摘要
利用科尔沁沙地西部响水河河岸沙丘近地层风速观测资料,探讨了典型河岸沙丘背风坡的风速脉动特征。结果表明:(1)河岸沙丘丘顶最大风速脉动值为5.3 m·s^(-1),其风速脉动强度随高度的增加呈波动增加趋势,湍流度随高度增加呈减小趋势,但变幅较小,而风向脉动幅度极小。(2)河岸沙丘背风坡脚最大风速脉动值为7.8 m·s^(-1),其风速脉动强度也有随高度增加而波动增加的趋势,但因背风坡形态突变形成的“次生流”(反向涡旋气流)影响,背风坡脚湍流度随高度的增加变化较小且属高强度湍流,其风向脉动幅度较大。(3)河岸沙丘丘顶和背风坡脚的风速脉动值在随高度的变化和时间系列上均具有一致性(同步增大或减少),但风速脉动无明显周期性规律。河岸沙丘丘顶平均风速和风速脉动强度均大于背风坡脚,但最大风速脉动值、湍流度和风向脉动则反之。
Based on the observation of wind speed at Xiangshui riverine dune in the west of Horqin Sandy Land,characteristics of wind speed fluctuation at leeward slope of typical riverine dune were discussed.The results are as follows.(1) The maximum wind speed fluctuation value at the top of the riverine dune is 5.3 m·s~(-1),and the wind speed fluctuation intensity has a trend of increasing with increasing height from the surface.Although the turbulence decreases with increasing height from the surface,the amplitude is small,and the wind direction fluctuation is very small.(2) The maximum wind speed fluctuation value at the foot of the leeward slope of the riverine dune is 7.8 m·s~(-1),and the wind speed fluctuation intensity also has a trend of increasing with increasing height from the surface.The turbulence on the foot of the leeward slope changes little with increasing height from the surface,and it belongs to high intensity turbulence and its wind direction fluctuation is also very large.(3) The wind speed fluctuation values at the top and foot of the leeward are consistent(increasing or decreasing simultaneously) with height changes and time series,but there is no obvious periodicity.The average wind speed and wind speed fluctuation intensity on the top of the riverine dune are greater than the leeward slope foot,but the maximum wind speed fluctuation value,turbulence and wind direction fluctuation are reversed.
作者
杨林
韩广
王勇
李航飞
陈世发
YANG Lin;HAN Guang;WANG Yong;LI Hang-fei;CHEN Shi-fa(College of Tourism and Geography,Shaoguan University,Shaoguan 512005,China;College of Geographic Science,Hunan Normal University,Changsha 410081,China;Institute of Geographical Science,Henan Academy of Sciences,Zhengzhou 450052,China)
出处
《湖南师范大学自然科学学报》
CAS
北大核心
2023年第3期113-118,共6页
Journal of Natural Science of Hunan Normal University
基金
国家自然科学基金资助项目(42101008,41271025)。
关键词
河岸沙丘
风速廓线
风速脉动
风向脉动
科尔沁沙地
riverine dune
wind profiles
wind velocity fluctuation
wind direction fluctuation
Horqin Sandy Land
