## 5 Analysis of Influencing Factors of Urban Vitality
### Exploration of the Spatial Relationship Between Urban Vitality and Influencing Factors
Commercial facilities accessibility showed the highest association with urban vitality, with the strongest correlation observed along Zhongshan Road and neighboring subdistricts in Shinan District, and reaching its lowest in Wangtai Town Subdistrict of Huangdao District and Xifu Town Subdistrict of Chengyang District, with spatial patterns indicating lower values in the western and eastern areas, higher values concentrated in the central zone and reduced levels in the peripheral surroundings. The cultural and leisure facilities accessibility exerted a stronger influence on urban vibrancy in eastern cities compared to western ones, with the eastern region showing a gradual increase in impact spreading from the east to the west, while the western region experienced a more subdued effect. Although the correlation between building height and urban vitality was weaker than that of cultural and leisure facilities accessibility, it was strongest along the eastern coastline, gradually decreasing laterally. The influence of resident population density on urban vitality is concentrated around the subdistricts of Shinan and Shibei Districts, exhibiting a radially declining pattern outward, while in Chengyang District, this effect gradually diminishes from west to east, with the weakest negative impact observed in the northwestern subdistricts. At the micro-medium scale, urban vitality is significantly influenced by nine environmental factors: resident population density, building height, greening rate, functional mixing degree, metro accessibility, road network density, accessibility to commercial, public and cultural and leisure facilities. Within the dimensions of density and diversity, resident population density exhibits a slight negative association with urban vitality, with this correlation being strongest in the eastern neighborhoods and gradually diminishing toward the west, which suggests that, in densely populated areas, the resident population density has approached saturation. The functional mixing degree exhibits the strongest correlation with urban vitality along the eastern coastal neighborhoods, gradually diminishing toward the surrounding areas. Enhancing functional diversity can effectively improve regional vitality, with this effect being particularly pronounced in urban central areas. Within the design dimension, building height is generally positively correlated with urban vitality, with the strongest associations observed in the blocks of Shinan Districtand the western and northeastern areas of Chengyang District. This correlation gradually weakens outward from these three focal areas, indicating that urban renewal in central districts can benefit from appropriately increasing building heights to accommodate a greater diversity of land uses. The relationship between greening rate and urban vitality is complex. In the northern neighborhoods, a negative correlation is observed, with the strongest adverse impact among all built environment indicators, indicating poorer conditions for green space development in urban fringe areas, while positive correlations are found in the western, central and southern neighborhoods, where the strength of this association gradually decreases from Shinan and Shibei Districts toward the surrounding areas. Within the dimension of distance to transit, urban vitality exhibits the strongest correlation with metro accessibility, showing an overall negative relationship whereby proximity of a neighborhood center to a metro station enhances local vitality, and since metro stations are primarily concentrated in the central areas of each district, this effect is particularly pronounced in the peripheral zones of Guangdong and Chengyang Districts. An increase in road network density enhances regional accessibility and can, to some extent, stimulate the improvement in urban vitality; this effect is particularly pronounced in the northwestern Chengyang District and the western Huangdao District, while it is comparatively weaker in areas such as the scenic zones of southern Laoshan District.