沙粒胶结体(sand cemented bodies,缩写为SCB)是由众多沙粒胶结而成的大颗粒物质,广泛分布于塔克拉玛干沙漠腹地部分垄间地表。通过风洞实验测定了不同风速下不同粒径沙粒胶结体覆盖对沙床面的土壤风蚀率和输沙率变化的影响。结果表明:风速和粒径是影响SCB覆盖沙床面风蚀率的主要因素。在一定的风力条件下,风蚀率随沙粒胶结体粒径的增加呈指数递减变化,在一定的胶结体覆盖度下,风蚀率随风速增加而增大,且粒径越大风蚀率随风速的增加而增大的趋势更为明显;风速不是影响地表输沙率的主要因素,胶结体粒径在一定程度上对输沙率的影响起主导作用。随着胶结体粒径的增加,沙粒在胶结体覆盖床面产生上升过程,且输沙率随粒径的增加而增大,胶结体覆盖对输沙率的抑制作用主要体现在胶结体覆盖的密度效应上,密度越小输沙率越高。即同一盖度下的胶结体颗粒物,大粒径的胶结体较小粒径胶结体沙床面分布密度、数量都相对较小。因此,大粒径胶结体地表输沙率相对较大。不同粒度范围的胶结体覆盖沙床面表现出不同的风蚀和输沙率抑制效应,依次为:2~3 mm<3~5 mm<5~7 mm<7~10 mm<10 mm。
Sand cemented bodies (SCB) were extensively distributed in the hinterland of the Taklimakan Desert. In this study, the effects of SCB with different sizes on restraining aeolian erosion and windblown sand discharge were researched by wind tunnel simulation. Results showed that wind velocity and SCB size were the main factors affecting aeolian erosion. Under certain wind conditions, aeolian erosion restraint rate was decreased exponentially with the increase of SCB size. Under a certain SCB coverage, wind erosion rate was increased with the increase of wind velocity, and the bigger the SCB size was, the more obvious the increase trend of wind erosion with the increase of wind velocity would be. SCB size was the dominant factor affecting the surface windblown sand discharge, but not wind velocity. With the increase of SCB size, there was a rising process of sand grains on the SCB mulch bed, and the windblown sand discharge was increased with the increase of SCB size. The effect of SCB mulch bed in restraining the windblown sand discharge was mainly reflected by SCB density, and the lower the coverage was, the higher the windblown sand discharge would be. At the same SCB coverage, the distribution density and number of the large-sized SCB were lower than those of small-sized SCB. Therefore, the surface windblown sand discharge was relatively high. The restraint of SCB with different sizes to wind erosion and windblown sand discharge was in an order of 2-3 mm<3-5 mm<5-7 mm<7-10 mm<10 mm.
〔1〕 吴正.风沙地貌学〔M〕.北京:北京科学出版社,1987.〔Wu Zheng.Aeolian Geomorphology〔M〕.Beijing:Science Press,1987.〕
〔2〕 王志强,富宝锋,何艺峰,等.砾石覆盖对土壤风蚀防护效率的风洞模拟研究〔J〕.干旱区资源与环境,2014,28(9):90-93.〔Wang Zhiqiang,Fu Baofeng,He Yifeng,et al.Wind tunnel simulation on protective efficiency of gravel mulch on soil erosion〔J〕.Journal of Arid Land Resources and Environment,2014,28(9):90-93.〕
〔3〕 刘连友,刘玉璋,李小雁,等.砾石覆盖对土壤吹蚀的抑制效应〔J〕.中国沙漠,1999,19(1):60-62.〔Liu Lianyou,Liu Yuzhang,Li Xiaoyan,et al.Effect of gravel mulch restraining soil deflation by wind tunnel simulation〔J〕.Journal of Desert Research,1999,19(1):60-62.〕
〔4〕 王训明,郎丽丽,花婷,等.戈壁砾石覆盖度与风蚀强度关系实验研究〔J〕.中国沙漠,2013,33(2):313-319.〔Wang Xunming,Lang Lili,Hua Ting,et al.Gravel cover of Gobi desert and its significance for wind Erosion:An experimental study〔J〕.Journal of Desert Research,2013,33(2):313-319.〕
〔5〕 张克存,张伟民,屈建军,等.不同砾石盖度戈壁床面动力学特征研究〔J〕.干旱区研究,2012,29(6):1 077-1 082.〔Zhang Kecun,Zhang Weiming,Qu Jianjun,et al.Study on dynamic properties of Gobi surface with different gravel coverage〔J〕.Arid Zone Research,2012,29(6):1 077-1 082.〕
