Ventilation potential simulation based on multiple scenarios of land-use changes catering for urban planning goals in the metropolitan area

The consequences of urban sprawl and densification are rising surface temperatures and decreased ventilation, which trigger intense urban heat island (UHI) effects. Improving natural ventilation is key for mitigating UHI effects. If policymakers lack foresight into the land-use changes, it may lead to uncontrolled expansion, threatening ventilation potential. Thus, focusing on land-use changes for urban planning goals, this study innovatively proposed the ventilation potential (VPT) simulation by 2030 under scenarios of business as usual (BAU), rapid urban sprawl (RUS), farmland preservation (FLP), and forest preservation (FTP). A model built on the random forest was used to simulate VPT under multiple scenarios. The results indicated that: (1) VPT was mainly influenced by roughness length and land surface temperature gradient, compared to forest canopy density, elevation variation coefficient, and slope. (2) The VPT in 2030 differed considerably between scenarios. Areas with high VPT exhibited a significant declining trend. Spatially, the Fen River and mountainous regions showed high VPT, while the VPT in the northern and southern plains was relatively low. (3) In the FLP scenario, the area with extremely low VPT increased by 476.83 km2 from 2020 to 2030, which was 2.7 times that of the 2010-2020 period. It has a high and extremely high VPT of 1063.82 km2, second to the FTP scenario. (4) In the FTP scenario, the area with high and extremely high VPT decreased by 70.43 km2 and 109.28 km2, from 2020 to 2030. It had the largest area of high and very high VPT among all scenarios, covering 1123.3 km2. The model supports data updating as well as provides scalability of the indicators. With the refinement of this model, the study is expected to offer spatial forecasting tools for urban planning, guiding the development of livable environments in rapidly urbanizing cities to cope with climate change.