Toward a comprehensive understanding of eye-level urban greenness: a systematic review

Figures & data

Figure 1. The conceptual structure of this review.

Figure 2. PRISMA flow diagram for selecting eligible studies, and $n$ means the number of papers The method is adapted from Moher et al. (2009).

Table 1. Thematic clusters and subtopics categories.

Groups	Topics
Physical behavior	Activities
	Exposure
Public health	Mental Health
	General Health
Urban planning	Urban Design
	Urban Environment
Human perception	Citizens’ Satisfaction
	Emotion
Inequity	Socioeconomics
	Economy

Figure 3. Statistics of the eligible papers. (a) The number of papers published per year; (b) data sources used to measure eye-level urban greenness and their associated percentages; (c) study region involved and the number of studies in these countries; (d) domains defined based on the outcome of this study and their associated percentages.

Table 2. A brief summary of the identified three primary measurements of eye-level urban greenness.

Measurement	Data source	Method	Applicability	Pros	Cons
Street view images	360-degree images	Pixel extraction, computer vision	Vehicle-accessible areas	Accurately reflects human-perceived greenness along roadways	Restricted coverage
Field photographs	Manually captured photos	Pixel extraction, computer vision	Walkable areas	Customizable, targeted data collection	Time- and labor-consuming
Simulation	Multi-source Geospatial data	Viewshed analysis	Comprehensive coverage	Replicates human sight in complex 3D environments	Computationally demanding and data-intensive.

Moher, D., A. Liberati, J. Tetzlaff, D. G. Altman, D. Altman, G. Antes, D. Atkins, et al. 2009. “Preferred Reporting Items for Systematic Reviews and Meta-analyses: The PRISMA Statement.” PLoS Medicine 6:e1000097. https://doi.org/10.1371/journal.pmed.1000097.

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