Effect of street design on UHI and energy consumption based on vegetation and street aspect ratio: Taking Harbin as an example

The vegetation ratio and aspect ratio (H/W) of streets are important factors influencing the urban heat island effect and energy consumption. In order to reduce urban heat island, reduce carbon emissions and achieve sustainable urban development. Field measurement and ENVI-met simulation were performed to obtain optimal conditions for the microclimate and energy consumption. The results showed that the Physiological Equivalent Temperature (PET) was optimized for streets with an aspect ratio of 0.5, with trees occupying 50% of the outdoor area along the northeast–southwest and southeast–northwest orientations. With the same vegetation distribution and street orientation, streets exhibited optimal thermal comfort in cases of an aspect ratio of 0.9 in summer; the same streets exhibited optimized PET in cases of an aspect ratio of 0.3 in winter. When streets with an aspect ratio of 0.5 and northeast–southwest and southeast–northwest orientations were constructed, 30% trees scenario resulted in the lowest energy consumption in surrounding buildings; under a similar vegetation distribution and street orientation, streets yielded the most energy-efficient streetscape when the aspect ratio was 0.9 and 0.7 in both cases. The findings of this study provide a reference for optimizing landscape planning and design in cold residential areas.