Analysis of Valley Wind Circulation Characteristics in the Guyangshu Winter Olympics Competition Area Under Complex Terrain

ZHANG Xiaorui; Tian Zhiguang; LI Zhenghao; HUANG Zhaochu; ZHU Gang; LI Xiliang

doi:10.16032/j.issn.1004-4965.2025.024

Abstract：This study investigates the dynamics and characteristics of air flow in the Guyangshu competition area by analyzing intensive observation of automatic weather stations and ERA5 reanalysis data collected in the Winter Olympics field from 2017 to 2020.Considering its distinct topography and the context of atmospheric circulation,wind vector averaging and composite analysis methods are employed to improve analyses.Results indicate that the Guyangshu competition area is highly influenced by terrain and thermal effects,resulting in significant differences in terrain wind characteristics.Daytime wind directions are relatively scattered,with speeds mostly below 4-5 m·s-1.At night,wind directions are more concentrated,and speeds are generally below 2-3 m·s-1.Within the same competition venue,stations dominated by down-slope winds have lower wind speeds,mainly below 1-2 m·s-1,compared to those dominated by down-valley winds.Under weak cold air conditions,wind direction shifts typically occur around 08:00 in the morning and between 17:00-19:00 in the evening.The transition period averages 1.5-2 hours,with the timing and duration of these changes are significantly influenced by solar radiation.As the wind direction changes,wind speeds first decrease and then increase.In the winter competition areas,the lowest average daily wind speeds are observed around 09:00,while peak average daytime wind speeds are observed between 12:00 and 14:00.In off-road competition zones,the highest daily average wind speeds are recorded between 12:00 and 15:00.The average daily wind speeds at each station correlate with the terrain's wind scale in their locations,with stations influenced by valley winds often have higher speeds than those affected by slope winds.