This example shows the use of a fixed-membership multiple-instance submodel for modelling the movement of water through soil layers. Each instance represents one layer, and has a single compartment, for the amount of water in that layer. The array variable outside the submodel is used to transfer the water flowing out of one layer into the one below it.
The graph shows the behaviour of the model in response to a pulse of rain lasting 8 hours. The top layer responds quickly, followed by the ones below it. The bottom layer has a lower discharge rate.