start of the simulation (and to the start of the repeat period for repeated profiles). Note: If Extrapolate Back is selected for a non linear profile, the profile will be extended back. Zero/Unchanged A value of zero or "off" is applied from the start of the simulation until the date / time of the first value in the grid (and from the start of the repeat period for repeated profiles).
After Last Point	Option Description Extend Forward The last value in the grid is extended to the end of the simulation or the end of the repeat period. Extrapolate Forward Applies to Linear Profiles only: the last two values in the grid are used to extrapolate forward to the end of the simulation or the end of the repeat period. Note: If Extrapolate Back is selected for a non linear profile, the profile will be extended forward.
Repeat Profile checkbox	If checked, repeats a profile (from 00:00 for the selected Repeat Period) for the duration of the simulation. Important: When using the Repeat Profile option, if the defined profile spans over the selected repeat period, the profile will not be repeated.
Repeat Period	Profile period which will be repeated throughout simulation, if the Repeat Profile box is checked.