Built form and cultural identity : exploring spatial information to understand different spatial cultures

The idea that urban form embodies idiosyncrasies that express cultural identities seems to be a frequent assumption in urban studies. It has to do with the contextual role of custom and institutional settings, from regional idiosyncrasies assimilated to traditional ways of building to the dichotomies of planned and unplanned cities, shaped through topdown agencies or as chance-grown arrangements. However, can local cultures leave traces in urban space? Despite its persistence in the urban imagination, the problem of how built environments might embody specific cultural identities seems yet to be fully addressed in urban morphology. In this sense, historically- and culturally-informed quantitative methods are essential for uncovering forms and patterns resulting from city organisation processes. In this paper, we look closely into that assumption and address the question of whether cities find distinct regional characteristics or take on physically specific forms under certain cultural conditions. This problem implies examining the existence of contextualised ways of shaping cities – and features that might transcend context. We do so approaching the built environment's spatial configurations as a proxy of urban culture, looking into urban form's very constituents. Unlike emphases on street networks, our approach focuses on the elementary components shaping cities' tangible spaces: buildings and how they are aggregated in cellular complexes of built form. Exploring Shannon's information theory, we introduce a measure of information and entropy to analyse the probability distribution of cellular arrangements in built form systems. We apply it to 45 cities from different regions of the world as a similarity measure to compare and cluster cities potentially consistent with specific spatial cultures. Findings suggest a classification scheme that sheds further light on what we call "the cultural hypothesis": the possibility that different cultures and regions find different ways of ordering space

Local and global spatio-temporal entropy indices based on distance- ratios and co-occurrences distributions

When it comes to characterize the distribution of ‘things’ observed spatially and identified by their geometries and attributes, the Shannon entropy has been widely used in different domains such as ecology, regional sciences, epidemiology and image analysis. In particular, recent research has taken into account the spatial patterns derived from topological and metric properties in order to propose extensions to the measure of entropy. Based on two different approaches using either distance-ratios or co-occurrences of observed classes, the research developed in this paper introduces several new indices and explores their extensions to the spatio-temporal domains which are derived whilst investigating further their application as global and local indices. Using a multiplicative space-time integration approach either at a macro or micro-level, the approach leads to a series of spatio-temporal entropy indices including from combining co-occurrence and distances-ratios approaches. The framework developed is complementary to the spatio-temporal clustering problem, introducing a more spatial and spatio-temporal structuring perspective using several indices characterizing the distribution of several class instances in space and time. The whole approach is first illustrated on simulated data evolutions of three classes over seven time stamps. Preliminary results are discussed for a study of conflicting maritime activities in the Bay of Brest where the objective is to explore the spatio-temporal patterns exhibited by a categorical variable with six classes, each representing a conflict between two maritime activities