FEARLUS Model 0-3 Ontology

Model 0-3 is an abstract model of land use change, using strings of binary digits (bitstrings) to represent various properties of the environment. The agents of change are land managers, who use a decision algorithm to choose land uses for the land parcels they own. Land managers may use information from their social neighbours when choosing land uses, in which case, they are referred to as imitative. Transfer of land parcels between land managers is controlled by the land allocation body The model is configured by a number of parameters.

Schedules

Model 0-3 features two schedules, one to use during year 0, that initialises the environment and land managers, and the other to use thereafter.

Initialisation schedule

1. Create the land parcels. The number of land parcels to create is the product of the parameters for the number of horizontal and vertical cells in the environment. Either load the bitstrings from a file, or set each bit to a random value (equal chance of 0 or 1) and clump them for the specified number of cycles. (To be clear, if the bitstrings are loaded from a file, they are not clumped.)
2. Create the land uses. These are either loaded from a file, or created at random. Land uses feature two bitstrings, a "match" bitstring (in which each bit has an equal chance of 0 or 1), and a "don't care" bitstring (in which the probability of 1 is controlled by a model parameter).
3. Determine the climate and economy. The bitstrings for the climate and economy are created, and either loaded from a file, or set at random (each bit having an equal chance of being set to 0 or 1) and then toggled according to the appropriate parameter.
4. Create the land managers. Land managers are assigned to subpopulations, from which they get their decision algorithm.
5. Determine initial land uses. Land managers determine their initial land uses, using the strategy assigned for that purpose. Typically, land uses are chosen at random.
6. Determination of yield. The yield for each land parcel is determined.

Main schedule

This schedule is intended to represent a year. It is repeated either indefinitely, or for a fixed number of years as specified in the parameters.

1. Land managers use their decision algorithm to determine the land use for each land parcel they own.
2. Determine the climate and economy. The bitstrings for the climate and economy are either loaded from a file or flipped using the appropriate bitstring flip probability.
3. Calculation of yield. The yield is calculated as a function of the land use, climate, economy and land parcel physical characteristics.
4. Harvest. Land managers accumulate wealth from the yield of their land parcels, minus the break even threshold.
5. Transfer of land parcels. Land managers with negative wealth must sell their land until their wealth is non-negative. The transfer process is managed by the land allocator.
6. Land managers with no land parcels left are removed from the simulation.
7. Land managers update their neighbourhood weighting according to the number of land parcels they have gained or lost in this year and the neighbourhood weighting update parameter.