Thermal Comfort Effects in Different Open Green Spaces : A Parametric Optimization Study of Urban Spaces Design in China's Cold Region

Thermal comfort and environmental health in open green spaces in cities contribute to sustainable urban development. In this study, research sites were selected in the urban area of Lanzhou, where they have different distances from the Yellow River and have different plant configuration spaces. The thermal perception (thermal sensation, comfort) of the respondents was investigated through meteorological measurements and questionnaires. The results show that: 1) Wind speed decrease significantly with the increase of distance on Yellow River in the three open green spaces. 2) The cold lake effect of the Yellow River dominates the wind environment. 3)As to the closest site to the Yellow River, wind speed had the highest correlation with respondents' thermal sensation. This study also uses the ladybug tool and the plugin of Grasshopper3D for modeling of different sites to simulate urban microclimate and Universal Thermal Comfort Index(UTCI). The results show that 1) there is a strong positive correlation between different spatial measurements and model outputs. 2) UTCI has some discrepancies with the measured values, the fitting degree is high and there is consistency, R 2 = 0.936. Urban planners provide design advice based on the optimization parameters of thermal perception effects and resulting UTCI benchmarks