Field measurement analysis of wind profiles in mountainous terrain : focusing on periodic thermally-developed winds

Abstract

Periodic thermally-developed wind, generated by local thermal gradients, is one of the most frequent wind phenomena in mountainous terrains. Studying its wind profile is crucial for characterizing local wind fields. This study utilizes wind radars and automatic weather stations to conduct long-term measurements of wind characteristics at different heights onsite of a long-span bridge located in a deep-cut canyon and employs the correlation between the recorded wind speed and temperature to identify periodic thermally-developed wind events. Based on the identification result, the wind profiles of the periodic thermally-developed wind events are analyzed for their temporal and spatial characteristics and are systematically categorized into four stages. By extracting and analyzing the high wind speed profiles recorded in the mountainous terrains, it is revealed that the recorded wind profile differs significantly from traditional wind profiles in plain and coastal terrains. As a result, a new normalization wind speed profile model suitable for mountainous terrain is proposed using a wind speed threshold sliding sampling method, and a combined wind parameters profile model is constructed combined with the Copula and Inverse First-Order Reliability Method.