Note: This is documentation for version 4.3 of Source. For a different version of Source, select the relevant space by using the Spaces menu in the toolbar above

Scenario Options

enario Options allows you to set preferences that affect the selected scenario and are saved with your project. It is accessed via Edit » Scenario Options.

Assurance Rules

Source has a set of Assurance Rules that provide optional checks of models. Assurance Rules define and detect unacceptable states in the model, increasing the confidence that the user can have in the model and the output data. They are useful for troubleshooting and debugging, please refer to Assurance Rules for more information. 

Catchments

Allows the user to define where the runoff enters a link.  There are two options:

  1. Distribute catchment runoff to the downstream end of the link, or
  2. Distribute catchment runoff to the upstream end of each link division (or upstream end of link if there are no divisions)

Default Node Rotation

The default node rotation can be set either by entering an angle between 0 and 359 degrees, or by clicking a compass direction button, where:

  • North to South corresponds to 0 degrees
  • East to West corresponds to 90 degrees
  • South to North corresponds to 180 degrees
  • West to East corresponds to 270 degrees.

Clicking a compass direction button will update the Angle text box with the corresponding angle, and a green tick will show on the chosen button (Figure 1).

Any nodes subsequently added to the schematic editor will have the new default direction. To change existing nodes to the default direction, select the node(s), right click and choose Rotate » Default from the contextual menu. See node rotation for more information.

Figure 1. Scenario Options, Default Node Rotation

Execution Order Rules

 

During a scenario run, components of the scenario are run in a particular order to ensure that they comply with inbuilt Simulation phases and execution order rules. Default execution order is based on leaf node names alphabetically. Thus, renaming a node can change the order. Links are run with their upstream nodes.

Node execution order can be viewed through Execution Order Rules » Execution Order (Figure 2)

Figure 2. Scenario Options Execution Order

The order can be modified by specifying an execution order rule that one node must be executed before another node. This may be needed if you have function dependencies between different branches of a network (Figure 3).

Figure 3. Scenario Options Execution Order Rules


You can record the Flow sequence under Miscellaneous » Flow Sequence » Scenario Flow Sequence

Figure 4. Recording Flow Sequence


Mass Balance

 

Set the Tolerance Limit for the Mass Balance assurance rule.

Node/Link Display Settings

Display configuration for Nodes and Links in the Geographic and Schematic editor can be set by selecting the appropriate Feature options. This allows the default behavior of the Icons and labels associated with the Feature to be displayed or hidden (Figure 5).

Figure 5. Scenario Options, Node/Link Display Options


Ordering Algorithm

This is where you select between using rules based ordering or network linear programming, and configure network linear programming. Please refer to Ordering for more information. 

Performance

Source was originally designed to perform subcatchment calculations in sequence from the top of the catchment to the bottom. Enabling Run Catchments in Parallel (Figure 5) configures Source to perform subcatchment calculations in parallel within a timestep, and then the node-link network is calculated in the normal sequence, from the top of the catchment to the bottom. This will decrease model run times. This option is only suitable for subcatchments where values are not called from other subcatchments within the same timestep. Currently, it is only possible to call subcatchment values either using a function or in catchment model plugins.

Figure 6. Scenario Options, Performance

Orders generated by water users were previously calculated sequentially from the bottom to the top of the system.  As of 3.8.18beta, Process Water User Orders in Parallel is enabled by default, which means that orders are generated simultaneously within a timestep and passed to the supply points. This will decrease model run times. 

In a small number of cases that use continuous accounting, the sequence of water user orders may change the results. If necessary, you can toggle off the option, but most users should be able to use the improved performance option without issue.

Projection

For catchments scenarios, allows you to convert projected layers from the geographic view to latitude and longitudinal coordinates for the map view (Figure 6). Note that the map view is not available in Source (public version).

Figure 7. Scenario Options, Projection.

