Intersection (Spatial)

The spatial intersection operation computes the geometric overlap between two or more input feature layers, producing an output that contains only the areas common to all inputs. Each output feature carries the combined attributes from the overlapping input features, enabling analysis of where multiple spatial conditions or characteristics co-occur.

Intersection clips each input feature by the boundaries of the other input layer, retaining only the portions that fall within both. For polygon-on-polygon intersection, the result is a set of polygons representing the shared areas. For point-on-polygon intersection, only points falling within the polygon layer are retained. For line-on-polygon intersection, lines are clipped to the polygon boundaries. In all cases, the output features inherit attributes from both input layers.

Environmental analysts intersect habitat range maps with protected area boundaries to determine how much of a species' range falls within conservation areas. Urban planners intersect proposed development zones with environmental sensitivity layers to identify areas requiring environmental review. Emergency managers intersect population layers with hazard zones to estimate the number of people at risk. Tax assessors intersect parcel boundaries with school district boundaries to assign tax jurisdictions. Transportation planners intersect traffic analysis zones with census tracts to integrate demographic and travel data.

Intersection produces output only where inputs overlap, so areas unique to a single input are discarded. If comprehensive coverage is needed, union is more appropriate. Like other geometric operationsGeometric OperationsGeometric operations are spatial transformations applied to vector geometries, including union, intersection, differe..., intersection can produce small sliver polygons along shared boundaries due to coordinate precision issues, which may require cleanup.