Bed microtopography around roughness element in the arid environment is often altered by airflow and sediment transport. Understanding the interaction among the roughness element, microtopography and airflow is important to reveal the mechanism of wind erosion around an isolated surface-mounted roughness element. The wind tunnel experiments studied the influence of cylindrical roughness element with larger aspect ratios on bed microtopography evolution, and the influence of microtopography on the wind flow around the isolated cylinder was analyzed by numerical simulation method. A deep well or scour surrounds the cylinder and a symmetrical V-shaped deposition area appears in the lee. Both the erosion and deposition areas of the wider cylinder with aspect ratio of 2 are larger than that of the taller cylinder (aspect ratio of 8). With the increase of blowing time, both the erosion and deposition areas around the wider cylinder increase, while for the taller cylinder, the sand deposition area increases first and then decreases, and the erosion area shows an increasing trend. After the local surface microtopography is adjusted, the streamwise wind velocity in the lee of the cylinder at half of cylinder height is less than the initial wind velocity on the unadjusted flat bed, while the wind speed near the ground in the lee is accelerated obviously. Moreover, the vortex in the recirculation zone behind the cylinder moves upward, leading to the increase of surface shear stress in the lee and surface erosion enhancement.

在干旱环境中，粗糙度元素周围的床层微观形貌通常会因气流和沉积物的输送而发生变化。了解粗糙度元素，微观形貌和气流之间的相互作用对于揭示孤立的表面安装粗糙度元素周围的风蚀机理很重要。风洞实验研究了长径比较大的圆柱粗糙度单元对床层微观形貌演变的影响，并通过数值模拟方法分析了微观形貌对孤立圆柱周围风流的影响。深孔或冲刷围绕圆柱体，并且在背风罩中出现对称的V形沉积区域。长宽比为2的较宽圆柱体的侵蚀和沉积面积均比高圆柱体（长宽比为8）大。随着吹气时间的增加，较宽圆柱体周围的冲蚀和沉积面积均增加，而较高的圆柱体中，砂的沉积面积先增大然后减小，并且侵蚀面积呈增加趋势。调整了局部表面微观形貌后，在缸身高度一半处的缸身背风中的流向风速小于未调节平板上的初始风速，而在身背地面附近的风速明显加快了。而且，在圆柱体后面的再循环区中的涡旋向上移动，导致在背风中表面剪切应力的增加和表面侵蚀的增强。沙粒沉积面积先增大后减小，侵蚀面积呈增加趋势。调整了局部表面微观形貌后，在缸身高度一半处的缸身背风中的流向风速小于未调节平板上的初始风速，而在身背地面附近的风速明显加快了。而且，在圆柱体后面的再循环区中的涡旋向上移动，导致在背风中表面剪切应力的增加和表面侵蚀的增强。沙粒沉积面积先增大后减小，侵蚀面积呈增加趋势。调整了局部表面微观形貌后，在缸身高度一半处的缸身背风中的流向风速小于未调节平板上的初始风速，而在身背地面附近的风速明显加快了。而且，在圆柱体后面的再循环区中的涡旋向上移动，导致在背风中表面剪切应力的增加和表面侵蚀的增强。lee地面附近的风速明显加快。而且，在圆柱体后面的再循环区中的涡旋向上移动，导致在背风中表面剪切应力的增加和表面侵蚀的增强。lee地面附近的风速明显加快。而且，在圆柱体后面的再循环区域中的涡旋向上移动，导致在背风中表面剪切应力的增加和表面侵蚀的增强。