Mapping overlapping community areas: DFG-SNF-Projekt: Räumliche Erreichbarkeiten und die Dynamik der Pendlerverflechtungen in Deutschland und der Schweiz 1970-2005

Abstract

This article focuses on mapping and delineation of commuting areas. Commuting distances and the complexity of commuter flows have increased steadily over the years. A reasonable gener- alisation for the representation of the commuting areas for different purpose is needed. Different cartographic representations, linear and 2-dimensional, overlapping and non-overlapping, are discussed. A commuting area describes a 2-dimensional “sphere of influence” of an urban core. Traditional procedures for delimiting these areas assign each municipality to a single catchment area. One possibility for defining functional areas is the intramax algorithm (FLOWMAP 7.2). This algorithm ignores the overlaps and the differentiation between incoming and outgoing flows. A classical method of transport planners is mapping of interaction where origin and des- tination is connected with a straight line. Alternatively, methods are generating measurable overlapping commuting areas of inflows. Four different stages of, from a morphological to a circular shaped area, are discussed. Additionally, various overlaps between the catchment areas of centres of equal and unequal rank can be determined.