An urban material flow analysis framework and measurement method from the perspective of urban metabolism

Adapting a national-scale material flow analysis framework to an urban scale is difficult, so no researcher has yet developed a unified accounting and measurement framework at this scale. However, because cities represent major concentrations of resource consumption and pollution emission, this framework is urgently necessary. Based on the national-scale material flow analysis framework, we focused on the urban-scale material flow and divided a city into 8 compartments to develop a bottom-up accounting framework for urban material flow analysis using these compartments. The measurement and conversion methods for data that cannot be obtained directly from government statistical data were described. Two categories of material flow analysis indexes are explained, namely scale indexes and evaluation indexes. A case study of 13 cities in the Beijing-Tianjin-Hebei region of China demonstrated its application and the insights it provides. In the case cities, Tangshan, Tianjin, Handan showed the largest material consumption and fast rates of growth, and manufacturing is an important source of material consumption. The framework and methods developed in this study provide accounting templates that can be used for material flow analysis of cities at different stages of development both in China and elsewhere, thereby permitting a more unified and comparable accounting and analysis between studies.