School of Information Management, Beijing Information Science & Technology University, Beijing 100192, China.
Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601, Japan; School of Environment, Tsinghua University, Beijing 100084, China.
Sci Total Environ. 2024 Nov 15;951:175634. doi: 10.1016/j.scitotenv.2024.175634. Epub 2024 Aug 19.
Japan's unique demographic trajectory, marked by population decline and aging, coupled with continued urbanization, presents distinct challenges for aligning built environment capacity with resource efficiency. This study aims to investigate the historical evolution and project future scenarios of building material stock (MS) and their spatial distribution across Japan's three major metropolitan areas. Through a comprehensive material flow and stock analysis, the historical accumulation of building materials from 2009 to 2020 was quantified, revealing a dominance of concrete and an increasing overall stock. The contributions of various driving factors to changes in construction areas were explored, identifying population dynamics as the predominant influence. Leveraging shared socioeconomic pathway scenarios (SSPs), this research forecasted building floor area and MS until 2050 under five distinct SSPs. The results indicated an overall reduction across all scenarios, yet with a continued concentration in high-density urban cores. The substantial gap between the highest and lowest projected MS scenarios highlighted opportunities for material conservation and emission reductions through sustainable practices. Sustainable urban development in densely populated regions necessitates a balance between infrastructure provision and environmental conservation, while in sparsely populated areas, the focus shifts to the efficient management and utilization of vacant properties and materials to cope with the impacts of significant population declines. By offering insights into the building floor area and MS implications of Japan's demographic changes, this study underscores the necessity of sustainable urban planning and resource management strategies to navigate the challenges posed by demographic shifts, ultimately contributing to sustainable development and environmental conservation goals.
日本独特的人口趋势，以人口减少和老龄化为特征，加上持续的城市化，给调整建筑环境容量与资源效率的一致性带来了明显的挑战。本研究旨在调查日本三大都市圈建筑材料存量（MS）的历史演变和未来情景，并分析其空间分布。通过全面的物质流动和存量分析，量化了 2009 年至 2020 年建筑材料的历史积累，揭示了混凝土的主导地位和总体存量的增加。探讨了各种驱动因素对建筑区域变化的贡献，发现人口动态是主要影响因素。利用共同社会经济途径情景（SSP），本研究预测了在五个不同 SSP 下，到 2050 年的建筑面积和 MS。结果表明，所有情景下的建筑面积总体减少，但在高密度城市核心区仍持续集中。最高和最低预计 MS 情景之间的巨大差距表明，通过可持续实践，有机会进行材料节约和减排。在人口密集地区，可持续城市发展需要在基础设施供应和环境保护之间取得平衡，而在人口稀少地区，重点则转移到有效管理和利用空置财产和材料，以应对人口大幅减少的影响。本研究通过探讨日本人口变化对建筑面积和 MS 的影响，强调了可持续城市规划和资源管理策略的必要性，以应对人口变化带来的挑战，最终有助于可持续发展和环境保护目标。
