The design of urban spaces could greatly influence the ability of green spaces to improve the thermal environment. Wuhan in the hot-summer and cold-winter zone situated in the central and lower reaches of the Yangtze River in China, has numerous green parks and other natural resources. There is a demand to integrate environmental resources to improve the thermal environment in this city. This research was conducted using multidisciplinary methods including remote sensing inversion, extraction of spatial information, measurement of a multisystem thermal environment index, questionnaires, computational simulations and statistical analysis. By using these methods, the relationship was established between different types of green spaces, urban layouts in different scales and thermal environmental parameters. A multidimensional method for the design of green and urban spaces was developed with the aim to improve the urban thermal environment. The results showed that the relationship among thermal comfort parameters, such as temperature, wind speed and humidity would be influenced by urban layout surfaces and had close relationship with the characteristics of residents' behaviours. The regression models using the physiological equivalent temperature can express the condition of thermal comfort in green spaces quantitatively.

Outdoor thermal comfort in urban residential areas is closely related to the daily lives of their residents. Nine residential communities in Wuhan, a typical city in central China, were selected as the research object. A questionnaire survey, meteorological parameter measurements, and data analyses were used to investigate the influences of factors such as the characteristics of the spatial environments and the types of outdoor activities undertaken by the residents on the levels of comfort. This investigation was expected to provide a reference for improving these levels. The results show that the level of satisfaction of those in areas with building heights of more than 15 stories reached 51%. Wind speeds were higher in medium-density areas while comfort was the highest in residential areas with densities between 22% and 30%. High-quality areas, which benefitted mainly from higher sensations of wind speed, had the highest levels of comfort but the strongest sensations of heat. A positive correlation exists between green areas and comfort. Where the green coverage rate exceeded 70.0%, temperature satisfaction increased to 33.3–66.7%. Areas with impervious paving are negatively correlated to temperature sensations. Areas of 400–625 m² had levels of temperature satisfaction lower than 21.5%.

Under the influence of the urban heat island effect, the thermal environments of urban built-up areas are poor, leading to the loss of urban vitality and the extreme deterioration of thermal comfort. In this paper, the outdoor thermal environment in Wuhan’s main urban area is studied via the use of field measurements. From June to August in the years 2015 to 2017, 20 measurement points were selected for monitoring from 08:00 to 19:00 h, which were located in spaces such as residential areas, parklands, commercial streets, and college/university campuses. The measurements for the same types of land and different types of land use are analyzed. A comprehensive thermal environment index is used to quantitatively evaluate the overall situations of thermal environments. The results showed that the cooling effect of vegetation shading was stronger than the effect of water evaporation and the maximum temperature difference between the two cooling methods reached 6.1 °C. The cooling effect of the canopy shading of tall trees was stronger than the effect of grassland transpiration and the maximum temperature difference was 2.8 °C. The streets with higher aspect ratios might improve the ventilation, but the wind speeds remained low, which did not provide a strong cooling effect. This study helps urban planners understand the thermal environment of Wuhan or similar cities with hot summer and diversified urban areas, and puts forward suggestions to reduce the heat island effect from the aspect of building layout, green coverage, shading mode, and street aspect ratio, so as to establish sustainable cities that are climate adaptable and environmentally friendly.