Restorative properties of green sheltered spaces and their morphological characteristics in urban parks

The properties of green space for physical and mental health have been widely demonstrated, especially after the COVID-19 pandemic. However, few studies have systematically focused on spatial indicator thresholds that provide a sense of refuge with restoration benefits. Four morphological indicators as area, coverage, enclosure, and the ratio of width to height(D/H), were quantified for thirty-one scenes in outdoor green sheltered spaces in seven urban parks of Harbin in China. The results show that the sense of refuge and the morphological character of a green space constitute elements that influence restorative properties. Green spaces with different morphological indicators have different restorative properties. The morphological indicator ranges that produce better restorative properties were obtained: 250–500 m2 for area, 0.25–0.35 for coverage, 0.3–0.4 or 0.8–1 for enclosure, and 0.7–1.5 for D/H. This can provide references for the construction of restorative activity spaces in urban parks.