Rules Based Ordering

The share shortfalls per owner instead of priorities check box, allows you to specify that the shortfalls should be based on the ownership of the water. For example, if all the water in the river is owned by Owner B, then Owner A will be shortfalled first regardless of the relative priorities of the orders. 

Ordering Processing

By default, Source calculates ordering, constraints and off-allocation for every component in the network, regardless of whether it is on a regulated path. You can choose which components will execute by selecting Rules Based Ordering (Figure 8). 

In most cases, using the Auto Select button will select the minimum configuration required for your system. For each component, Auto Select applies the following rules to determine which processes are not required :

  • If there is no storage between the component and an unregulated arm of a confluence (going downstream), do not process constraints;
  • If the component is above the top most storage, do not process ordering or off allocation;
  • If there are no storages downstream from the component (or it is directly above an unregulated confluence arm) and there are no sources of ordering downstream of the component, then turn off all processing; and
  • If there is no regulated confluence arm downstream of the component, do not process constraints.

Performance Improvement

Configuring your scenario to only process ordering, constraints and off allocation for appropriate components will reduce model run time.

Figure 8. Scenario options, Rules Based Ordering.


An example where Auto Select does not currently work well is shown in Figure 8. In this case, choosing Auto Select will turn off all processing because there are no storages. However, ordering should be processed for the Minimum Flow Requirement, the Controlled Splitter, the Inflow and the links between them. In this case, you can set the appropriate configuration manually in Rules Based Ordering. This functionality will be implemented in the future. 

Figure 9. Example where Auto Select for Rules Based Ordering does not work

Ordering Priorities

Priority ordering is a simple and effective system that allows you to specify how shortfalls are prioritised between different demands in Source (Figure 10). It is set at the scenario level and influences how water is taken by water users and released by storages down different outlet paths. It aids in providing information on how water is supplied to users along regulated river reaches between regulating structures. 

 

Figure 10. Scenario Options, Ordering Priorities


At run time, the ordering system feeds back to the nodes how much water is theirs to take. Not all nodes must have a priority, however, it is important to remember that any node not in the priority table, by default receives the lowest priority.

When two or more nodes have the same priority the system will attempt to meet those orders concurrently and distribute any shortfall proportionally.

Note on Priority Ordering at Storages

Some priorities associated with storages exist outside of the priority order reflected in the table. Orders generated based on storage losses automatically are assigned the highest priority. Storage Operating Targets are assigned lowest priority, even when a storage has a higher priority number in the table. If outlet path priorities are set (although this is probably not the case if you are configuring the priority orders table), the outlet path priorities will override the priority order of the lower nodes eg. if an outlet has a priority of 1, even if the orders downstream have lower priority in the table than those downstream from another outlet, the storage will release water to attempt to meet them first.

Re-prioritise Orders

The last column in the ordering priorities table contains checkboxes which, when checked, causes all orders from lower elements of the model to take on the priority specified at the current node as they pass through it. It is only available for the downstream scenario transfer node (full version only) and transfer of ownership node (full version only).

Running Configurations

Running configurations (Figure 11) allow for multiple configurations for each scenario analysis type.

Figure 11. Scenario Options Running Configurations

The configuration option will be available to select in the drop down menu on the simulation toolbar. This option is useful for:

  • flow calibration analysis where you are configuring calibrations to different gauges, and
  • swapping model Time Steps with Scenario input sets, which can now be done seamlessly.

Storages

This section allows you to choose the storage processing method used in the scenario (Figure 12). The Piecewise-linear Integral Method is the default. Selecting the Backward Euler Method enables some functionality. You can configure storage operating levels, and also configure outlet path priorities.  For more information, see Storage node - Storage processing method.

Figure 12. Scenario Options, Storages

Tabular Formatting Settings

This section allows you to define how values should be displayed in the Tabular Editor (Figure 13) used for River Operations. More information about the Tabular Editor can be fund here (Tabular Editor).  Figure 14 shows the settings for Historic values. These configuration options are the same for Historic Override, Forecast and Forecast Override.

