Reasonable building height distribution in urban residential areas is conducive to smoother vertical airflow exchange and promotes sustainable development. This paper studies the influence of building layouts on vertical ventilation in high-rise residential areas in Harbin, China, and discusses typical building layout objectives. The ideal area of 220 × 220 m was determined using statistical analysis and specification requirements, and seven typical layouts were defined based on the distribution of building heights. The computation fluid dynamics (CFD) simulation was verified using wind tunnel testing to improve the accuracy of the Phoenics simulation software. Wind speed, wind pressure, and the Universal Thermal Climate Index (UTCI) in residential areas distributed at different heights were analyzed and evaluated. The results indicated that the Phoenics simulation parameter settings, verified via wind tunnel testing, could achieve reasonable simulation results and different height distribution modes had an impact on the changes in wind speed and wind pressure. The equal-height layout that conformed to the row spacing of the buildings and the layout of taller buildings on the east side could provide higher comfort, and did not require enclosed and downwind layouts. This research can inform the green and livable design of residential buildings and provide a new perspective for the construction of high-rise residential areas in cold cities.

This research addresses urban heat island intensification driven by urbanization using Dianchi Lake in Kunming, China, as a case study, aiming to quantitatively evaluate the spatial extent, intensity, and land cover sensitivity differences in the cooling effects of large urban water bodies across dry/wet seasons and complex urban landscapes (forest, cropland, and impervious surfaces) to provide a scientific basis for optimizing thermal environments in low-latitude plateau cities. Based on Landsat 8/9 satellite data from dry (January) and wet (May) seasons in 2020 and 2023 used for land surface temperature (LST) retrieval combined with land use data, buffer zone gradient analysis was adopted to quantify the spatial heterogeneity of key cooling indicators within 0–1500 m lakeshore buffers. The results demonstrated significant seasonal differences. The wet season showed a greater cooling extent (600 m) and higher intensity (6.0–6.6 °C) compared with the dry season (400 m; 2.4–3.9 °C). The land cover responses varied substantially, with cropland having the largest influence (600 m), followed by impervious surfaces (400 m), while forest exhibited a minimal effective cooling range (100 m) but localized warming anomalies at 200–400 m. Sensitivity analysis confirmed that impervious surfaces were the most sensitive to water-cooling, followed by cropland, whereas forest showed the lowest sensitivity.

Passages between buildings comprise the airflow path through the buildings, and the wind passage is often studied in terms of two buildings located parallel or at a certain angle. From the perspective of urban areas, the wind passage can be considered the series connection of all local wind passages between each row of buildings. Whether the central axis of each local wind passage is collinear or not, the wind passages of the building array can be summarized as distorted and streamlined types. Large-eddy simulations (LESs) are employed to assess the impacts of the above two wind passage types on the airflow and drag characteristics. The mean, unsteady flow fields and the drag distributions are discussed to assess the effects of wind passages types. Span-wise airflow was found in the wake region in the case of distorted wind passages (DWP), whereas the recirculating vortices dominated the wake region for the case of streamlined wind passages (SWP). Span-wise airflow enhanced the mean stream-wise velocity U and span-wise velocity U in the wake region, decreased U in the wind passage region, and increased dispersive stress $〈{\tilde{V}}^2〉$ and $〈{\tilde{U}}^2〉$ within the urban canopy and the peak Reynolds stress above the urban canopy. Further, it strengthened the individual drag forces of buildings and the fluctuations of span-wise and stream-wise individual drag forces. The air of DWP penetrated deeper than SWP. These findings provide theory and data support for better design of wind passages between buildings and may serve as a foundation for urban design and planning.

With the acceleration of urbanization, the problem of the urban heat island effect has become increasingly prominent, seriously impacting on the quality of life and health of urban residents. This study used mobile observation method to measure the thermal environment of the street canyon in Kunming's Chenggong District. And select nine street samples with similar lengths to analyze the impact of street canyon orientation and aspect ratio on the thermal environment. Results show that in the morning, north-south oriented streets are about 1.5 °C warmer than east-west oriented streets with the same aspect ratio. In the afternoon hightemperature period, the north-south oriented streets are about 0.9 °C cooler than the east-west oriented ones, indicating better thermal comfort for north-south oriented street canyons compared to east-west oriented ones. Additionally, the relationship between the street aspect ratio and street temperature is associated with solar irradiation, showing a positive correlation in the morning and a negative correlation in the afternoon, with this correlation also being influenced by the street orientation. This study provides a scientific basis for livable urban planning and the optimization of urban microclimate environments.