Influential factors of spatial performance in metro-led urban underground public space:A case study in Shanghai

Spatial performance measures the space usage of each underground segment in metro-led urban underground public space(UUPS).It usually varies in different UUPS segments and at different periods.Many environmental factors and space attractors can influence spatial performance in UUPS including spatial configurations,transportation facilities,space design characteristics,and commercial and work-ing facilities.This study intends to figure out the temporal and spatial distribution patterns of spatial performance in UUPS and then reveal the main influential factors and their impact mechanisms.The UUPS in Jiangwan–Wujiaochang Sub-center was selected as the study case.Cordon counting methods and multiple regression models were employed to collect the pedestrian data and quantitatively analyze the correlations between pedestrian flows and candidate influential factors.The study verified that spatial configurations were the most important factors instead of underground or surface attractors.There existed an interactive effect among pedestrian move-ments,spatial configurations,and commerce distribution in metro-led UUPS.Walkway width and the distribution of metro stations could partly affect spatial performance.The influential mechanisms of metro stations were different on weekdays and at weekends.Underground segments belonging to shopping malls in UUPS had a negative impact on spatial performance only on weekdays.Results of this study can provide insights for more efficient layout planning and design of metro-led UUPS in Chinese metropolitan cities.

Automatic identification and feature recognition of the metro-led underground space in China based on point of interest data

Metro-led underground space(MUS)plays a crucial role in modern underground space utilisation.Recent studies have shown its great potential for high-quality urban development.However,limited evidence about MUS was available on a national scale,resulting in incomplete and unsystematic knowledge of MUS utilisation.The interaction relationship between MUS and the surrounding built environment also remains unclear.To fill the research gap,an automatic method for MUS identification and development features extraction was proposed based on point of interest data.We applied the method to identify the MUS in 28 Chinese cities and estimated the development status of MUS in China for the first time.The nationwide statistics of MUS and correlation analysis of development features were conducted.Results show that complex MUS(CMUS)share is significantly lower than that of simple MUS.Besides,CMUS development in China is primarily dominated by public transport and does not have a solid functional link to its surroundings.The comparative analysis of MUS development in four primary urban agglomerations was also conducted,and their development char-acteristics were discussed.The study aims to expand the planning toolkit and construct the MUS database,which sheds light on the data-driven planning for MUS.

A collaborative approach for urban underground space development toward sustainable development goals:Critical dimensions and future directions

The utilization of urban underground space(UUS)offers an effective solution to urban problems but may also negatively affect urban development.Therefore,UUS development needs better concerted guidelines to coordinate various urban systems and the multiple components of the underground world.Sustainable Development Goals(SDGs),which should be viewed as important yardsticks for UUS development,do not explicitly mention urban underground space,although many of them are affected by both the positive and negative consequences of its development.To fill this gap,this review lays the foundations of relevant UUS concepts and uses exemplary cases to reveal that 11 out of 17 SDGs can be linked with UUS uses.These linkages also manifest that land administration,integrated planning,architectural design,and construction technology are critical dimensions for increasing the contributions of UUS to the realization of SDGs.To achieve multi-disciplinary synergies among these four critical dimensions,a collaborative approach framework based on spatial data infrastructure is required.Thus,this work provides academics and practitioners with a holistic view of sustainable UUS development.