Multicriteria Evaluation

Multicriteria evaluation (MCE) refers to a group of analytical methods that fall loosely within the field of multicriteria decision analysis (MCDA). Used within GIS, MCE methods allow individual input map layers used in GIS overlay operations to be weighted such that their relative importance is reflected in the output map. They are used mainly as spatial decision support tools when addressing land suitability/facilities location and evaluation/assessment problems. Example applications might include searching for suitable sites for a wind farm or nuclear waste repository, evaluating the suitability of different locations for growing particular crops, and assessing the likely environmental impact from a new airport development.

MCE approaches are particularly useful when the decision problem being addressed is not tightly defined and involves a wide range of stakeholders and conflicting objectives. Such an analysis requires greater flexibility in the application of input data and problem definition/interpretation than provided by standard overlay methods. MCE methods can, for example, be used to explore the effect of different stakeholder viewpoints regarding a decision for the location of a particular facility on the relative ranking of the alternative locations. In this respect, MCE methods have a number of advantages over standard overlay methods, not least of which is the ability to assign priorities to input layers and utilize the full range of data values they contain.