泥漠风沙流结构是泥漠微观风沙运动的宏观表征，开展泥漠地表风沙流结构研究，对理解泥漠风沙运动过程，进而探究泥漠粉尘释放动力机制具有重要意义。本文选取额济纳旗北山周边典型洪积扇泥漠，对其近地表风沙流结构进行观测研究。结果表明：泥漠风速廓线曲线呈指数型，空气动力学粗糙度z₀为0.058 mm，小于沙漠和戈壁地表。泥漠输沙通量随高度变化呈指数递减规律，泥漠过境风沙流中沙粒平均跃移高度z_q为15 cm，90%输沙量集中于0~34 cm高度。其中，细沙粒径组输沙通量垂直剖面曲线与全样沙粒类似，而随着粒径的增大，泥漠输沙通量随高度发生变化，由类“象鼻”曲线过渡为粗沙的“斜Z型”曲线。基于以上研究结果，本文最终提出了泥漠床面沙粒运动的模式。

The structure of near-surface wind-blown sand flow over dry playa represents the macroscopic characteristics of micro-wind-blown sand movement at such locations. It is important to study such sand flow in order to understand the processes of wind-blown sand movement and dust emissions in dry playa. In this study, a dry playa at the end of a typical alluvial fan around North Mountain of the Ejin Banner was selected for analysis and field observations were conducted on its near-surface wind-blown sand flow structure. The results revealed an exponential wind speed profile over the dry playa surface and the aerodynamic roughness z₀ was 0.058 mm, which is smaller than those of sand and gobi surfaces. The sand flux of mixed-particle-size sand decreased exponentially with height over the dry playa surface. The average saltation height z_q of sand particles in the desert-crossing wind-sand flow was 15 cm, and 90% of the transport sand was concentrated within the height of 0-34 cm. The vertical profile curve of the sand flux in the fine-sand-particle-size group was similar to that of the mixed-particle-size sand. With increasing particle size, the sand flux in the dry playa changed with height, and the “elephant nose” curve transitioned to an “oblique Z” curve for coarse sand. Thus, this work proposes the mode of sand movement on the dry playa bed.