干旱区地理2018，Vol.41Issue(1)：56-65,10.
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
Wind tunnel simulation on distribution change of erosion and deposition around nebkhas and interdune under different background vegetation coverage
摘要
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 the Tamarix nebkhas in the Oasis-desert ecotone.关键词
柽柳灌丛沙堆/蚀积变化/背景植被盖度/风洞实验Key words
Tamarix ramosissima nebkhas/change of erosion and deposition/background vegetation coverage/wind tunnel simulation分类
天文与地球科学引用本文复制引用
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):56-65,10.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 （编号41371042）
