Methodology

Multi-criteria evaluation (MCE) is a process in which a series of constraints and factors are aggregated to yield a single output map. Constraints are expressed in the form of Boolean logic and serves to limit the areas of consideration, while factors enhance or detracts from the suitability of areas under consideration and is measured on a continuous scale. IDRISI Macro Modeler was used to create the constraints and factors used in the MCE. (Click to enlarge)

MCE uses a concept of soft suitability to standardize factors, whereas constraints use hard boolean logic. Factors are measured on continuous scales, however they are all at different scales. In order for these factors to overlap, all factors must be standarized to a common scale. This is done using IDRISI's FUZZY module. Each factor is standardized using different function shapes, types, and control points.

Factor File	Function Shape	Function Type	Control Points
blowdowndist	Monotonically increasing	Sigmoidal	a = 10 b = 200
lakedist	Symmetric	Linear	a = 10 b = 200 c = 250 d = 500
trailsdist	Monotonically increasing	Sigmoidal	a = 0 b = 50
veterentreedist	Monotonically decreasing	J-shaped	a = 0 b = 1
roadsdist	Monotonically increasing	Sigmoidal	a = 10 b = 150
seadist	Symmetric	Linear	a = 0 b = 75 c = 250 d = 500
streamdist	Symmetric	Linear	a = 0 b = 75 c = 250 d = 500
nestdist	Monotonically increasing	Sigmoidal	a = 250 b = 600