Note: This is documentation for version 5.20 of Source. For a different version of Source, select the relevant space by using the Spaces menu in the toolbar above
Weirs
gure 1. Weir, Upstream Reach
Specifying operating targets
Under Operating Targets, both Minimum operating level and Maximum operating level are only used when the storage is configured as a weir. The storage will not release water to satisfy downstream requirements if this results in the water level dropping below the minimum operating level. Likewise, water will be released to prevent the storage rising above the maximum operating level.
Gauged Level and Releases
As for storages, it is possible to overwrite modelled data with observed data in a weir using either Gauged Level and/or Gauged Releases. When you do so, the weir icon changes to indicate this (Figure 2). See Gauged Level and Gauged Releases for more information.
Figure 2. Weir, observed data replaces modelled data
Configuring ordering
When configuring ordering for a weir, refer to Ordering at storages.
Weirs and constituents
Weirs only currently work with marker constituent routing and does not yet work for Lump constituent routing.
Flow processing options in weirs
In the previous versions of Source, only 'Piecewise-linear Integral Method' was available as an option for flow processing and storage volume calculation in weirs . In the new version from 5.13 beta, 'Backwards Euler' Release Manager for Weir Node Models is also available from Edit > Scenario Options> Storages. As in Figure 3, the user can select either Backward Euler Method or Piecewise-linear Integral Method for weirs. As in Storages, Backwards Euler is the default method for weirs.
Figure 3. Scenario Options showing weir options
Selecting Backward Euler Method enables some functionality. You can configure storage operating constraints, and also configure outlet path priorities as in Storage nodes. When this method is selected:
- the use of operating constraints will become optional
- each outlet path will have an option to enable releases associated with operating constraints
- a safe release volume will be specifiable
In the previous versions, the option for operating constraints was forced ON for weir node as it had only Piecewise-linear Integral Method. Similarly, safe release options were not visible in the previous versions.