Impacts of urban morphology on typhoon-induced wind hazards at the pedestrian level

Abstract

Typhoon-induced wind hazards are uncertain and extreme within urban neighborhoods at the pedestrian level. Previous studies lacked of effective assessment methods. In this study, typhoon Mui-fa (2022) event over Lujiazui Financial Center in Shanghai was simulated using the Weather Research and Forecasting (WRF) model coupled with the Parallelized Large-Eddy Simulation Model (PALM), then the pedestrian distress indicators (Gust Factor (GF) and Speeding-up Efficacy (SE)) were calculated for describing local risks. The findings suggest that there are positive correlations between urban morphological parameters and pedestrian distress indicators, with λp (building area fraction) exhibiting the best correlations. This indicates that λp can be regarded as effective parameter for wind safety assessment. Meanwhile, the probability density functions (PDFs) of GF and SE constructing by λp can establish the connections between the extreme at specific probabilities and the average. With the increase of λp, these PDFs exhibit a slow rightward shift of the peak and a rapid broadening of the distributions. The assessment method valuable to typhoon-prone coastal cities in the field of practical engineering applications.