Figure 5. •
This approach is coherent with a recent innovation in urban analysis used by urban climatologists: the division of the urban surface into strongly differentiated local climate zones, each defined by the surface cover (built fraction, soil moisture and albedo) and its structure (sky view factor and roughness), and human activities (anthropogenic heat flux). Iraq _______
Figure 3. The phrase ‘urban metabolism’ was in use almost 50 years ago16 in reference to a hypothetical city of 1 million people, and elaborated in more recent studies of eight metropolitan cities across five continents,17 although these studies are focused on the quantification and annual totals of flows rather than the network topology of their architecture and its relation to the morphology of the city. The study and design of infrastructures is conventionally focused on the separate physical artefacts of the networks, and in recent times there has been strong focus on the architectural renewal and implementation of stations, bridges and terminals, but much less on the topology and physical architecture of the network systems themselves or on the interdependencies between differing infrastructural systems and even less on their integration. However, in all living forms, metabolism and morphology are intricately linked and operate through surfaces and networks. Gradient boundaries
The legal and regulatory boundary is often defined by the original core, so that cities are regarded as something quite separate from their surrounding territory. The exponential acceleration of population growth and the projected proliferation of new cities requires the development of new ‘flow’ architectures, of ‘metabolic’ and intelligent inhabited urban infrastructural systems that harvest and distribute energy, water and materials, that intimately connects people and open urban green spaces, and that unites rather than divides urban and ecological systems. All cities have. There are no known large-scale studies that couple the analysis of urban morphologies, the flows and capacities of their metabolic system, to the design of the physical geometries and engineering of material artefacts that comprise integrated urban metabolic systems within a regime of rapid climatic and ecological change, rising population and energetic constraints. Mammalian metabolisms, for example, evolved their long intestinal tube with very large numbers of convolutions to increase the surface area, and use muscles to accelerate the passage of food. Morphology and metabolism are related in plants through the spatial organisation of large surface areas to capture light and for the exchange of gases, the structural system for the deployment of those surfaces, and the internal transportation systems for moving fluids. And within the cells, the evolution of increased mitochondrial surfaces through multiple foldings amplified the energy-processing capacity of cellular tissues. The evolution of greater surface areas for respiration, the intricate surface foldings of lungs in mammals and in birds, produces large surface areas for the exchange of gases packed into internal cavities. Figure 4. 1 Nine parameters for modelling the surface of the city
below: These diagrams show the relation of the urban surface to climate and environment, and the mathematical description used for analysis of the differentiated material and spatial conditions; and when combined with urban climatology, for environmental performance and energy use. It is now widely accepted that urban morphology and density, and the evolution of transportation technology influence both
Figure 7. and cavities that together comprise the morphology. Enhanced circulatory systems were evolved by the development of more complex hearts and increased fluid pressures, as was the oxygen-carrying capacity of the blood being circulated. There are contemporary related analytical studies into the metabolism of discrete patches of a city.18 This offers the potential to compare the annualised total flows of energy and material in and out of different urban patches, but without morphological analysis only generalised inferences may be made. the energy and material flows through cities. The relation of this porous material surface to its climate and environment, and thus to its energy consumption, is amenable to mathematical description, and may thus be used for analysis of the differentiated material and spatial conditions across the urban surface that influence and moderate the local urban microclimate19 and consequently to its environmental performance and energy consumption. Figure 6.