Using local saturation

Load the model “simulate_deforestation_using_local_saturation.xml” from \Examples\advanced\local_saturation Local saturation prevents a change from occurring within a specific region, in which a class area is greater than an established threshold (figure bellow). This feature is useful to simulate diffusion process as well as to establish a minimum forest remaining area (as established by the Brazilian forest code for private properties). Local saturation can be implemented by reducing the probability of a transition using an asymptotic function as follows:

P2 = P1 * (Li – Oc) / (Li + Oc), case Li >= Oc
P2 = 0, case Li < Oc

where P2 is the new probability, P1 is the original probability, Li is the maximum number of cells of a particular class that is allowed to occur within a certain map neighborhood and Oc is the number of cells of that class within that neighborhood. In this example, deforestation must stop in a local region (in this case a window size of 59.25 hectares or 9 cells - 3×3 window) when 50% of this region is deforested. For each model step, the amount of deforested cells is calculated in every 3×3 window of the landscape map. In this case, the threshold consists of five cells as follows: