Yuhong Tian ^a,b,∗, C.Y. Jim^c

a State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China

b College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China

c Department of Geography, University of Hong Kong, Pokfulam Road, Hong Kong, China

Abstract: Sky garden is a hot topic in current research in urban ecology and landscape planning. However, due to the difficulty of data collection and processing, there are surprisingly few published guidelines exploring the spatial distribution of sky gardens and the factors that influence their presence in compact cities. By matching maps of buildings, green cover, district boundaries and roof and podium level layers, the spatial pattern of sky gardens and the factors in Hong Kong were analyzed. Suggestions for future development of sky gardens were also discussed. The results indicate that both roofs and podiums are not adequately utilized by green spaces. High green ratios of roof gardens exist on 5–20-floor buildings or buildings located in areas of low density for most land uses and most districts. Several factors play significant roles in the green ratios of podium gardens in some districts, such as building density in WC, S, E and HKI as a whole and podium areas in WC, SSP and KC. The development of sky gardens has not improved with town development and has not adequately compensated for limited ground-level green spaces. The spacious roof and podium areas that are available provide the potential for the extensive development of sky gardens with high green ratios and biodiversity. Systematic planning on a large scale that incorporates measures for increasing biodiversity and forming green networks may be an effective strategy to solve the problem of the extreme shortage of sky gardens in compact cities.

Keyword: Roof garden; Podium garden; Green ratio; Land use; Building stories; Improvement measure