Current shading strategies used to protect outdoor playgrounds from harmful solar radiation include the placement of artificial cloth weaves or permanent roofing over a playground site, planting trees in proximity to playground equipment, and using vegetation or surface texture variations to cool playground surfaces. How and where an artificial shade structure is placed or a tree is planted to maximize the shade protection over specific playground areas, requires careful assessment of local seasonal sun exposure patterns. The Playground Shade Index (PSI) is introduced here as a design metric to enable shade and solar ultraviolet exposure patterns to be derived in an outdoor space using conventional aerial views of suburban park maps. The implementation of the PSI is demonstrated by incorporating a machine learning design tool to classify the position of trees from an aerial image, thus enabling the mapping of seasonal shade and ultraviolet exposure patterns within an existing 7180 m 2 parkland. This is achieved by modeling the relative position of the sun with respect to nearby buildings, shade structures, and the identified evergreen and deciduous tree species surrounding an outdoor playground.

This research compared personal sunlight exposure times monitored electronically within suburban Australian environments against self-report paper journals for determining the timing and total duration of individual exposure to daily solar radiation. A total of 90 Electronic Sun Journal (ESJ) daily readings and self-report timing and duration estimates of exposure for weekend and weekdays were compared. A Wilcoxon ranked sign test showed a significant difference (V = 157, P < 0.001) between the duration of exposure recorded electronically and the duration of exposure that was self-reported in a diary. There was also found to be a statistically significant difference between total exposure time measured using both methods for weekends (V = 10, P < 0.001) and weekdays (V = 87, P < 0.001). General trends in outdoor exposure timing confirmed that the most frequent daily exposures received over the weekend occurred between 1 and 2 h earlier than the most frequent exposures received on weekdays. This preliminary research found that exposure durations as recorded by the ESJ were longer on the weekends compared to weekdays (W = 402, P < 0.001) and confirmed that the ESJ is a viable alternative to self-reporting diaries.