The rapid pace of urbanization and the increasing concentration of populations in urban areas have generated a substantial demand for architectural structures, resulting in a significant increase in building stock and continuous material flows that interact with the environment. This study emphasizes the importance of high-spatial-resolution mapping of residential building stock for effective urban-construction resource management, planning, and waste management. Focusing on Xi’an as a case study, the research develops a comprehensive framework for mapping urban residential building stock by integrating diverse data dimensions, including temporal, spatial, network, and multi-attribute aspects. The findings indicate that between 1990 and 2020, approximately 4758 residential communities were established in central Xi’an. The analysis of seven key residential construction materials revealed that the building stock escalated from 1.53 million tons to 731.12 million tons, with a steady spatial expansion of material distribution. The study attributes this growth to factors such as population increase, economic advancement, and policy initiatives, which, in turn, have driven the demand for residential building materials and reinforced the interdependence between urban expansion and residential construction development. Remarkably, from 1990 to 2020, the population surged by 2.1-fold, the economy by 66-fold, and the stock of residential building materials by 477-fold, indicating that the growth rate of material stock consistently outpaced that of both population and economic growth. Over the past three decades, the rapid expansion of residential buildings has led to the encroachment of urban ecological spaces by concrete structures. The methodology proposed in this study for quantifying building material offers valuable insights for policymakers and urban and environmental planners to foster responsible resource consumption and supports component-level circularity in the built environment.
Since the beginning of the 21st century, driven by industrialization and its corresponding economic development, China has been experiencing a period of rapid urbanization. The continued expansion of residential space contributes to material stocks of residential buildings, accounting for a large proportion of the total material stocks. Based on a 4D-GIS model, we studied spatiotemporal distribution characteristics and driving factors of residential building material stock in the central urban area of Xi’an from 1992 to 2021. The study innovatively combined this with the spatial development rule, development speed, and expansion direction of cities to analyze the relationship between stock growth and urban development. We found that residential development in central Xi’an is still undergoing a relatively rapid developmental stage. The spatial growth of residential building stock has a distinct agglomeration pattern, showing the characteristics of multi-center agglomeration, and the hot spots of stock growth are concentrated on and expanding to the edges of central cities. The growth of residential building stock has a distinct direction, primarily in the northeast–southwest direction, consistent with the pattern of urban expansion. We also found that social, economic, and transport-related factors are the main drivers of growth of residential building material stock. This study can help policymakers, urban planners, and environmental planners consider the rational development and utilization of land resources and building materials, and it lays a research foundation for the recycling of construction waste in the future.
Primary health care (PHC) facilities play a significant role in constructing a “people-oriented city” to promote sustainable urban development. However, existing studies exhibit gaps in the spatial-performance evaluation of PHC facilities at the block scale and in identifying spatial association types between facilities and the population. Therefore, we examined the elderly population, who rely heavily on PHC facilities, and developed a spatial-performance evaluation model for PHC facilities at the block scale using the Ga2SFCA method and the bivariate spatial autocorrelation method. The results revealed an evident concentric pattern and spatial mismatch between the accessibility of facilities and the elderly population. Facilities in the central area were inadequate due to the excessive density of the elderly population, whereas medical services in suburban areas were unsustainable due to poor accessibility. From a spatial-justice perspective, the spatial-performance evaluation at the block scale can identify spatial correlation types and distribution characteristics between PHC facilities and the elderly population.
According to statistics from the United Nations Environment Program (UNEP), the construction industry accounts for approximately 30% to 40% of global energy consumption and greenhouse gas emissions, making it a major source of carbon emissions. As a critical component of urban construction, residential buildings are characterized by their large scale and significant potential for carbon reduction. Building on this context, this study utilizes diversified geospatial data and applies the life-cycle stage framework for residential buildings alongside the emission factor method to calculate total carbon emissions during the material production, construction, and operation phases. It systematically analyzes the distribution characteristics and spatial evolution trends of life-cycle carbon emissions for urban residential buildings. The findings reveal that 63.06% of the cumulative carbon emissions from residential buildings in Xi’an originate from the operation phase, underscoring the importance of optimizing carbon emissions in this phase as a critical priority for future reductions. Additionally, the spatial distribution of residential building carbon emissions exhibits significant clustering, with an increasingly pronounced expansion pattern. Over time, the direction of expansion has shifted from a northeast–southwest orientation to a northwest–southeast trajectory and continues to extend toward peripheral areas. Economic growth, increased urbanization, and the intensive consumption of specific building materials are identified as significant drivers of residential carbon emissions, while population growth and improvements in material utilization efficiency help mitigate emissions to some extent. This study offers valuable insights to support the green development of China’s construction industry and to advance energy-saving and carbon-reduction strategies.
This study investigates whether duration of working hours affect residents’ preferences for the micro-features of Small Urban Green Spaces (SUGS), and explores differences across genders and visitation purposes. Little is known about this subject, yet it is crucial for creating more equitable green spaces. In phase 1, participants (n = 209; 30.9 ± 6.73 years, 59.3%male) were categorized by average daily working hours (0–8 h, 8–10 h, 10 h+), and rated 41 micro-feature images on their importance for visiting SUGS. Phase 2 included the top ten features ranked from phase 1, with participants (n = 256; 30.8 ± 5.12 years, 35.2% female) completing the Kano model survey to identify and explain the importance of features and different types of needs. Findings reveal a clear trend: extended work hours pivot resident preferences towards green space attributes promoting physical activity. For residents of 0–8 h valued aesthetic elements like sculptures and vegetation, while lighting became paramount for those with 8–10 h, and for those working over 10 h prioritized facilities for active engagement, such as playground equipment and slow runway. These distinctions provide valuable guidance for designing SUGS with diverse feature combinations that cater to the needs of residential areas with varying socio-economic backgrounds and occupational lifestyles, thereby enhancing urban livability.