Identifying ventilation corridors in a coastal mountainous city under multiple circulation scenarios: CFD-based mountain resistance parameterization and directional-consistency screening

Near-surface wind fields in subtropical coastal mountainous cities are often shaped by multiple circulation scenarios and pronounced local wind-direction bifurcation. Meanwhile, the aerodynamic effects of continuous mountainous terrain are difficult to represent using conventional morphological indicators developed for built-up areas, which may weaken the continuity and physical interpretability of identified ventilation corridors. Taking Shenzhen as a case study, this study proposes a scenario-based framework for identifying ventilation corridors. Non-rainfall samples were first screened using gridded observations derived from automatic meteorological stations, and summer non-rainfall days were classified into four circulation scenarios based on onshore/offshore wind proportions and day–night wind-direction reversal. A representative local wind direction was then synthesized for each scenario. Ventilation resistance in built-up areas was represented by the frontal area index, whereas mountain resistance was estimated using a computational fluid dynamics (CFD)-informed logistic regression model. Candidate least-cost paths were generated on scenario-specific resistance surfaces and screened using a normalized directional-consistency index to identify ventilation corridor skeletons. The results were evaluated using two complementary lines of indirect evidence: station-based associations between wind speed and near-surface air temperature, and land-use-stratified comparisons of Landsat-derived land surface temperature. The proposed method identifies corridor networks with clear directional relevance and physical interpretability under different circulation scenarios, providing methodological and quantitative support for ventilation-corridor planning.