Influencing Mechanism of Outdoor Visual,Thermal,and Acoustic Environments on Spatiotemporal Vitality in Summer:An Empirical Study based on Wuhan's Pocket Parks

LI Chuancheng; ZHANG Dongfang; YE Renyuan; ZHOU Xilin

doi:10.3969/j.issn.1000-0232.2025.09.010

Abstract：As critical micro-spaces in high-density urban areas,pocket parks serve as vital venues for facilitating resident activities,enhancing neighborhood interactions,and fostering community cohesion.Although existing studies have examined the impacts of visual,thermal,and acoustic environments on human activities within urban public spaces,it has predominantly focused on large-scale settings and relied on subjective evaluation.Targeted investigations into micro-spaces,typified by pocket parks,remain scarce.There is also the superposed effect of extreme heat,high humidity,and traffic noise in regions where the summers are hot and the winters are cold.The influence of these environments on the spatiotemporal vitality of people in pocket parks,as well as the differential response laws of pocket parks with varying functions in this process,has not been systematically and deeply analyzed. This study aimed to investigate the influence of visual,thermal,and acoustic environments on the spatiotemporal vitality of user activities,clarify the synergistic mechanisms underlying these environmental effects,and provide references for precise environmental design of pocket parks in regions where the summers are hot and the winters are cold.Four typical types of pocket parks in Wuhan(namely,residential,public visitor,transportation,and business)were chosen as the research objects.The parks were divided into 81 grids(15 m × 15 m)using fixed-point measurements and manual grid annotations.Data were collected on three successive sunny days in August 2024.Indicators of the visual environment were quantified by combining images from a panoramic camera and the deep learning-based semantic segmentation technique.Vegetation parameters were acquired by unmanned aerial vehicles(UAVs).The parameters of the thermal environment were monitored by thermohygrometers and black globe thermometers,and physiological equivalent temperature(PET)was calculated.For the acoustic environment,sound levels were measured and calculated using the integrating sound level meter.The spatiotemporal distribution of users with different intensities during activities was recorded via manual grid annotation.Pearson correlation analysis quantified the connections between environmental factors and user activities.Gender and age were recorded. The research results reveal that the impact of visual,thermal,and acoustic environments in different types of pocket parks on the vitality of users with different activity intensities varies significantly.The environmental effects complicate matching relations with park functions and activity attributes.(1)The visual environment guides behaviors via accessibility,the ratio of seating amenities,and spatial permeability.The proportion of seating amenities exhibits a significant positive correlation with the number of users across all activity types.Vegetation visual openness only shows a positive correlation with the number of users engaged in static and low-intensity activities.The effect of hard paving is prominent in residential and public visitor parks.Activities in transportation parks reveal weak sensitivity to visual environmental factors,since they prioritize transportation activities.(2)The effects of the thermal environment have an inflection point.After reaching a specific numerical value,the behaviors of users change.Temperature and black globe temperature are significantly correlated with the number of users in residential,public visiting,and business parks.Major users of transportation parks show the lowest sensitivity to the thermal environment.(3)The acoustic environment exhibits context-dependent adaptability,and the magnitude of the effect is regulated by activity types and site functions combined.Static activities in business parks demand a low-noise background,while moderate-intensity activities in residential parks are more tolerant of background noise. Based on the analysis,a three-level spatial optimization strategy is proposed:at the universal level,excessive noise is mitigated by reducing objective noise indicators and enhancing subjective acoustic perception while realizing the synergy of denoising and cooling.Different interventions should be adopted in different parks,and the spatial configuration should accord with user characteristics.By analyzing the correlation mechanisms between visual,thermal,and acoustic environments in pocket parks in regions where the summers are hot and the winters are cold and the spatiotemporal vitality of users,this study provides scientific support for the climate-adaptive design of urban micro-spaces and offers technological strategies for precise improvement of the outdoor environment and the construction of healthy human settlements.