Understanding overlapping functional commuting regions with confidence ellipses and social network methods

Abstract

Functional regions are becoming more and more prominent in spatial planning policies. In this study we assume, that it will be problematic to clearly delimitate these regions in the future. Functional regions will increasingly overlap, because of increasing linkages of functional flows. This study explores different approaches of identifying about these overlapping or fuzzy functional regions, where some municipalities belong to more then one region. Methods are developed and evaluated to quantify and qualify these overlaps. Two methods bring together the perspective of statistical and social network analysis. The first method is an enhancement of the bivariate confidence ellipse. The social network method used to sub-divide large social networks, community detection. The results vary according to the chosen method. Generally, overlaps can be analysed on different hierarchy levels. If the functional overlaps of some neighbouring municipalities are heigh, they will be aggregated to a functional region on a higher hierarchy level. The confidence interval method can be interpreted as the lowest hierarchy level. The methods of social networks show different hierarchies at higher levels.