Page Comparison

The main function of the environmental flow manager is to prioritise and activate actions based on a priority purchasing style conceptual model (Figure 3).

...

Figure 3. Expanded Environmental Flow Manager Conceptual Model: Detailed flowchart for the 'Prioritise and activate/flag actions' box in Figure 2.

Environmental Flow Manager Priorisation Phase:

After the resource assessment phase is complete, the flow manager phase begins. At a high level the process is as follows:

1. Update functions with time of evaluation of Environmental Flow Prioritisation
2. Decide if the flow manager will run based on the decision point configuration
3. Calculate Portfolio balances
4. Run the main prioritisation loop

1. Update functions with time of evaluation of Environmental Flow Prioritisation

All functions are updated at the very start of the prioritisation phase. This is to ensure that any priority, estimated cost, balance adjustment and decision point functions can get updated before we begin the main section of the EFM prioritisation phase.

2. Decide if the flow manager will run based on the decision point configuration

The decision point can be used to restrict how often the prioritisation loop occurs. This can be set to every time step or a boolean function. If a function is used it must be set to a time of evaluation of Environmental Flow Prioritisation or earlier.

If a function returns false, each group maintains the state it set to by the EFM during the last time the main priorisation loop occurred (i.e. any enabled groups will continue being enabled, even though the EFM has not run).

3. Calculate Portfolio balances

The balance of a portfolio is equal to:

Balance = Sum(Account.Balance + Balance Adjustment) for accounts with non-zero share.

There is also the concept of Availabe Water, this will be used in the main prioritisation loop to keep track of any addition

4. Run the main prioritisation loop

Before any prioritisation can occur, the priorities of all actions associated with EFM are calculated. Only actions that are enabled at the node and are allowed to order are considered by the EFM.

The priority of a action is defined as:

Priority = (1-Condition) x Importance

where Condition unless specified by the user is equal to

Condition = EXP(- time since last successful spell/average return interval)

The Priority of a group is the highest priority of

The priorities are only calculated once per timestep. This means any changes to condition or importance during prioritisation iterations will not be used.

Groups to Prioritise = Groups with at least one action (that is enabled or allowed to order)

Next, Addition groups are removed from Groups to Prioritise:

foreach (group in Groups To Prioritise):
  if group.IsActivelyDelivering:
    group.EnabledByEFM = true
    CommitEstimatedCostToPortfolios(group)
    Groups To Prioritise.Remove(group)

CommitEstimatedCostToPortfolios will distribute the estimated cost of a group across portfolios so that the Portfolio.AvailableWater is reduced. This distribution works in a similar way to distribution of water user orders to supply points. That is, the cost will be split across the highest priority portfolios first in the share percentages specified in the portfolio configuration. Lower priority portfolios will only be used once higher priority portfolios have no available water.

Once the prioritise are calculated, the main loop begins:

// sort groups by whether they were enabled by the EFM first, then by priority 
SortGroups(Groups to Prioritise)
while (Groups to Prioritise.Count != 0):
  UpdateFunctions()
  group = Groups To Prioritise[0]
  // TotalPortfolioAvailableWater is the sum of all of the group's portfolios AvailableWater.
  if (group.IsInSeason && group.TotalPortfoliosAvailableWater >= group.EstimatedCost):
    group.EnableByEFM = true
    CommitEstimatedCostToPortfolios(group)
  else
    group.EnableByEFM = false

  Groups To Prioritise.Remove(group)
   

It is important to note a few things in the above psuedo code. First, groups that were enabled the last time the EFM was run will be prioritised before other groups that were not, regardless of priority. Secondly, if a group has no actions that are in season today, they will always be disabled. The ReducePortfoliosByCost function is the same as described above.

The UpdateFunctions() method will update any functions with time of evaluation Environmental Flow Prioritisation. Note: Any modelled variables that need to be used during the iterations must have the Date Range set to Current Iteration otherwise they will not update each iteration.

Prioritisation of actions/groups within the flow manager

The environmental flow manager sorts groups of actions into ascending priority order by examining the priority values generated for each action by the importance and condition functions.

...

If groups have the same priority value, then they are ranked by the importance values, then by conditionby the condition. The priority of a group is considered to be equal to that of the highest priority action within that group. 

...

The default condition calculation if not specified by the user is EXP(- time since last successful spell/average return interval)

Environmental Flow PrioritsationPrioritisation Phase

All functions are set by default to evaluate at the start of time step, environmental flow prioritisation phase is an advanced usage. If enabling one group has dependencies on another, the functions will need to be evaluated multiple times during prioritisation, and therefore the time of evaluation in the Environmental Flow Prioritisation phase is indicated. This allows the cost of actions, and hence groups, to be recalculated based on the groups which have already been enabled or disabled. This recalculation occurs each time a group is enabled or disabled.

...

An action will effectively be disabled if the flow manager does not allocate water to its group, however, the action will still monitor the flow based on action definition. 

...