A Gauge node either represents a physical recording device that measures river levels at a point in a river or a logical point in a river model where you can record and view the modelled flow. Gauge nodes are used in conjunction with rating curves to estimate flows for a particular location. You can use a gauge node for model calibration and verification, by comparing observed and predicted flow.
Figure 1. Gauge node
The Bureau of Meteorology (BOM) station identifier can be set from the station list visible in Figure 1. Find and select the station name in the list and click OK.
The Use Inbuilt Station checkbox is enabled by default and ensures that an Australian based gauge is used. You can disable this checkbox to use a non-Australian based gauge.
If you have a time series for the physical gauge location, you can load it by clicking the file in Data Sources. This populates the chart on the right hand side with the time series. Table 2 shows the file format. However, this data is for your own reference only. It plays no part in the model run.
Table 1. Gauge node (data file format)
| Row | Column (comma-separated) | |
|---|---|---|
| 1 | 2 | |
| 1 | date | value |
Rating Curves
A rating curve converts a flow into a level, producing an output of level. You would often have recorded gauge level at a gauge rather than flow, thus making it useful for calibration.
Observed flow and unaccounted difference
This is where you input observed flow by entering a value, supplying a time series or defining a function (Figure 2). Enabling the Set Flow checkbox results in the modelled flow at a gauge being overridden by the gauge flow (Figure 2). This forces the modelled flow to equal observed flow and converts a gauge node to an Unaccounted Difference unaccounted difference node (Figure 3). This is used in operations environments to check for differences in water balances on links. Refer to Forecasting for details.
Figure 2. Gauge node, Observed flow
Figure 3. Gauge node, unaccounted difference
A rating curve converts a flow into a level, producing an output of level. You would often have recorded gauge level at a gauge rather than flow, thus making it useful for calibration.
Ownership – Refer to Ownership for more Ownership
Refer to Ownership for more information. Operations – this
Operations
This is similar to the recession forecast model in the inflow node. Refer to to Forecasting inflows.
Constituents
–This behaves in a similar manner as Gauge flow. Refer to to Constituents - Gauge. Ensure that constituents and constituent sources have been defined prior to configuring them (using using Edit » Constituents).