Urban wind environments are closely related to air pollution and outdoor human comfort. The urban natural ventilation potential (NVP) is an important factor in urban planning and design. However, for ventilation studies on urban scales, neither macroscale numerical simulations (i.e., WRF, MM5, etc.) nor microscale computational fluid dynamics (CFD) simulations can conduct efficient analyses. Based on the similarity between water flows and airflows, an efficient approach is proposed in this paper to map the urban NVP. Through integrating the urban terrain model, urban form model, and prevailing wind pressure model, an airflow digital elevation model (AF-DEM), which represents the resistance to airflow and can be used for a hydrological simulation, is generated and applied to evaluate the urban airflow patterns under different terrain, urban form and ambient wind conditions. The objective was to develop a simulation platform that can efficiently predict the distribution of natural ventilation corridor and NVP. The stream network calculated through the simulation is regarded as potential ventilation corridors within the city, and an index calculated from the coverage rate of wind corridors (CRW) is proposed for evaluating the relative NVP. Taking Nanjing as a case study, 8 AF-DEMs based on different wind directions and wind speed conditions are generated, and their corresponding ventilation corridor maps are constructed. The results are in good agreement with the empirical evidence, indicating that the hydrological model, though a rudimentary approximation of the actual airflows, was effective in revealing the natural ventilation corridor and characterize the relative NVP. Moreover, the implementation of this novel method is simple and convenient, and it has great application potential and value in urban design and management.

城市风环境与空气污染和室外人类舒适度密切相关。城市自然通风潜力（NVP）是城市规划和设计的重要因素。但是，对于城市规模的通风研究，无论是宏观数值模拟（即WRF，MM5等）还是微观尺度计算流体动力学（CFD）模拟都无法进行有效的分析。基于水流与气流之间的相似性，本文提出了一种有效的方法来绘制城市NVP。通过整合城市地形模型，城市形态模型和主要风压模型，生成了代表气流阻力并且可用于水文模拟的气流数字高程模型（AF-DEM），并将其应用于评估不同地形下的城市气流模式 城市形态和环境风况。目的是开发一个可以有效预测自然通风走廊和NVP分布的仿真平台。通过模拟计算得出的河流网络被视为城市内潜在的通风走廊，并提出了根据风道覆盖率（CRW）计算的指标来评估相对NVP。以南京为例，根据风向和风速条件，生成了8个AF-DEM，并建立了相应的通风通道图。结果与经验证据高度吻合，表明水文模型虽然是实际气流的基本估算，但在揭示自然通风通道和表征相对NVP方面是有效的。