Spatial accessibility and urban fragmentation in colonial cities. The case of Annaba city

The morphology of the colonial cities in the Maghreb is characterized by certain similarities that are related to their common history. The city includes a Medina, often characterized by some alterations, a colonial city developed along a Haussmannian grid, and new extensions made up of large high-rise housing estates, known in France as "Grands Ensembles". The aggregation of three types of urban patterns contributes to the discontinuity and fragmented character of these cities. Our exploratory study aims at analyzing this overall urban configuration in the specific context of an Algerian city, the city of Annaba (located in the east of Algeria), in terms of spatial accessibility. Our objective will be to evaluate the degree of closure and openness of the different parts of the city. This accessibility will be interpreted along several Space Syntax indicators, namely: spatial integration, intelligibility, and controllability. It is further completed by counts of the pedestrian flows along selected streets, in order to address the relationship between spatial configuration and co-presence in public open spaces.