Estimating public space metrics from nineteenth-century urban cartography: Barcelona’s Cerdà Plan of urban expansion

Abstract

Urban cartography enables us to trace the historical and spatial evolution of human settlements, but it also furnishes us with the opportunity to obtain and analyse urban data from the perspective of the present day. Urban plans drafted for the reform and expansion of a city can provide us with valuable urban information about the planned use of new public space. In Western Europe, the historical cartography of Barcelona (Spain) maps the city’s mid-nineteenth century urban expansion project designed to fulfil egalitarian, social and hygienist goals. Here, using geographic information system tools, we digitize Barcelona’s cartography so as to create an urban dataset based on the city’s urban plans – the Cerdà Plans (1859 and 1863) – and to estimate its public space typology. Social centres, hospitals, green spaces, residential areas and communication infrastructures are identified and metrised, and urban public open spaces are analysed using various urban indicators. The urban data thus obtained represent a notable advance on attempts to quantify Cerdà’s original project. The importance attached to public space (>75%) and to both communication infrastructure and urban public open spaces is indicative of the desire to create a new city and to break with the values of old Barcelona. In short, the data obtained serve to undertake a detailed comparison with the present-day reality of Barcelona.

Understanding Urban Complexity via the Spatial Diversity of Activities: An Application to Barcelona (Spain)

“…The urban expansion that occurred in the Eixample, centred on closed housing blocks, separated by streets 15 to 20 m wide, with population densities greater than 250 inhabitants/ha and with levels of income close to the city average, appears to provide the highest density and diversity of activities, especially when compared to the capacity afforded by other regular and irregular morphologies. Some of the increase in the diversity of the Eixample district today may be attributable to modifications to Cerdà's original project, which has undergone changes, as city ordinances to close off the blocks were approved [76,84]. Originally, the plan allowed a densification of activities in the block's ground floors which, at the time, made the Eixample the district with the highest number of industrial activities.…”