〔6〕 张伟民,谭立海,张克存,等.不同砾石覆盖度床面蚀积过程的野外风洞实验研究〔J〕.地理科学,2012,32(11):1 370-1 376.〔Zhang Weiming,Tan Lihai,Zhang Kecun,et al.Field wind tunnel simulation of the process of aeolian erosion and deposition of gravel beds with different coverage〔J〕.Scientia Geographica Sinica,2012,32(11):1 370-1 376.〕
〔7〕 杨东亮,王雪芹,胡永锋,等.风沙流输沙通量垂向分布研究——以塔克拉玛干沙漠南缘流沙地表风沙流观测为例〔J〕.中国沙漠,2012,32(3):631-639.〔Yang Dongliang,Wang Xueqin,Hu Yongfeng,et al.Vertical distribution of aeolian sand mass flux based on field observation at southern rim of Taklimakan Desert〔J〕.Journal of Desert Research,2012,32(3):631-639.〕
〔8〕 李生宇,孙娜,马学喜,等.塔克拉玛干沙漠腹地垄间砂粒胶结体的基本特性及研究价值〔J〕.中国沙漠,2016,36(2):265-273.〔Li Shengyu,Sun Na,Ma Xuexi,et al.The characteristics and significances of the sand cemented bodies discovered on inter-dune corridor in central Taklimakan Desert〔J〕.Journal of Desert Research,2016,36(2):265-273.〕
〔9〕 郑则浩,雷加强,李生宇,等.可移动式环境风洞气动特性测试与评价〔J〕.中国沙漠,2012,32(6):1 551-1 558.〔Zheng Zehao,Lei Jiaqiang,Li Shengyu,et al.Test and evaluation of wind flow characteristics of a portable wind tunnel〔J〕.Journal of Desert Research,2012,32(6):1 551-1 558.〕
〔10〕孙娜,李生宇,马学喜,等.砾石级沙粒胶结体抗风蚀效益的实验研究〔J〕.中国沙漠,2016,36(4):2-6.〔Sun Na,Li Shengyu,Ma Xuexi,et al.Wind tunnel experiment on the anti-erosion benefits of gravel-sized cemented bodies discovered on inter-dune corridor in central Taklimakan Desert〔J〕.Journal of Desert Research,2016,36(4):2-6.〕
〔11〕王训明,董治宝,陈广庭.塔克拉玛干沙漠中部部分地区风沙环境特征〔J〕.中国沙漠,2001,21(1):56- 61.〔Wang Xunming,Dong Zhibao,Chen Guangting.Characteristics of blown sand environment in middle Taklimakan Desert〔J〕.Journal of Desert Research,2001,21(1):56- 61.〕
〔12〕董治宝,陈渭南,董光荣,等.关于人为地表结构破损与土壤风蚀关系的定量研究〔J〕.科学通报,1995,40(1):54-57.〔Dong Zhibao,Chen Weinan,Dong Guangrong,et al.About the artificial surface structure damage relations with the soil wind erosion quantitative research〔J〕.Chinese Science Bulletin,1995,40(1):54-57.〕
〔13〕Nickling W G,McKenna Neuman C.Development of deflation lag surfaces〔J〕.Sedimentology,1995,42:403-414.
〔14〕Tan L,Zhang W,Qu J,et al.Aeolian sand transport over gobi with different gravel coverages under limited sand supply:A mobile wind tunnel investigation〔J〕.Aeolian Research,2013,11:67-74.
〔15〕Logie M.Wind tunnel experiments on dune sands〔J〕.Earth Surface Processes and Landforms,1981,6:365-374.
〔16〕Nickling W G,Neuman C M.Development of deflation lag surfaces〔J〕.Sedimentology,1995,42(3):403-414.
〔17〕Raupach M R.Saltation layers,vegetation canopies and roughness lengths〔J〕.Aeolian Grain Transport1.Springer Vienna,1991,1 (Suppl.):83-96.
〔18〕Raupach M R,Gillette D A,Leys J F.The effect of roughness elements on wind erosion threshold〔J〕.Journal of Geophysical Research:Atmospheres,1993,98(D2):3 023-3 029.
〔19〕Gillies J A,Nickling W G,King J.Aeolian sediment transport through large patches of roughness in the atmospheric inertial sub layer〔J〕.Journal of Geophysical Research:Earth Surface,2006,(2003-2012) 111(F2).
