Losses in a river system can be represented in several ways. Some losses, such as reach evaporation, loss to groundwater and filling of dead storage can be simulated through a link. The loss node can be used to represent losses which are not captured by such explicit models. In Source, the loss node allows you to define a relationship between river flow and loss rate.
A piecewise linear function can be entered by hand or loaded from a .CSV file (format shown in Table 4). It is advised that you enter a flow rate relationship greater than the likely maximum simulated flow. If you do not, the linear relationship derived from the last two rows of the loss table will be used to calculate any projections. Refer to About piecewise linear editors for more information.
Ownership can also be configured at the loss node. You can specify what proportion each owner in the system will lose. Refer to Loss.
Table 4. Loss node (data file format)
Row
Column (comma-separated)
1
2
1
Inflow (ML/d)
The loss node describes the amount of water that is lost from a point in the stream network. Losses may include physical processes such as transmission losses due to evaporation and seepage, or may be used to represent losses associated with measurement error in the data used to develop the model, such as flow-measurement uncertainty.
Scale
Losses are implemented at the site-scale.
Principal developer
eWater CRC
Scientific Provenance
Gauge node was introduced in RiverManager and subsequently became part of River Manager, Source Rivers, WaterCAST, Source Catchments and Source.
Version
Source version 3.0.1
Dependencies
The loss node must be part of a node link network.
Availability
Loss is automatically installed with Source.
Structure & processes
A loss is specified relative to the flow at that point in the system using a monotonically increasing piecewise linear function.
Input data
The input data for the Loss model is a relationship between inflow and loss from a point in the network. The data entered into the table or configured in a .csv file must be in increasing order and the increase in loss must be less then the increase in inflow.
Parameters or settings
Model parameters are summarised in Table 23.
Output data
The loss node outputs a time series of flow.
Table 23. File format for a piecewise linear function configured as a .CSV file
Row | Column 1 | Column 2 |
|---|---|---|
1 | "Inflow (ML/d)" | "Loss (ML/d)" |
2 | 0 | 0 |
3..n | inflow | loss |
loss is the loss in megalitres per day corresponding with the associated level of inflow.
numeric value | numeric value |