Building the Fish Banks Model and Renewable Resource Depletion

22
3.3.2 Building the Model
? Create the FISH and SHIPS stocks.
? Create Total Catch per Year as an outflow to the FISH stock.
? Create the following converters:
Area = 100 (square miles)
Density = FISH / Area
Catch per Ship (Leave undefined)
? Define the flow Total Catch per Year:
Total Catch per Year = SHIPS * Catch per Ship
? Set the initial value of FISH (1000 fish) and SHIPS (10 ships).
? Connect Density to Catch per Ship.
? Double-click on Catch per Ship.
? Select Density from the Allowable list.
D-4543-2
? Click once on Become Graph, then enter the proper ranges, Inputs and
Outputs as shown in Figure 10.
? Click on OK.
Make sure that your model is correct by comparing with Figure 11. If your model
is structurally the same, then go on to the next section. If not, please refer to Appendix 4
and correct your model.