Influences of wind direction on the cooling effects of mountain vegetation in urban area

Abstract

The mountain or hill with lots of natural vegetation in a city has obvious cooling effects, so it can play a significant role in the regulation of urban microclimate and mitigation of urban heat island (UHI). In this paper, the influences of wind direction on the cooling effects of the Zijin Mountain in Nanjing were evaluated. Firstly, the land surface temperature (LST) was obtained based on 15 Landsat-8 images from 2013 to 2020, and the wind directions in 4 h before the satellite crossing time were calculated. Then, two remote sensing images with opposite wind directions were compared and analyzed to explore the influences of wind direction on the cooling effects of the Zijin Mountain. The results showed that both the cooling buffer zone method and the cooling area method proposed in this paper had proved that the wind direction had great influences on the cooling effects of the mountain vegetation in urban area. In addition, it was also found that the larger the wind speed differences of group images, the greater the influences of the wind direction on the cooling effects. This study will be helpful and meaningful for urban microclimate analyses and urban planning research.