Large scale sand saltation over hard surface:a controlled experiment in still air  

作　　者：LIU Benli WANG Zhaoyun NIU Baicheng QU Jianjun 

机构地区：[1]Key Laboratory of Desert and Desertification,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China [2]Research Station of Gobi Desert Ecology and Environment in Dunhuang of Gansu Province,Lanzhou 730000,China [3]University of Chinese Academy of Sciences,Beijing 100049,China [4]Qinghai Normal University,Xining 810004,China

出　　处：《Journal of Arid Land》2021年第6期599-611,共13页干旱区科学（英文版）

基　　金：supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XD23060201);the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(GML2019ZD0601);the National Natural Science Foundation of China(42071014);the Excellent Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y202085)。

摘　　要：Saltation is the major particle movement type in wind erosion process.Saltating sand grains can rebound up to tens of times larger in length and height over hard surface(such as gravel surface)than over loose sand surface.Gravels usually have different faces,causing distinct response of the impacting grains,but the effects of the grain and gravel-surface contact angle on grain rebound are not yet well quantified.We performed full-range controlled experiments of grain saltation using different contact angles,grain sizes and impact speeds in still air,to show that contact angle increases the height of representative saltation path but decreases particle travel length.The results were compared with outputs from the COMprehensive numerical model of SALTation(COMSALT).Large saltation height of 4.8 m and length of 9.0 m were recorded.The maximum and representative saltation height over the gravel surface were found to be about 4.9 times and 12.8 times those over the loose sandy surface,respectively.The maximum saltation length may be reduced by 58%and the representative saltation height may be increased by 77%as contact angle increases from 20°to 40°.We further showed that the collision inertia contributes 60%of the saltation length,and wind contributes to the other 40%.These quantitative findings have important implications for modeling saltation trajectory over gravel surface.

关 键 词：sand saltation TRAJECTORY gravel surface contact angle full-scale experiment 

分 类 号：P931.3[天文地球—自然地理学]