No abstract

In the context of “smart cities” and stock-based development, street renewal focuses more on quality and sustainability in China. To improve the efficiency of current smart technology applications, a comprehensive whole-life cycle system needs to be established in street space. After sorting out the application of smart technologies in the street design guidelines (SDGs) for typical cities in China, the compilation and application of smart technologies for sustainability were categorized into five areas: smart transportation, convenient living, life enrichment, the protection of vulnerable people, and environmental monitoring. Based on theoretical support and realistic needs, a smart street management and control platform (SSMCP) was built. The SSMCP is divided into four layers: the basic information layer for the background, the technology platform layer for the core processing, the institutional protection layer for the guarantee mechanism, and the scene application layer for spatial interactions. The results can provide a scientific reference for improving the sustainability of street space and implementing a “smart cities” project at the street level.

Air quality is highly related to the health of a human being. Urban morphology has a significant influence on air quality; however, the specific relationship between urban morphology characteristics and air quality at the neighborhood scale has yet to be investigated, especially the vegetation effect on PM2.5 concentration and diffusion. The relevant morphological parameters based on the affected pathways of urban morphology on air quality were selected, and the sensitivity degree and laws of the selected morphological parameters to PM2.5 were quantified by numerical simulation, bivariate correlation analysis, and regression analysis. The results showed that Building Density (BD), Block Envelope Degree (BED), Average Building Volume (ABV), Average Building Floors (ABF), Standard Deviation of Building Height (SDH) and Greenbelt Coverage Rate (GCR) were Sensitive Morphological Parameters (SMPs). A positive and cosine curve trend of BD and BED with PM2.5 was observed. GCR was significant to dust retention along with vertical canopy height. When ABV = 40,000 m3 and ABF = 20F, the lowest PM2.5 concentration was examined, while increased SDH could promote airflow and enhance the capacity of PM2.5 diffusion. Finally, morphology-optimization strategies were proposed at the neighborhood scale: (1) Decreasing the BED along the street; (2) considering the species of vegetation with the appropriate height and increasing the GCR; (3) increasing the ABF of neighborhoods appropriately while controlling the ABV and distinguishing the internal SDH of neighborhoods. The study could apply the scientific basis for the planning and design of healthy and livable cities.

As one of the most polluted provinces in China, air pollution events occur frequently in Shandong. Based on the hourly (or daily) concentrations of six air pollutants (PM 2.5 , PM 10 , O 3 , NO 2 , SO 2 and CO), the situations of air quality improvement in three kinds of cities (key cities, coastal cities and general cities) are assessed comprehensively during 2014–2020. Contrary to the daily maximum 8-h average ozone (MDA8 O 3 ), the annual average concentrations of other pollutants show the downward trends during 2014–2020. Therein, the improvement rates of annual average concentrations of air pollutants in key cities are highest. By 2020, the day proportions of O 3 as the primary pollutant are up to 38% in three kinds of cities. Besides, due to the impact of COVID-19, the monthly average concentrations of PM 2.5 , PM 10 , NO 2 , SO 2 and CO in February 2020 decrease by 32.1–49.5% year-on-year. There are still about 50% of population exposed to high-risk regions ( R i > 2), which are mainly concentrated in main urban areas and industrial areas. Thus, the adjustment of industrial structure and energy composition in the context of carbon peak and carbon neutrality should be implemented in the future. Supplementary Information The online version contains supplementary material available at 10.1007/s13762-022-04651-5.