Quantifying the Coherence and Divergence of Planned, Visual and Perceived Streets Greening to Inform Ecological Urban Planning

Abstract

This research attempts to combine the fields of urban planning, urban design and cognitive psychology, and propose three corresponding evaluation indicators for urban ecology, and further explore the coherence and divergence between them. This research defines land vegetation coverage, visibility of street green vegetation, and people's green perception as planned green, visual green and perceived green. Specifically, the three measures (i.e., planned, visual and perceived) refer to objectively extracting park lands and canopy areas from land use data, objectively extracting green pixels from street views, and subjectively collected through visual surveys. This study hypothesizes that there could exist large variation between the three measures, which would provide distinct implications for city planners. To test our hypothesis, this study selects Brisbane as the research area, effectively using computer deep learning, data visualization and mathematical statistics methods to achieve an accurate description of the three sets of data, and proposes a comprehensive evaluation of the urban ecological theory system. The results show the credibility and scope of application of the three types of greening, and quantitatively proposed and tested the relevant theories of urban design.