# 4.16. Input flux of biomass¶

Some species might not do the full life cycle within the simulated domain (reproduce outside the domain for example). For such species, one way to take them into account is to include a flux of schools with user-defined age or length at specific time of the year. This is done by setting either the flux.incoming.byDt.byAge.file.sp# or flux.incoming.byDt.bySize.file.sp# parameters, which are the paths of the CSV files containing the input flux

Table 4.10 Example of input flux by time-step and by age class

Time step / Age

0

2

3

4

0

0

500

800

0

1

0

500

800

0

2

0

400

700

0

3

0

400

700

0

The age classes (year) are automatically scanned by Osmose. In this case there are 4 classes: [0 2[, [2 3[, [3 4[ and [4 lifespan[. Osmose will sets the incoming age at the middle of the interval: 1 year, 2.5 year, 3.5 year, etc. The value of the time step does not matter, Osmose assumes there is one line per time step. The number of time steps in the CSV file must be a multiple of the number of time steps per year. If the time series is shorter than the duration of the simulation, Osmose will loop over it. If the time series is longer than the duration of the simulation, Osmose will ignore the exceeding steps.

In the above example, for the first time step, Osmose will input 500 tonnes of 2.5 year old school and 800 tonnes of 3.5 year school. The incoming biomass should be calibrated. Size classes are handled the same way than age classes.

The simulation.nschool.sp# parameter takes a slightly different meaning for the incoming flux process. It still controls the number of schools created during the reproduction process (which may occur independently of the incoming flux process, depending on your configuration parameters) but it also controls the number of schools created for each age/size class and time step. The meanings are close enough so as not to worry about the value of this parameter and its order of magnitude depending on whether it controls reproduction, incoming flux or both.