Observational Research on the Quantitative Influence of the Complex Underlying Surface of the City on Local Air Temperature and Wind

To comprehensively explore the local differences of urban microclimates, a one-year observational experiment was conducted utilizing a smart micro weather station in the urban area of Mentougou, Beijing, China. The local climate zoning was implemented to analyze the effects of the local environment on the near-surface temperature and wind field. The results demonstrated the following: (1) Daytime temperature is governed by solar radiation, building shading, land use, and anthropogenic heat emissions. On the other hand, night temperature is primarily influenced by urban canopy characteristics as well as anthropogenic heat emissions (traffic, life). The average daily temperature in summer is 0.68°C higher in the middle-level dense plots and 0.66°C higher in winter in the high-level dense plots (compared with sparse building plots, the same below). The cooling effect of dense tree plots in summer (0.3°C) is stronger than in winter (0.07°C). The cooling effect of the water body is primarily reflected during the summer days, which is 0.29°C lower on average, while in winter, the water body is predominantly warmed with a daily average of 0.38°C higher. (2) Due to the low roughness of the water block, the daily average wind speeds in summer and winter are higher by 0.5 and 0.37 m/s, respectively. On the other hand, the effects of wind barriers can be attributed to the reduced daily average wind speeds in summer and winter by 0.13 and 0.23 m/s, respectively. Owing to the blocking effect of buildings, the average daily wind speed of the middle-level dense plots is 0.54 and 0.48 m/s lower in summer and winter, respectively. This paper reveals the quantitative impact of urban complexes on local air temperature and wind. Research shows that local climate zoning can better reflect the local differences in temperature and wind in urban blocks and provide a scientific basis for the construction of livable cities.