LAUSR

Abstract With rapid urbanization, some cities are integrating within urban agglomerations to obtain more opportunities for cooperation. Sustainable development of these agglomerations requires successful management of the material flows, and this requires an in-depth understanding of urban material consumption and its metabolic characteristics. To describe these characteristics, we used flow analysis, factor decomposition, coupling and decoupling status analysis, and power law analysis to examine the metabolic characteristics of Beijing, Tianjin, Langfang, and Tangshan (central cities in the Beijing-Tianjin-Hebei region). We focused on the domestic material consumption (DMC) to analyze inter-city differences in the material metabolism, the driving factors responsible for these differences, and each city's development characteristics. Beijing and Langfang had similar material metabolic fluxes (DMC), as did Tianjin and Tangshan, mainly from the Construction and Manufacturing sectors. The economic size (per capita GDP) and population of the four cities were important drivers of material consumption, but the contributions and trends varied among the cities. Three of the four cities (except Tianjin) have achieved distinct decoupling between consumption growth and per capita GDP growth, and the trends were dominated by relative decoupling (75% of the years). Beijing's and Langfang's DMC become economies of scales as GDP per capita multiplies whereas Tianjin's and Tangshan's DMC increased simultaneously with increasing per capita GDP. Based on these differences in metabolic characteristics and driving factors, we propose suggestions such as carefully regulating the Manufacturing, Construction, Transportation, and Household sectors, as well as implementing policies and technologies to conserve and recycle materials and energy, thereby providing guidance for coordinated and more sustainable development of the Beijing-Tianjin-Hebei region.