Against the backdrop of global warming and rapid urbanization, high-density central urban areas in valley cities face exacerbated ventilation deterioration and reduced pedestrian-level wind comfort due to topographic constraints and intensive development. This study investigates the coupling mechanism between spatial morphology and wind environment in Lanzhou’s Xiguan Cross area using a complex network model, CFD numerical simulation, and statistical analysis. A ventilation resistance surface was constructed using circuit theory and ArcGIS 10.8 to identify ventilation corridors. PHOENICS was used to simulate summer pedestrian-level (1.5 m) wind fields, while SPSS 2025 was employed for regression analysis of building density, enclosure degree, and dispersion degree against the mean wind velocity ratio. Results indicate: (1) wind velocities are higher at the periphery and lower in the interior; (2) building density and enclosure degree have a highly significant negative impact on the wind velocity ratio, whereas dispersion degree has a significant positive impact, with influence intensity ranked as enclosure degree > building density > dispersion degree. Based on these findings, three differentiated morphological optimization strategies are proposed and validated through simulation, effectively increasing the proportion of comfortable wind zones. This study provides a scientific basis for improving urban microclimate and pedestrian comfort through urban design.

High-density valley residential areas face poor ventilation and heat island effects. Taking Lanzhou’s Xin’an Residential Area as a case, this study integrates land use and cover change (LUCC), circuit theory, and CFD to construct a resistance surface, identify corridors and key nodes, reveal coupling mechanisms and propose collaborative optimization strategies. Results show the following: (1) Ventilation resistance presents a pattern of “low in the north, high in the south, permeable at the periphery, obstructed in the interior”, with high-resistance zones accounting for 18% of the grid area; green plot ratio is the most sensitive regulatory factor (standardized regression coefficient = −0.679). (2) The fishbone-like ventilation network has primary hub nodes undertaking 80% of airflow transport, while tertiary terminal nodes (73% of total nodes) are the main ventilation bottlenecks. (3) Built-up land morphological indicators show strong spatial collinearity, and the positive effect of road plot ratio is masked in the regression model. The proposed hierarchical micro-renewal strategy provides an operable technical pathway for wind environment optimization, low-carbon renewal and climate-adaptive retrofitting of high-density valley residential areas. This study extends circuit theory to micro-scale ventilation analysis and establishes a replicable quantitative framework for ventilation diagnosis in analogous valley residential contexts.

Land-intensive high-density residential development often comes at the cost of compromised natural ventilation efficiency and reduced capacity for urban heat island mitigation, and such trade-offs are particularly pronounced in valley cities due to topographical constraints. Taking Lanzhou Yineng Huanghe Jiayuan as a case study, this research constructs a “Source-Flow-Sink” landscape ventilation efficiency measurement framework based on circuit theory and CFD numerical simulation. Combined with correlation analysis and multiple linear regression, the coupling mechanism between spatial morphology and ventilation efficiency is examined. The results indicate that: (1) The study area exhibits a ventilation pattern characterized by “Source” in the north, “Flow” in the middle, and “Sink” in the south; (2) The wind speed ratio in the residential area shows a highly significant negative correlation with vegetation coverage, and a significant negative correlation with building dispersion and average building height; (3) Based on three configuration modes of “Source-Flow-Sink”, differentiated micro-renewal strategies that do not alter the core indicators of land intensification are proposed, providing a scientific basis for climate-adaptive design of intensive residential areas in valley cities.

To address the mismatch between spatial form and wind environment of residential districts in cold-region valley-type cities, which leads to poor thermal comfort, low ventilation efficiency and high building energy consumption, this study takes Hongyun Runyuan, a typical large-scale residential district in Lanzhou, as the research case. Using orthogonal experimental design, nine spatial schemes were developed with three core morphological parameters (building orientation, spacing coefficient, enclosure degree), each set with three levels. CFD simulations via PHOENICS were performed to analyze the influence weight of each parameter on the winter wind environment at 1.5 m pedestrian height. Results show that building orientation exerts an extremely significant effect on the winter wind environment (p = 0.006), while the spacing coefficient and enclosure degree have no significant independent effects (all p > 0.05). The optimal scheme, featuring 10° east of south orientation, 1.1 spacing coefficient and 0.3 enclosure degree, can effectively meet the winter wind protection demand. The quantitative optimization strategies proposed in this study provide scientific support for wind-friendly residential planning and building energy efficiency improvement in cold-region valley-type cities.

Amid global urban transition from sprawling expansion to stock-oriented regeneration, exploring the spatiotemporal heterogeneity and mechanisms of urban spatial vitality in old urban areas is crucial for advancing sustainable urban renewal and enhancing human well-being. This study builds a built environment index system, taking the old urban areas of Wuwei City, China, as a case study, and employs the MGWR model to analyze spatial vitality and its drivers. Results show: (1) Diverse functional elements exhibit significant spatiotemporal variations, with basic living facilities having stable impacts, while cultural and catering facilities show morning local agglomeration and nighttime region-wide driving effects, respectively. (2) Regarding accessibility, the road network is a key spatial factor. It shows a positive statistical association with regional vitality during the day, but may correlate with traffic and environmental stress at night. This indicates a potential trade-off between commercial activity and residential comfort across different time periods. (3) Spatial quality elements show strong spatial stability. Specifically, floor area ratio and open space ratio exhibit positive statistical associations with vitality, while building density and height tend to show negative correlations. This may reflect structural bottlenecks imposed by high-density development on sustainable living spaces. (4) Strategies like micro-functional layouts, day-night differentiated traffic networks, and spatial chassis optimization are proposed to provide quantitative evidence for sustainable stock-oriented regeneration, balancing heritage conservation with modern urban vitality.