Lacunarity and the size of road network as contributors to spatial identity: Informal patterns vs. vernacular urban settlements

Abstract

This paper aims to contribute to the debate on the "reading" of urban morphologies through quantitative means. The research objective is the establishment of a numeric method for comparing spatial characteristics of different families of urban morphologies, by considering the degree of fragmentation as a key contributor to their spatial identity. The hypothesis elaborated in this paper is that the fragmentation degree of urban textures can be adequately described through a set of fractal parameters. In addition to the fractal dimension, lacunarity is used in order to complete the analytic model. The intricate relations between morphologic characteristics of the built form and urban mobility are analyzed by referring to the network size and network density of the roads system. The experiment consists of two phases: phase one produces binary images of urban samples belonging to different families of urban morphologies. The focus of the experiment is placed on several informal and vernacular zones in Albania. Over the second phase, the values of fractal indexes, the network size and network density on the binary images of urban samples are measured. The outcome of the experiment purports to establish that the spatial characteristics of different urban morphologies can be adequately expressed in numeric terms. Informal urban patterns are characterized by higher values of lacunarity and lower values of roads network densities compared to vernacular ones, even though they appear to have similar values of fractal dimensions. The outcome of the experiment opens up new perspectives in relation to urban design practices and planning processes.