areaswhere

Areaswhere is a term used in geospatial analysis to describe the spatial extent where multiple conditions or criteria hold simultaneously. The word combines areas and where to denote the subset of a geographic space that satisfies specified predicates. In formal terms, areaswhere refers to the intersection of geographic regions that meet each criterion, i.e., the set of locations x such that P1(x) and P2(x) and ... Pn(x) are all true.

Computation of areaswhere is done by overlaying spatial layers and applying spatial operations. In raster data, thresholding and boolean masks create binary layers that are then combined by a logical AND. In vector data, geometric intersections of polygons or buffered zones yield the resulting areas. Geographic information system software supports these analyses, using spatial SQL (for example, PostGIS), or tools in QGIS, ArcGIS, or GRASS GIS, often via Python libraries such as GeoPandas or Shapely.

Applications of areaswhere span site selection, urban planning, environmental management, disaster resilience, public health, and telecommunications, where it helps identify zones that satisfy combined criteria. For example, one might seek areas within 5 kilometers of a water body, with population density above a threshold, and slope below a given limit to locate suitable development sites or service areas.

Limitations include dependence on data accuracy, scale, and the chosen criteria. Results can be sensitive to thresholds and data updates, which may influence policy or investment decisions. See also suitability analysis, overlap analysis, multi-criteria decision analysis, and spatial overlay.