Pollutograph (InfoWorks)


A Pollutograph defines a set of water quality inputs to the system. The Pollutograph defines concentrations for sediment fractions and dissolved determinants, and the potency of attached determinants. The input is applied at a particular node, link, 2D point source, 2D line source or 2D boundary using the Profile Properties Dialog.

The Pollutograph is used in conjunction with an Inflow or Level event. The Inflow or Level event provides flow measurement and the two together define actual pollutant inflow. For every point that has a determinant input defined in the Pollutograph a hydrograph must also be defined in the Inflow or Level event.


Pollutograph events cannot be used in simulations in conjunction with Time Series Database objects.

To use a pollutograph in a simulation, just include the pollutograph in the Pollutograph box on the Schedule Hydraulic Run View.


Remember that volume inflow data must be present for each water quality determinant input. An Inflow and/or a Level event must be included in the run. There must be a hydrograph for each object that has a determinant input in the Pollutograph. If there is no volume inflow data the determinant input at that point is ignored.

Pollutograph components

Pollutographs are viewed and edited in a version of the Event Editor. A number of tabs are displayed in the editor, each tab representing a different determinant inflow.

There are several categories of determinant input:

Sediment input

The two sediment tabs (SF1 and SF2) define time varying sediment concentration.

Dissolved pollutant input

The dissolved pollutant tabs (BOD, COD, NHD, TKD, TPD, P1D to P4D, DO, NO2, NO3, PH, SAL, TW, COL, ALD, SI and C1D to C4D) define time varying concentrations for dissolved determinants.

You can also define fixed potency factors for determinants attached to sediment fractions if applicable. If you define time varying potency on the attached determinant tabs for the same location and sediment fraction, then the fixed values set here are ignored.

Attached pollutant potency

The attached determinant tabs (BOA, COA, TKA, TPA, P1A to P4A, ALA, and C1A to C4A,) define time varying potency factors for attached determinants.

The time varying potency factors override any fixed potency factor that may be defined on the dissolved determinant tab.

Detrital pollutant input

The detrital determinant tabs (DC, DN, DP and DSI) define time varying concentrations for detrital determinants.

(Detrital determinants are used in the calculation of growth and decay of Algae and Macrophytes).

Each determinant is defined independently. See Water Quality Determinants for further details of the determinants that can be modelled.

Sub-Events and Profiles

Pollutograph events, like many other types of event, are divided into:

For more details on how InfoWorks ICM deals with sub-events and profiles, see the main Events topic.

Each determinant type is treated separately when carrying out simulations. A different number of sub-events, with different start and end times can be defined for each determinant type.

Each determinant type can have more than one profile. For sediment fractions and dissolved determinants there is a maximum of one profile per input node per determinant type. Attached determinants can be attached to either or both of the sediment fractions. There can be two profiles per node for each attached determinant - one for each sediment fraction.


Event Editor