As China’s electricity demand continues to rise, the country increasingly relies on long-distance power transmission lines, particularly through the “West-to-East Electricity Transfer” project, to transport energy from resource-rich western regions to the densely populated east and south. However, the structural stability of these extensive networks is increasingly challenged by extreme wind events, yet the spatial variability and potential risk to transmission infrastructure remain poorly quantified at the national scale. In this study, we assess the spatiotemporal characteristics of extreme winds along nine major transmission lines from 1970 to 2019 using ERA5 reanalysis and in-situ meteorological observations and develop a potential risk index derived from normalized wind speed return periods to identify regions where transmission lines are most exposed to extreme wind hazards. The results reveal pronounced regional variations, with eastern Xinjiang, the Qaidam Basin, and the Inner Mongolia Plateau experiencing the strongest and most frequent high-wind events, particularly in spring and summer. Sustained high winds lasting 6 h occur more frequently than those lasting 12 h. Significant trends in extreme wind speeds were identified, with some regions (e.g., the Inner Mongolia Plateau) showing increases (up to 0.3 m s −1 per decade), while others, such as the Qaidam Basin, exhibiting decreases (up to −0.3 m s −1 per decade). Spatiotemporal analysis of two ultra-high-voltage transmission lines—Ruoqiang–Hubei and Badain Jaran–Chengdu—shows strong topographic modulation of wind extremes, with high winds concentrated in open basins and deserts but greatly reduced across complex terrains such as the Tibetan Plateau. Persistent wind–transmission line orthogonality in mountainous regions, however, corresponds to reduced impact due to wind speed attenuation. This research provides crucial insights for infrastructure design, emphasizing the importance of region-specific risk assessments.
Li et al. (2026) studied this question.