关键词: 河谷地形, 狭管效应, 阵风系数, 风廓线指数

Abstract: We select three meteorological stations and six automatic weather stations which are located along the three gorges valley (in Hubei Province) nearby Xiangxi Yangtze River Highway Bridge (Guojiaba meteorological station). We collected wind speed and wind direction data for comparative analysis, and analyzed the different influence of wind speed in different regions of the valley. The results showed that, in the horizontal direction, the three automatic weather stations of Yandunbao, Guojiaba and Miaobao are near the river, presenting an obvious funnel effect, where average wind speeds are larger, and the frequencies of high-value of maximum wind speed and extreme wind speed increase. The rest of stations located not near the river are affected by the local terrain where average wind speeds are smaller, maximum wind speed and extreme wind speed in large frequency are low; In the vertical direction, the wind speed under 150 meters not change in height, the measured wind-profiling index is approximately zero; At the location of bridge, the value of gust factor is 1.56 where gustiness is strong.

Key words: Valley terrain, funnelling, gust factor, wind-profiling index