Natural periodicity demonstrates a natural spatial area-isation at all scales, reflecting the ways in which we talk about urban areas and regions at different scales.
Natural periodicity
Sources
Hillier, B., Turner, A., Yang, T., Park, H-T. (2007, 2010) Metric and topo-geometric properties of urban street networks: some convergencies, divergencies and new results. The Journal of Space Syntax, V(1) 2, 258-279. pp. 260