Exploring Urban Vitality Characteristics and Interactive Mechanisms at the Community Scale through the Lens of Human Behaviour: A Case Study of Chongqing, China

Abstract. Exploring urban vitality characteristics and interactive mechanisms are helpful for formulating policy, advancing urban planning and promoting sustainable development. However, the characteristics and influencing factors of urban vitality have not been thoroughly explored at finer spatial scales, especially for mountainous cities. In this work, the central urban area of Chongqing is selected as a case study, social, economic, cultural and comprehensive urban vitalities are quantitatively assessed at the community scale. Then, the OLS-XGBoost-SHAP model is innovatively utilized to identify the top influencing factors that interact strongly with urban vitality. Incorporating mountain city footpath and terrain factors, the nonlinear interactions among various factors and vitality are elucidated. The results indicate: (1) the central urban area of Chongqing presents a structure of two main areas, five subareas, and seven clusters. (2) The interaction between the POI diversity index and vitality exhibits a notable threshold effect. When the POI diversity index reaches 0.7, this factor significantly boosts community vitality. (3) The tolerance of transportation in mountainous cities is higher than that in plain cities. When the distance to the nearest subway station and bus station is less than 2000 meters and 650 meters, respectively, these two indicators have a significantly positive impact on urban vitality. (4) Considering mountain city footpath and DEM factors exhibit a strong interactive relationship with POI density, urban planners need to collaboratively optimize the construction layout of these three elements. These findings may provide important insights for people-oriented urban development and planning.