دانلود رایگان مقاله ساختار فیزیکی اقتصاد شهری - ارزیابی مقایسه ای

abstract

Urban metabolism provides a characterization of anthropogenic material flows in urban systems and should contribute to identify the economic activities that were involved on their supply and transformation. Typically, its quantification requires data that is not easily available in different geographies. This paper makes use of a methodology based on monetary input–output tables and international trade statistics that might be easily replicable to many metropolitan areas in the world, and which is intended to provide a first rough estimation of urban material flows. The paper discusses the results obtained for four metropolitan areas (Lisbon, Paris, Seoul–Incheon and Shanghai), assessing the material requirements of these economies. The urban areas are compared in terms of the quantity and the type of material input, destination of materials within the economy and their distribution among economic activities. The results showed that while Lisbon is the most diverse urban area in terms of the consumption of material types, it is also the urban area with the least diversified manufacturing sector. The application of this methodology to several urban areas and across multiple years enables the assessment of the technological and economic evolution of those regions.

5. Conclusions

Urban areas are key drivers of economic growth, through technical change, and their environmental impacts have become one of the more important topics due to the growing urbanization trends worldwide. In this context, cities are increasingly perceived as complex systems whose understanding requires a holistic approach, such as that provided by the urban metabolism methods which are intended to characterize the materials that flow in the urban area, how they are transformed by different economic activities and ultimately how they pressure the environment, namely through their extraction and the generation of wastes. This paper presents an innovative method to quantify the metabolism of urban areas, based on input–output data at a national level and scaling down approaches to derive urban scale metabolism. The methodology was applied to four urban areas (Lisbon, Paris, Seoul–Incheon and Shanghai), using the year 2000 as reference.