毛乌素沙地不同下垫面的风沙运动特征

摘要/Abstract

摘要： 基于野外实地观测,研究了毛乌素沙地不同下垫面的风沙运动特征。平坦流沙地上的风速随高度呈对数分布; 沙丘上的风速梯度在高度上的变化随植被盖度增大而增强; 相近风速下,0~60 cm高度范围内的输沙强度从大到小依次为流动沙丘丘顶＞平坦流沙地＞半流动沙丘丘顶＞裸露黄土梁地＞黄土梁翻耕地＞玉米留茬地＞半固定沙丘丘顶。同一植被盖度下,沙丘顶部输沙率随风速增加而增大,粗糙度随风速增加而减小。当风速小于起沙风速时,粗糙度随植被盖度的增加而增大; 当风速大于起沙风速时,平坦流沙地和沙丘顶部的粗糙度随风速增大有增加趋势,产生这种现象的可能原因是跃移层沙物质对气流的阻力随风速增大而增大。根据各类沙源地的起沙强度和总面积,风沙灾害防治的重点是植被盖度较小的沙地和黄土梁地。

关键词: 风速廓线, 风沙流结构, 输沙率, 粗糙度, 毛乌素沙地

Abstract: Aeolian movement characteristics over different underlying surfaces in Mu Us Sandy Land was researched based on field measurement. The results showed that wind profile over flat drifting sand followed logarithmical rule against height. Under similar wind-speed, the sediment discharge intensity within 0~60 cm successively distributed as mobile dune top>flat drifting sand>semi-mobile dune top>bare loess flat-topped ridge>dumped loess cropland land>maize stubble land>semi-mobile dune top. At given vegetation coverage, sand transport rate over dune top increased as wind-speed increased, roughness decreased as wind-speed increased. When wind speed was below the threshold sand-blowing wind speed, roughness increased as vegetation coverage increased; When wind speed was above the threshold, roughness over flat drifting land and dune top showed a increasing trend with wind speed. This may result from increasing sands saltation resistance to airflow when wind speed increased. Judging from sand-blown density and total area of underlying surface, key areas of sand disaster prevention lie in sandy land and loess flat-topped ridge with low vegetation coverage.

Key words: wind profile, sand flow structure, sand transport rate, roughness, Mu Us sandy land

中图分类号:

X169

吴晓旭;邹学勇*;王仁德;赵婧妍;程宏;钱江. 毛乌素沙地不同下垫面的风沙运动特征[J]. 中国沙漠, 2011, 31(4): 828-835.

WU Xiao-xu;ZOU Xue-yong;WANG Ren-de;ZHAO Jing-yan;CHENG Hong;QIAN Jiang. Aeolian Movement Characteristics over Different Underlying Surfaces in Mu Us Sandy Land[J]. JOURNAL OF DESERT RESEARCH, 2011, 31(4): 828-835.

