Boolean algebra is a type of mathematics that does not deal with
numbers but with truth conditions ("true" / "false"). Instead of the basic arithmetic operations,
Boolean algebra handles operations that link two truth conditions as input values together and
result in another condition of truth. The most important operators are AND (intersection), OR (union),
XOR (exclusive union), and NOT (negation).
Boolean Overlay:
The Boolean Overlay is an intersection of binary coded data layer
using the Boolean operators AND, OR, XOR, and NOT. The result of a Boolean Overlay is again a data
layer with areas that are true and areas that are false.
Decision support with GIS:
Decision support in GIS is a system based on the suitability
analysis to support decision-makers on issues of spatial and environmental planning. Spatial models
and scenarios are used to assess different land use types. For multiple selection criteria and only
one objective, a multi-criteria evaluation (MCE) is used. In the more complex case of multiple,
possibly even exclusionary objectives, the different land uses need to be weighed (multiple-objective
evaluation, MOE).
Standardization:
Standardization with weighted overlay is defined as the translation of
the heterogeneous input data into a uniform scale for all layers (e.g. 0-1, 0-100, 0-255).
Suitability analysis:
Suitability analysis is an evaluation of the suitability of
a location or area for a certain use. Suitability analysis is usually done through an intersection
of social, ecological, economic, physical, biological or other criteria. Suitability maps are
usually the result of a suitability analysis. They display the spatial distribution of the determined
values in a graphical form.
Weighted overlay:
Weighted overlay is an intersection of standardized and differently
weighted layers in a suitability analysis. The weights quantify the relative importance of the suitability
criteria considered.