Enhancing Urban Landscapes through Underground Space Utilization: Public Perceptions

Landscape occupation and green space reduction have decreased livability and hindered the sustainable development of cities. The urban landscape affects the quality of life and physical and mental state of the public, and urban underground space utilization is important for improving the urban landscape. Therefore, underground space utilization must be explored from a public perspective. Referring to typical underground municipal, transportation, and public space projects, an online questionnaire survey of 377 Nanjing residents was performed to construct a structural equation model investigating their perceptions and preferences regarding underground space usage to improve the landscape, focusing on the links between their preferences and opinions. Underground works that provide diverse open spaces were considered to have the most positive impact on the landscape (82.8%). The aesthetic value of the surface landscape (83.5%) and the vitality of historical sites (82.1%) were the most significantly affected, whereas stock underground space had no significant effect on landscape protection. In terms of age, profession, and place of work, the respondents demonstrated heterogeneous preferences. These findings indicate that targeted publicity and public participation are important to strengthen the cooperative utilization of space and realize the potential of the underground space, helping address actual requirements and develop sustainable cities.