CLEM Events

CLEM.CLEMEvents

This component handles the timing and triggering of the CLEM specific events and is associated with the APSIM Clock component.

CLEM simulations require a series of specific Events to be fired in a specific order to ensure tasks and actions are performed correctly in each time-step. In the initial release of CLEM this task was delegated to the APSIM Clock. While effective, this added all CLEM events to the APSIM Clock properties which was confusing for other APSIM users. By assigning the management of CLEM events to the CLEM Events component we resolved this issue while also providing a central location for all timing related properties.

The development of the CLEM Events component also provided the opportunity to consider time-steps finer than the default monthly step originally offered. This change was requested by researchers simulating ruminant growth in feed lots and was always thought to be a useful future improvement to the model.

Work is ongoing to allow CLEM to operate down to the daily time-step used by other APSIM models. This functionality has required a complete redesign and implementation of a number of aspects core to the initial model development. For example, tracking age in months is not suitable for sub-monthly time-steps and so equations have been modified and the timing of many actions are now stored as date stamps with time since the event reported in days. Also, providing user control to specify the timing of events while undertaking a custom time-step requires a rethink of CLEM processes such as the functionality of timers and assisting the user in working with a range of intervals to define the year and simulation.

The following parameters are used to define this component

This property defines the time-step on which the CLEM simulation will run. It is a drop down list of options with a Custom setting allowing the user to define a custom interval.

Careful consideration needs to be made to selecting the simulation time-step as this can add significant CPU and memory overhead when running herds with a large number of individuals. The time-step will also influence the rate of data being reported and increase the size of resulting database files. It may also be difficult to both specify the timing and undertake some activities , while other activities might take grater than the duration of the time-step which has not been implemented.

Non-monthly time-steps will become out of sync with the months of the year.

This represent the default time-step used by the initial release of CLEM. The monthly time-step is considered useful for running whole-farm simulations and allocating labour in areas where detailed data is not available.

Representing double the frequency of the original monthly time-step a fortnightly time-step may provide finer control over managing herds and crops without imposing simulation time and data handling increases.

This represents a weekly time step of 7 days.

This is the smallest time-step and runs the CLEM simulation at the same rate as all other APSIM models.

This option allows the user to define the time-step to be applied. The length of the time-step (in days) is specified in the following property which will only be visible when this option is selected.

Only a selection of CLEM components currently support a time-step other than Monthly. An error will be thrown when these components are used in simulations with a finer time-step specified. Components will have the ability to run at smaller time-steps as updated and checked and issues such as specifying timing in an intuitive fashion are solved.

The length of the time-step interval to use in days. This property is only available when Time-step is set to Custom.

The following parameters define the reporting and calculation of ecological indicators

CLEM will track a range of ecological indicators during the management of pasture (advanced). This parameter is used to define the interval at which these calculations are performed and reported. The default is annual (value of 12) with the month of reporting specified in the property below.

This property is only needed when implementing the Advanced version of Managing pasture but must be set for all simulations. New CLEM components will have a default value of 12.

> 0

CLEM will track a range of ecological indicators during the management of pasture (advanced). This parameter is used to define the end of the first month in which these calculations are performed and reported. The default is July (value of 7) to represent Australian (southern hemisphere), summer pasture growth. The interval of calculation is specified in the property above.

This property is only needed when implementing the Advanced version of Managing pasture

Jan - Dec

The following components are required to set up this component

The APSIM Clock is a required component of any simulation and determines the start and end date of the simulation.

This CLEM Eventscomponent needs to be provided as a child component of the APSIM Clock.