Mapping nationwide material stock turnover: High-resolution spatial analysis of building material stock and flow...

Understanding the dynamics of building material stocks and flows, including the turnover processes of building stock, is important for promoting sustainable resource use in cities. This study provides high-resolution, integrated mapping of building material stocks and flows across various cities and regions in Japan, offering a detailed view of the country's spatial material metabolism. This research combines bottom-up estimates of material stocks and flows with spatial analysis using material metabolism indicators, examining how patterns of material stock turnover vary across Japan. Spatial variations in material stock turnover highlight regional factors that influence stock-flow dynamics and offer insights into local resource use and policy development tailored to specific regional contexts. In this study, the national stock turnover rate in 2020 is estimated to be 1.16%/year for inflow and 0.64%/year for outflow, with more active metabolism observed in the central areas of large metropolitan regions and lower levels in low-density rural areas. Additionally, distinct patterns of material metabolism were observed across districts, associated with redevelopment and urban sprawl. This study illustrates how spatially detailed approaches can support the analysis of stock-flow dynamics across the country and contribute to the development of sustainable resource use strategies tailored to local conditions.

The online version of this article (doi:10.1111/jiec.70100) contains supplementary material, which is available to authorized users.