The Export Rate model applies a fixed constituent generation rate to a functional unit (FU) to calculate total constituent load. It requires only a single parameter so is quick to use and therefore useful for exploring sensitivity.
Scale
This model is applied at the functional unit scale within a sub-catchment.
The model is a scaling factor and is independent of the basic time-step of the model. It is therefore more appropriate for estimating long term loads.
Principal developer
Cooperative Research Centre for Catchment Hydrology.
Version
Source v2.10
Availability/conditions
Export Rate is automatically installed with Source.
Flow phase
The Export Rate model is a simple area-based scaling factor for constituents from a functional unit. It defines a value between 0 and ∞, representing the physical amount of constituent exported per unit area per year.
For constituent C
| Equation 318 |  |
Input data
A single value representing the export rate in units of tonne/ha/year is required. Area of the FU is taken from the model.
 For export rates: |
Parameters or settings
The parameters for this model are summarised in Table 72.
Output data
Constituent load in kg per time-step.
References
Fletcher, T, Duncan, H, Poelsma, P & Lloyd, L 2004, Stormwater flow and quality, and the effectiveness of non-proprietary stormwater treatment measures - a review & gap analysis, Technical Report 04/8, Cooperative Research Centre for Catchment Hydrology.
Table 72. Model parameters
Parameter | Description | Units | Default Min | Default Max |
|---|---|---|---|---|
exportRate | Fixed rate of export of a constituent from a land use | tonne/ha/year | 0 | ∞ |