手法を比較

	Isochrone Analysis	Catchment Area Analysis
分野	Human Geography	Human Geography
系統	Process / pipeline	Process / pipeline
提唱年	1959	1964
提唱者	Edsger W. Dijkstra (shortest-path foundation)	David L. Huff (probabilistic formulation)
種類	Computation of travel-time contours reachable from a location on a network	Delineation of the geographic area served by a facility
原典	Dijkstra, E. W. (1959). A note on two problems in connexion with graphs. Numerische Mathematik, 1(1), 269–271.	Huff, D. L. (1964). Defining and estimating a trading area. Journal of Marketing, 28(3), 34–38.
別名	Travel-Time Analysis, Isochrone Mapping, Service Area Analysis, Travel-Time Contours	Trade Area Analysis, Service Area Delineation, Market Area Analysis, Catchment Delineation
関連	4	4
概要	Isochrone analysis computes the area reachable from a location within a given travel time, drawing contour lines — isochrones — that enclose everywhere you can get to in, say, 15, 30, or 45 minutes. It rests on the single-source shortest-path problem solved by Dijkstra's 1959 algorithm: from an origin, the travel time to every node of a routable network is found, thresholded, and converted into a polygon of reachable space. Isochrones turn an abstract travel-time field into an intuitive map of reach, and underpin service-area planning, accessibility measurement, and location analysis.	Catchment area analysis delineates the geographic area that a facility — a shop, hospital, school, or station — actually serves, turning the abstract question of 'who uses this place?' into a mapped polygon. Methods range from the simplest fixed-radius buffer through nearest-facility (Voronoi) tessellation and network drive-time isochrones to David Huff's 1964 probabilistic model, in which patronage is shared among competing facilities by their relative attractiveness and distance. The choice of method reflects how strictly customers are tied to the nearest centre and how much competition and travel cost shape real behaviour.