Land use type specific conversion settings
Land use type specific conversion settings determine the temporal dynamics of the
simulations. Two sets of parameters are needed to characterize the individual land use
types: conversion elasticities and land use transition sequences. The first parameter set,
the conversion elasticities, is related to the reversibility of land use change. Land use
types with high capital investment will not easily be converted in other uses as long as
there is sufficient demand. Examples are residential locations but also plantations with
permanent crops (e.g., fruit trees). Other land use types easily shift location when the
location becomes more suitable for other land use types. Arable land often makes place
for urban development while expansion of agricultural land occurs at the forest frontier.
An extreme example is shifting cultivation: for this land use system the same location is
mostly not used for periods exceeding two seasons as a consequence of nutrient
depletion of the soil. These differences in behaviour towards conversion can be
approximated by conversion costs. However, costs cannot represent all factors that
influence the decisions towards conversion such as nutrient depletion, esthetical values
etc. Therefore, for each land use type a value needs to be specified that represents the
relative elasticity to change, ranging from 0 (easy conversion) to 1 (irreversible change).
The user should decide on this factor based on expert knowledge or observed behaviour
in the recent past.
The second set of land use type characteristics that needs to be specified are the land
use type specific conversion settings and their temporal characteristics. These settings
are specified in a conversion matrix. This matrix defines:
To what other land use types the present land use type can be converted or not (Figure
3).