Use this tag when referring to spatial clustering in GIS.

Spatial clustering, which groups similar spatial objects into classes, is an important component of spatial data mining (Han & Kamber, 2000). Spatial clustering can be used in the identification of areas of similar land usage in an earth observation database or in merging regions with similar weather patterns

http://dusk.geo.orst.edu/ucgis/web/oregon/papers/lu.htm