Proximity Analysis
Definition
Proximity analysis measures nearness between features—distances, nearest neighbors, buffers—and interprets implications for access, risk, or interaction. It can be Euclidean (straight-line) or network-based along routes. Analyses include drive-time polygons, nearest facility, spatial joins within thresholds, and kernel densities. Scale and units matter: feet for building codes, minutes for service access. Proximity can imply interaction (e.g., pollution exposure) but is not causation; context like wind or flow direction may dominate. Good practice states assumptions and uses appropriate coordinate systems so results are meaningful and reproducible.
Application
Retailers find closest stores; emergency services dispatch nearest units; environmental analysts assess populations within pollution buffers; planners enforce setback rules; conservationists evaluate species proximity to disturbances.
FAQ
When is Euclidean sufficient?
For open areas or first approximations; but in cities or rugged terrain, network or cost-distance is more realistic.
How to avoid edge effects?
Buffer study areas or include outside features so boundary truncation doesn’t bias nearest-neighbor stats.
Can proximity imply exposure?
Not necessarily; incorporate direction, barriers, and time. For example, downwind matters more than mere distance from a stack.
What CRS should be used?
A suitable projected system in meters/feet for linear measures; avoid degrees for buffer distances.