| 柽柳灌丛沙堆及丘间地蚀积分布随背景植被变化的风洞实验 |
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| 引用本文： | 谭凤翥,王雪芹,王海峰,徐俊荣,袁鑫鑫.柽柳灌丛沙堆及丘间地蚀积分布随背景植被变化的风洞实验[J].干旱区地理,2018,41(1):56-65. |
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| 作者姓名： | 谭凤翥 王雪芹 王海峰 徐俊荣 袁鑫鑫 |
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| 作者单位： | 1. 中国科学院新疆生态与地理研究所莫索湾沙漠研究站, 新疆 乌鲁木齐 830011;
2. 中国科学院大学, 北京 100049 |
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| 基金项目： | 国家自然科学基金项目“沙漠绿洲过渡带柽柳灌丛堆蚀积程及机理研究-以塔克拉玛干沙漠南缘为例”（编号41371042）资助 |
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| 摘 要： | 以塔克拉玛干沙漠南缘沙漠-绿洲过渡带广泛分布的柽柳灌丛沙堆及丘间地植物为原型，依据风沙运动相似理论，制作背景植被盖度依次为0%、4%、10%、16%和26%五组灌丛沙堆模型，在风洞中进行蚀积变化规律模拟实验。结果表明：柽柳灌丛沙堆及丘间地蚀积分布可划分为6个区域，依次为沙堆前积沙区、沙堆迎风坡风蚀区、沙堆两侧风蚀区、沙堆背风侧涡流积沙区、沙堆后尾流积沙区和不受沙堆影响区。随着指示风速增大，沙堆前积沙区和尾流积沙区范围缩小而沙堆两侧风蚀区面积明显增大。随着背景植被盖度的增大，沙堆前积沙区和尾流积沙区范围增大而沙堆两侧风蚀区范围明显减小。灌丛沙堆及丘间地整体风蚀面积比、风蚀率、各分区蚀积强度均呈指数规律递减。背景植被盖度为0%时，灌丛沙堆影响区风蚀率明显高于不受沙堆影响区，说明裸露地表条件下灌丛沙堆的存在会加剧地表风蚀；当背景植被盖度为4%~16%时，灌丛沙堆影响区风蚀率均低于不受沙堆影响区，可见丘间地植被存在可使灌丛沙堆起到一定的防风阻沙作用。当背景植被盖度>16%时，柽柳灌丛沙堆及丘间地整体蚀积强度和风蚀率变化趋于平稳。据此认为维持不低于16%的背景植被覆盖，是沙漠-绿洲过渡带柽柳灌丛沙堆科学保育的关键。
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| 关 键 词： | 柽柳灌丛沙堆 蚀积变化 背景植被盖度 风洞实验 |
| 收稿时间： | 2017-09-09 |
Wind tunnel simulation on distribution change of erosion and deposition around nebkhas and interdune under different background vegetation coverage |
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| TAN Feng-zhu,WANG Xue-qin,WANG Hai-feng,XU Jun-rong,YUAN Xin-xin.Wind tunnel simulation on distribution change of erosion and deposition around nebkhas and interdune under different background vegetation coverage[J].Arid Land Geography,2018,41(1):56-65. |
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| Authors: | TAN Feng-zhu WANG Xue-qin WANG Hai-feng XU Jun-rong YUAN Xin-xin |
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| Institution: | 1. Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China;
2. University of Chinese Academy of Sciences, Beijing 100049, China |
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| Abstract: | Based on the similarity theory of wind and sand movement,the study took the Tamarix nebkhas and interdune plants,which are widely distributed in Oasis-desert ecotone at the southern rim of the Taklimakan Desert,as the research prototype to create five sets of nebkhas model with background vegetation coverage of 0%,4%,10%,16%,26%,respectively to conduct the simulation experiment of erosion and accumulation change rule in the wind tunnel.The results show that:erosion and deposition distributions among Tamarix ramosissima nebkhas and interdune can be divided into six areas:depositional area in front of nebkhas, the eroded area on nebkhas' windward slope, the eroded area on nebkhas' both sides, the vortex depositional area on nebkhas' leeward side, the wake depositional area behind the nebkhas and the unaffected area. Along with the increase of the wind speed, range of frontal depositional area and wake depositional area shrinks while that of the eroded land on nebkhas' both sides decreases significantly. In addition, along with the increase of background vegetation cover range of frontal depositional area and wake depositional area increased while that of eroded land on nebkhas' both sides decreases significantly. The entirety erosion area ratio, the wind erosion rate and the erosion/accumulation intensity on the partitions are all decreasing with exponential law. When the background vegetation coverage equals to 0%, wind erosion rate in nebkhas-affected area is obviously higher than that non-nebkhas-affected area, which indicates that the presence of nebkhas will increase the wind erosion on bare surface. When the background vegetation coverage equals to 4%-16%, the wind erosion rate of the nebkhas-affected area was lower than that of the non-nebkhas-affected area, which means that the presence of interdune vegetation around nebkhas could, to a certain degree, make contribution to wind breaking and sand blocking. When the background vegetation cover is over 16%, change of the erosion intensity and wind erosion rate of Tamarix ramosissima nebkhas and interdune become level off. It is considered that keeping the background vegetation coverage not less than 16% is the key to the scientific conservation of theTamarix nebkhas in the Oasis-desert ecotone. |
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| Keywords: | Tamarix ramosissima nebkhas change of erosion and deposition background vegetation coverage wind tunnel simulation |
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