The effect of visibility on green space recovery, perception and preference

Urban green space serves as an important restorative environment for alleviating the physiological and psychological stress of residents, results which are primarily achieved through visual perception. However, air pollution results in decreased visibility, affects visual perception, and thus redues the positive effects of the experience of using the green space environment.There is a limited number of related studies. Therefore, based on the Stress Reduction Theory (SRT), this study constructed 12 groups of green space environments with different degrees of visibility and compared the physiological (SCL, alpha-EEG / beta-EEG) and psychological (TMD) restorative effects of the participants in different environments by using photo elicitation. Combined with the perception and preference of green space, the impact of air pollution on the restoration received from the environment was explored. The results show that: (1) Visibility and green space type can affect the level of green space recovery. When the visibility is poor, the semi-open and semi-closed green spaces resulted in the best recovery; (2) When the visibility is reduced, the participants' perception of the eight types of Perceived Sensory Dimensions (PSDs) is generally reduced, and the type of green space is related to the perception of air quality; (3) As visibility decreased, participants' preference for green spaces significantly decreased; and (4) Visibility will affect green space perception and preference, thus affecting its recovery. This study provides a basis and reference for the design and construction of a higher quality restorative green space environment to effectively account for air pollution problems.