甘肃瓜州锁阳城南雅丹地貌区起沙风况与输沙势特征

Based on the positioning meteorological observation data from 2016 to 2018, the sand - blowing wind conditions and the changes in sand transport potential in the Yardang landform area south of Suoyang City in Guazhou, Gansu were analyzed. The results show that: (1) The sand - blowing winds in the study area are composed of two groups of winds with approximately opposite directions. The main wind direction is NE - E, accounting for 68.86% of the annual sand - blowing winds, and the secondary wind direction is WSW - WNW, accounting for 27.67%; (2) The annual average frequency of sand - blowing winds is 19.0%. The frequencies of sand - blowing winds are the highest in spring and summer, accounting for 33.57% and 34.69% of the whole year respectively, and the distribution characteristics of sand - blowing wind directions in each season are basically the same; (3) The wind regime type in the study area is a blunt bimodal wind regime with a high wind energy environment and a medium wind direction variability. The magnitude and direction variability of the sand transport potential have obvious seasonality. The total sand transport potential (DP) and the resultant sand transport potential (RDP) are higher in spring and summer, and the value of the direction variability RDP/DP is higher in summer and winter. The resultant sand transport direction (RDD) is 245.45° - 253.01° (WSW); (4) The long - axis trend of the Yardang landform in the study area is consistent with the main sand transport direction, indicating that wind power is the main dynamic condition for its formation.

以2016—2018年定位气象观测数据为依据,分析了甘肃瓜州锁阳城南雅丹地貌区的起沙风况及输沙势变化情况。结果表明: (1)研究区起沙风由两组风向近似相反的风所组成,主风向为NE-E,占全年起沙风的68.86%,次风向为WSW-WNW向,占27.67%; (2)年平均起沙风频率为19.0%,春季和夏季起沙风频率最高,分别占全年的33. 57%和34.69%,各季起沙风向分布特征基本一致; (3)研究区风况类型为高风能环境和中等风向变率的钝双峰型风况。输沙势的大小和方向变率具有明显的季节性,春、夏季的总输沙势(DP)和合成输沙势(RDP)较高,夏季和冬季的方向变率RDP/DP值较高,合成输沙方向(RDD) 245.45° ~ 253.01°(WSW) ; (4)研究区雅丹地貌长轴走向与主输沙方向一致,说明风力是其形成的主要动力条件。