2.4 CONVERSION ELASTICITY
The conversion elasticity is one of the land use type specific settings that determine the
temporal dynamics of the simulation. The conversion elasticity is related to the
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reversibility of land use changes. Land use types with high capital investment or
irreversible impact on the environment will not easily be converted in other uses as long
as there are land requirements for those land use types. Such land use types are
therefore more ‘static’ than other land use types. Examples of relatively static land use
types are residential areas, but also plantations with permanent crops (e.g., fruit trees).
Other land use types are more easily converted when the location becomes more
suitable for other land use types. Arable land often makes place for urban development
while expansion of agricultural land can occur at the same time 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 of the different land use types can be
approximated by the conversion costs. However, costs cannot represent all factors that
influence the decisions towards conversion such as nutrient depletion, esthetical value
etc. Therefore, in the model we have assigned each land use type a dimensionless
factor that represents the relative elasticity to conversion, ranging from 0 (easy
conversion) to 1 (irreversible change). The user should specify this factor based on
expert knowledge or observed behaviour in the recent past. An extended explanation of
the possible values of the conversion elasticity and how behaviour changes when the
land requirements increase or decrease in time is given below.
0: Means that all changes for that land use type are allowed, independent from
the current land use of a location. This means that a certain land use type can
be removed at one place and allocated at another place at the same time, e.g.
shifting cultivation.
>0...