参考文献

[1]陈隆亨.黑河下游地区土地荒漠化及其治理[J].自然资源,1996,2:35-43.
[2]Bagnold R A.The Physics of Blown Sand and Desert Dunes[M].New York:William Morrow & Company,1941:265.
[3]McEwan I K,Willetts B B.Numerical model of the salutation cloud[J].Acta Mechanica,1991,(Suppl.1):53-69.
[4]Dong Z B,Fryrear D W,Gao S Y.Modeling the development of sand transport[J].Soil Science,1999,12:930-935.
[5]Dong Z B,Gao S Y,Fryrear D W.Drag coefficients and roughness length as disturbed by artificial standing vegetation[J].Journal of Arid Environments,2001,49(3):485-505.
[6]Aderson R S,Haff P K.Wind modification and bed response during salation of sand in the air[J].Acta.Mech,1991(Suppl.1):21-25.
[7]王洪涛,董治宝,钱广强,等.关于风沙流中风速廓线的进一步实验研究[J].中国沙漠,2003,23(6):721-724.
[8]Bauer B O,Houser C A,Nicking W G.Analysis of velocity profile measurements from wind tunnel experiments with saltation[J].Geomorphology,2004(59):81-98.
[9]Kang L Q,Guo L J,Guo Z M,et al.Wind tunnel experimental investigation of sand velocity in Aeolian sand transport[J].Geomorphology,2008(97):438-450.
[10]Choi E C C.Field measurement and experimental study of wind speed profile during thunderstorms[J].Journal of wind engineering,2004,92(3-4):275-290.
[11]Li Z S,Ni J R,Mendoza C.An analytic expression for wind-velocity profile within the saltation layer[J].Geomorphology,2004,60(3-4):359-369.
[12]雷怀彦,林炳煌,刘建辉,等.福建东部海岸风沙流结构特征及沙害防治对策[J].华侨大学学报(自然科学版),2008,29(1):143-147.
[13]张伟民,汪万福,张克存,等.不同沙源供给条件下砾石床面的风沙流结构与蚀积量变化风洞试验研究[J].中国沙漠,2009,29(6):1015-1010.
[14]夏建新,石学峰,吉祖稳.植被覆盖条件下地表输沙率模型[J].应用基础与工程科学学报,2006,14(2):218-227.
[15]R A拜格诺.风沙和荒漠沙丘物理学[M].钱宁译.北京:科学出版社,1959:57-65.
[16]拓万权,杨根生.流动沙丘表面输沙率的理论计算方程[J].干旱区资源与环境,1996,10(4):50-54.
[17]Wolfe S A,Nickling W G.The protective role of sparse vegetation in wind erosion[J].Progress in Physical Geography,1993,17(1):50-68.
[18]Wasson R J,Nanniga P M.Estimating wind transport of sand on vegetated surfaces[J].Earth Surface Process and Landforms,1986,N(11):505-514.
[19]Buckley R.The effect of sparse vegetation on the dune sand by wind[J].Nature,1987,325:426-428.
[20]Landcaster N,Baas A.Influence of vegetation cover on sand transport by wind:Field studies at Owens Lake,Califonia[J].Earth Surface Processes and Landforms,1998,23:69-82.
[21]黄富祥,牛海山,王明星,等.毛乌素沙地植被覆盖率与风蚀输沙率定量关系[J].地理学报,2001,56(6):700-710.
[22]程皓,李霞,侯平,等.塔里木河下游不同覆盖度灌木防风固沙功能野外观测研究[J].中国沙漠,2007,27(6):1022-1026.
[23]Livingstone I,Wiggs G F S,Weaver C M.Geomorphology of desert sand dunes:A review of recent progress[J].Earth-Science Reviews,2007,80(3-4):239-257.
[24]马士龙,丁国栋,罗俊宝,等.沙蒿植被粗糙度动力学特性的检验与研究[J].水土保持研究,2006,13(1):86-88.
[25]董治宝,Fryrear D W,高尚玉.直立植物防沙措施粗糙特征的模拟实验[J].中国沙漠,2000,20(3):260-263.
[26]慕青松,王建成,苗天德.粗糙度动力学特性的初步研究[J].力学学报,2003,35(2):129-134.
[27]张雅静,申向东.植被覆盖地表空气动力学粗糙度与零平面位移高度的模拟分析[J].中国沙漠,2008,28(1):21-26.
[28]杨永梅,杨改河,冯永忠,等.毛乌素沙漠化过程探析[J].西北农林科技大学学报(自然科学版),2006,34(9):103-108.
[29]刘爱民,刘玉平,慈龙骏.毛乌素沙区的气候变化及人为活动特征分析[J].干旱区资源与环境,1996(4):8-18.
[30]李新荣.毛乌素沙地荒漠化与生物多样性的保护[J].中国沙漠,1997,17(1):58-62.
[31]李容全,朱国荣,张本.蒙陕交界地区风沙活动规律及其防治[J].北京师范大学学报(自然科学版),1995,31(2):251-258.
[32]王翔宇,朴东均,丁国栋,等.流动沙丘风沙流结构的定量研究[J].水土保持研究,2008,15(2):36-39.
[33]廖空太,李耀辉,刘虎俊,等.库姆塔格沙漠羽毛状沙垄风沙活动强度特征[J].中国沙漠,2008,28(3):399-405.
[34]何清,谬启龙,张瑞军,等.塔克拉玛干沙漠肖塘地区空气动力学粗糙度分析[J].中国沙漠,2008,28(6):1011-1016.
[35]王升堂,赵延治,邹学勇,等.北京郊区不同土地利用类型起沙起尘的特征研究[J].地理科学,2005,25(5):601-605.
[36]马全林,王继和,张景光,等.流动沙丘先锋植物沙米的生态防护作用[J].水土保持学报,2008,22(1):140-150.
[37]杨明元.对地表粗糙度测定的分析与研究[J].中国沙漠,1996,16(4):383-386.
[38]吴正等.风沙地貌与治沙工程学[M].北京:科学出版社,2003:23-24.