Figure 13. Tabular Formatting Settings

Figure 14. Tabular Editor Formatting, Historic



Today

The definition of "today" is the end of the historical period (Today is defined when you click configure on the simulation tool bar after River Operations as been turned on) . The last time-step of the historical period is calculated as the latest time-stamp that is common to all time-series sources in the scenario. You can control the background colour of the cells that are associated with "today" using the Today item.

Cutout

Water takes a finite amount of time to flow through a river system. This lag is represented in the Tabular Editor by discontinuous highlighting. You can control the background colour of the time-associated cells using the Cutout item.

Templates

These allow you to set how particular recorders in the Tabular view are displayed. To Add New Template right click on “Templates” and select “Add New Template” (Figure 15)

You can define the appearance of recordable elements for each type of node. To format a cell, add the required node from the “Node” drop down menu. The recorded elements specific to that node will then be available via the “Recorder” drop down menu. (Figure 16)

To format the items, expand the menu for the template and set the format for the four different options. For each recordable element, you can control:

  1. The colour of the cell background;
  2. The colour of the text in the cell, and whether the text carries a plain or bold-face stylistic variation; and
  3. The display precision (number of decimal places).

In addition, you can define distinctive appearances for elements according to whether the underlying data was obtained from:

  • A time-series source: Historic Data;
  • A value overriding a time-series source: Historic Data (Override);
  • A value calculated by a forecasting algorithm: Forecast Data; and
  • A value overriding a forecast value: Forecast Data (Override)

As different templates can refer to the same recorder, the Template Priority box is used to determine which template should be used. Where a recorder matches two different templates, the template higher in the list will be used.

Figure 15. Tabular Editor Formatting: Templates

Figure 16. Tabular Editor Formatting: Setting formats for different node types and recorders


Wetlands

These options (Figure 17) are the convergence criteria of the algorithm that finds a solution for each wetland within the scenario. They control how long the algorithm spends finding the best match, and how good that match is.

A solution for a wetland on any given timestep will consist of a number of water surface elevations and conveyance flows between wetland nodes. The solution can be said to have a 'precision' related to the estimated mass balance error of the solution - specifically the precision is the root mean square of the mass balance errors in m3.

Figure 17. Scenario Options, Wetlands

Table 1. Wetland configuration options
OptionDefinitionNotes
Maximum IterationsThe algorithm uses an iterative approach and will try to stop after this number of iterations.Generally the algorithm will converge within approximately 5 iterations for most models and timesteps. Certain relastionships can be difficult for the algorithm to solve and a larger number gives a greater likelihood a good solution will be found. It can be a good idea to set a large number of maximum iterations when troubleshooting the wetland components of a model. Iterations will not be used unless the algorithm believes they can improve the result, so there is little harm in a large number.
Maximum Halving Steps

Sometimes the algorithm cannot solve a time step as behaviour changes on a sub time step level. This option tells the algorithm to split the time step in half, and solve each half. This splitting can be repeated until this threshold is reached.

If the algorithm cannot find a good solution for a model, and believes this is because of underlying discontinuities, it will create two half length time steps, solve them and then create a composite solution. If the halved time step still has a discontinuity, this will repeat.

Warning: this number can dramatically increase run time. A large number of time step halving events tends to indicate a problem in the underlying model.

Convergence Limit

The primary criteria for the algorithm to stop iterating. Once the precision of a solution is at or below this threshold it is considered to be 'good enough', and no further iterations will be performed.

The lower this number is, the more precise the answer is, but the longer it will take to run. 1 is often a good compromise.

If the algorithm is producing solutions with precisions above the convergence limit it may represent a problem with the model - or it may mean it is simply necessary to spend some more time calculating an answer. Increase the Maximum Iteration and Maximum Halving Steps until the convergence comes within range. If these numbers are quite large and the precision is still to high it is very likely there is an issue with the numbers in your wetland model.