regionsboth

regionsboth is a term used in geographic information systems (GIS) and data science to denote the set of geographic regions that satisfy two concurrent criteria, effectively the intersection of two region collections. The term is common in workflows that require identifying areas meeting multiple conditions, such as regions within a country that fall within a biodiversity hotspot or administrative regions that border a coast and have a population above a threshold.

In formal terms, if R1 and R2 are families of regions defined by predicates P1 and P2, regionsboth is the subset of regions that belong to both R1 and R2, i.e., regions for which P1 and P2 hold. The phrase is descriptive rather than standardized and appears in documentation and code examples to name a logical conjunction of region sets.

Applications include municipal planning, environmental assessment, epidemiology, and market analysis, where researchers focus on areas meeting multiple criteria. In software, regionsboth can be computed via spatial queries, GIS overlays, or set operations on region identifiers.

Limitations arise from data quality and differing regional delineations, which can complicate the intersection. When regions are defined at different scales or with different borders, reconciliation may be required, using approaches such as spatial union, boundary overlays, or aggregation.

See also: regions, subset, intersection, GIS overlay, spatial query, administrative boundary. References: general GIS textbooks and documentation; examples are widely available in open-source GIS guides.