How to plan urban green space in cold regions of China to achieve the best cooling efficiency

Abstract With the acceleration of urbanization, the urban heat island (UHI) effect has intensified. Urban green space can retard the UHI effectively. However, most existing work has only focused on hot regions, while little attention has been paid to cold regions. Furthermore, existing research does not classify urban green spaces according to the presence or absence of water, which will lead to inaccurate results. This paper takes four cities in cold regions of China as examples and studies the cooling effects of two different types of urban green space. The results indicate that for green spaces without water, the cooling intensity is related to the background temperature and area of the green spaces, while for green spaces containing water bodies, the area of the internal water body is the key influencing factor. Specifically, there is a threshold value of efficiency (TVoE) for the area of green spaces without water, while there is no TVoE for green spaces containing water bodies. Additionally, there is a TVoE for the water/land ratio of the green spaces containing water bodies in the four cities. The methods and results of this study can provide reference for future research and for urban planners designing urban green spaces.