Abstract of MEMO

As cities grow, available food and water supplies can become limiting, but as the boundaries of the food and water supply regions expand due to increased trade and improvements in transportation, these constraints can be overcome and supplanted with others (Swaney et al., 2011). In the modern global economy, international supply chains are increasingly sourcing products from all over the world. This has increased the diversity of goods and services available to the consumer, but also the potential environmental damage.

The interest in urban metabolism research lies the assumption that, like organisms, cities have distinct metabolisms, i.e. the size and type of metabolic flows of an urban area is influenced by its land-use patterns (or the spatial configuration of cities’ elements), land-use intensity, population density etc. The city size and urban form, as well as the relationship with its environment, and corresponding demand for resources determines (i) the area required to provide water and nutrients to its inhabitants but also, (ii) the area required to retain the city waste, and therefore to ensure the closing of the materials cycle if such sustainable metabolism operates (Cuchí, Marat-Mendes, Mourão, 2010). But, if we are to understand the evolution of urban systems and interactions between society and nature, we must take into account the role of local history and that of the history of techniques – and more generally the history of the environment (Barles, 2007a).

Changes in both environmental sources and sinks affect the ability of the environment to provide life-supporting services such as nutrient cycling, water purification or biological productivity or a viable climate. Current resource state and sink capacity not only influence nowadays ecological functions but will have also impact on its future functioning (Minx et al., 2010). However this link between economy and ecology in the urban context is scarcely investigated. Like natural ecosystems, the urban subsystem is dynamic not stationary, so the status of the demand actors and the associated resource flows are constantly changing. A more precise study of the urban metabolism, focusing on the long term, describes better this behaviour, especially if the quantification of the volumes of matter in play – which constitute the most tangible link between societies and nature, cities and rivers – is accompanied by an analysis of the priorities that guided decision makers for instance in supplying the water and removing the urban wastes that generated these volumes. The analyses must consider the spatial and the territorial contexts, as well as what Barles (2010) designates the agriculture – industry – city triptych.

Additionally, if we want research urban sustainability to inform us on how to build better urban environments, we need to think of the urban form as a tool for integrating issues and problems that were formerly specialized or sub-optimized, counteracting splintering urbanism. To do that, two foundational issues of such an effort would be: (i) a multi-scalar approach that does not handle scale as a pre-given entity (Karrholm, 2011), and (ii) to recover urban form as a tool to assess the environmental pressures of our cities and urban environments, as advanced by Geddes (1915) but also defended by economists as Allier and Schlupmann (1991) and geographers like Naredo & Valero(1999).

The main objective of the current project is to develop a comparative analysis of the metabolic behavior of the Lisbon Metropolitan Area in different historical periods (from pre-industrial period to the present) and therefore assess the behavior of urban form (generically) to the metabolic system in use in its own historical period under review. Additionally it is intended to identify elements of urban form in particular historical moments that were determinant to transform material and water flows in the city.

The city urban structure will be assessed based on methodologies provided by

(i) urban Material Flow Accounting research (Niza et al., 2009, Barles, 2009),

ii) substance flow accounting (Barles, 2007b) and

(iii) assessment of the morphological evolution of the urban form (Marat-Mendes, 2010).

Such assessment of the evolution of urban metabolism aims to evaluate drivers and successful responses to transform the current metabolism promoting a more sustainable urban environment.

The area at stake has been a case-study in the aim of other urban metabolism-related projects developed by the team members like the ResiSt (PTDC/SEN-ENR/103044/2008), the MeSur (PTDC/SEN-ENR/111710/2009) and the IntegerSum (PTDC/SEN-ENR/121747/2010), allowing for synergies concerning data and results. Also, team members researched historical and morphological aspects of the area, including: (i) analysis of the relationship between the cultural identity of Saloia Region and its intrinsic morphological patterns (Marat-Mendes & Cabrita, 2008); (ii) the twentieth century urban transformation of Lisbon (Marat-Mendes, 2010; Marat-Mendes, Sampaio & Rodrigues, 2011); (iii) the relationship between water and the urban morphological patterns of Lisbon landscape (Marat-Mendes, 2011; Chuchí, Marat-Mendes & Mourão, 2010). Additionally, members have developed morphological analysis of Portuguese cities (P0CI/HEC/60004/2004) including the analysis of Portuguese typological elements of urban form (PTDC/GE0/75081/2006).