关键词: 地下公共活动空间, 城市公共中心体系, 多尺度协调作用, 空间格局

Abstract: In this study, measurements of the coordinating effect of underground public spaces on the urban public center system are presented to support and guide the integrated and systematic planning of urban public spaces both aboveground and underground. The spatial patterns of urban public spaces and human public activities are identified based on points of interest and real-time population activity intensity data, respectively. The global coordinating effect of underground public spaces is measured by comparing the similarities between the patterns of urban public spaces (including and excluding underground public spaces) and human public activities. The local coordinating effect is measured by comparing the deviation of clustering centers of the three spatial distributions. The methodology is applied to an empirical study of the Jing′an district, Shanghai, China. Conclusions are drawn as follows: (1) The layout of underground public spaces in the Jing′an district primarily exerts a coordinating effect at the meso-and microscale, with the intensity of the effect decreasing rapidly with the expansion of the study radius. (2) The local measurements reveal and distinguish the centripetal and the centrifugal effects of underground public spaces: the former improves the efficiency of public space supply in lessdeveloped urban areas, whereas the latter transforms an agglomeration effect into a spillover effect. (3) There is a staggered layout of underground public spaces in the northern part of the Jing′an district and along the Suhe creek, where the centrifugal effect exists. (4) Global measurements with 200 m and 500 m radii, combined with local measurements and qualitative analysis, can effectively reveal the coordinating effect of underground public spaces and are suitable for inclusion in the monitoring index system for the construction of urban public center systems.

Key words: underground public spaces, urban public center system, multiscale coordinating effect, spatial pattern