||The purpose of this thesis was to find out how the physical and spatial properties of a city can influence the urban experience. Two city blocks from Rome´s harbour town, Ostia, (I, xiv/xv) were used as case studies. The urban experience is often studied as a plural and dynamic experience. This thesis applied two types of formal analysis, fractal and visibility graph analysis, to argue and to demonstrate that the urban experience is largely linked to the geometry of the physical and spatial characteristics of the city.
Fractal analysis views cities as structures that resemble a mathematical fractal. Fractals are self-similar, scale invariant objects. Fractal geometry is seen in this thesis as having an effect on the human mind, and therefore on the way a city is experienced. Visibility graph analysis uses the city’s two or three-dimensional plan to analyse its visual integration. Spaces with the highest intervisibility are those spaces which attract most movement, and are therefore the places were social activities occur. Hence these are the places that play the most important role in the urban experience.
A quantitative fractal analysis applied to the city block’s (I, xiv/xv) open spaces revealed that their form has fractal qualities, resulting in a calculated fractal dimension of 1.4551. This value is quite significant since it comes close to the mid-range fractal dimension which has been calculated for the typical savannah landscape. The latter is considered to be a universally preferred landscape where human beings feel at ease. Other fractal properties of Ostia that are less easily quantifiable, these concern the different scales that reside in the city’s urban form. The small scales of the city prevents pedestrians from feeling excluded or alienated from the larger scaled elements of the city. Owing to the organic bottom-up development of certain parts of Ostia, a positive dynamic between the large and the small scales has been achieved.
The visibility graph analysis pinpoints two spaces in the studied area: the square in front of the Temple of Hercules (I, xv, 5) and the open space east of the Baths of Buticosus (I, xiv, 8). The theory of the Urban Information Field was applied to these spaces (Saligaros 2005). It is argued that the surfaces that surround these spaces offer an engaging environment.
The concavity of the spaces allows humans to feel protected, but not trapped. The two spaces have been interpreted as so-called ‘Thirdspace’ (Soja 1996), in which all other urban spaces come together and where urban life is lived.
The analyses have shown that the physical and spatial elements in a city have an impact on the way the city is experienced. By using fractal and visibility graph analyses to examine these elements, this thesis was able to demonstrate that the study of the (past) urban experience can move beyond descriptive and speculative studies, towards a more testable and less subjective urban experience.