在干旱区，戈壁砾石地表能够截留住风沙流中的沙尘，使得风蚀物发生沉降，从而保护土壤免受风蚀侵害。以往的戈壁风蚀研究主要集中在风蚀动力研究和风蚀影响因子研究，探究风蚀前后风蚀速率和风蚀因子的特征，但缺少对戈壁风蚀过程的研究，没能阐明输沙率和风蚀因子在风蚀过程中的变化。为研究戈壁地表风蚀特征，本文采用野外观测和风洞实验两种方案。选择甘肃省酒泉市阿克塞县戈壁地表作为研究对象，利用平口式集沙仪对观测场内不同风程长度的风沙流输沙率进行定量观测；同时，通过风洞实验，利用连续称重集沙仪对无外来沙源补给、不同粗砾覆盖条件下（0%、2.0%、2.9%、6.5%和23.2%）、不同风速条件下（11.96、13.95、15.95、17.96和19.95m/s）的模拟戈壁床面，实验研究了风蚀过程中床面输沙率和风蚀速率的动态变化规律。得出以下主要结论： （1）野外戈壁地表风沙流结构呈现出两种形式：在较低风速下（平均风速小于11m/s），输沙率随高度的增加而呈现指数型递减；在较高风速下（平均风速高于11m/s），输沙率随高度的增大而增加，在接近地表的某一高度上达到最大值，此后随高度的增加而减小，形成所谓“象鼻”结构。输沙率最大值出现的高度在4~8cm之间。戈壁风沙流结构特征值始终大于1，表明风沙流始终处于未饱和的搬运状态。戈壁风沙流结构受风程长度影响。 （2）戈壁地表输沙率受到风速、地表属性变化（可蚀性颗粒含量）和风程的共同影响。当风速增加时，戈壁地表输沙率随之增大。随着地表可蚀性物质的减少，戈壁表面输沙率呈现出减小的趋势。戈壁风沙流输沙率总体上随风程增加而增加，但在受到阵风或小型尘卷风干扰时，由于风速和风向的不稳定，在部分风程范围内出现输沙率随风程增加而减小的现象。野外戈壁地表风沙流达到稳定状态的临界风程长度在100m以上。 （3）风洞实验条件下，在风蚀的最初阶段（约0~5min内），戈壁床面输沙率和风蚀速率均随吹蚀时间的增加而迅速下降，此后趋于平缓，与风蚀时间呈现出幂函数关系。 （4）戈壁地表的粗砾能够有效抑制风蚀，从总体上看，随着粗砾覆盖度的增加，戈壁床面输沙率呈下降趋势。实验发现2.0%粗砾覆盖度对风蚀的抑制作用普遍较强，对戈壁床面的防护作用明显。根据风洞实验结果，建立了戈壁风蚀地表输沙率的过程经验模型，也相应建立了包含摩阻风速、粗砾覆盖度、风蚀过程持续时间等3个变量的风蚀过程经验模型。

In arid areas, the Gobi gravels can trap the sand and dust in the sand flow, causing the deposition of the eroded particles, thus protecting the soil from wind erosion. Previous studies on Gobi surface mainly focused on the study of wind erosion dynamics and influencing factors, and explored the characteristics of wind erosion rate and wind erosion factors before and after the wind erosion. However, the researches on the dynamic changes of sand transport rate and wind erosion factors in the erosion processes are still few. In order to study the dynamic characteristics of wind erosion over Gobi surface, field observation and wind tunnel experiment are adopted in this paper. The Gobi surface in Jiuquan city, Gansu province was selected as the studied object of our research. The sand transport rate with distance downwind was measured quantitatively by utilizing 6 flat mouth sand collectors. In wind tunnel experiments, continuous weighing sand collector was used to study the dynamic changing processes of the sand transport rate of each soil sample as erosion progressing, and the quantitative simulation study was carried out on the sand transport rate of gravel beds with different gravel coverages (0%, 2.0%, 2.9%, 6.5% and 23.2%), which is at various experimental wind speeds (11.96, 13.95, 15.95, 17.96 and 19.95m/s) and without sand feeding. The main conclusions are as follows: (1) The sand flow structure has two forms: At a low wind speed (the average wind speed is less than 11m/s), the sand transport rate decreases exponentially with height; At a higher wind speed (the average wind speed is higher than 11m/s), the sediment transport rate increases with height at the beginning, after reaching a peak value at a certain height over the gravel beds, decreasing with height, forming a so-called "elephant trunk" structure. The height where the maximum sediment transport rate occurred is about 4 to 8cm. The characteristic value of sand flow structure is always greater than 1, which means the Gobi sand flow is always in an unsaturated state. (2) Sediment transport rate of Gobi surface is affected by wind speed, surface properties (content of erodible particles) and the fetch length. When the wind speed increases, the sediment transport rate increases. With the decrease of erodible particles on the gravel beds, the sand transport rate shows a decreasing trend. On the whole, the sand transport rate over Gobi surface increases with the increase of the fetch length. However, when disturbed by gusts or small dust coils, due to the instability of wind speed and direction, the sand transport rate decreases as the wind speed increases sometimes. The critical length for sand flow reaching the stable state is over 100m. (3) Under wind tunnel conditions, in the first 5 minutes, the sand transport rate and wind erosion rate decreases rapidly with the increase of erosion time, and then tends to be stable, showing a power function relationship with time. (4) Coarse gravels on the surface of Gobi can effectively inhibit wind erosion. Generally speaking, with the increase of coarse gravel coverage, the sand transport rate on the Gobi bed shows a declining trend. It is found in the experiment that the inhibition effect of 2.0% coarse gravel coverage on wind erosion is generally strong, and the protection effect on Gobi bed is obvious. According to the results of wind tunnel experiments, an empirical model of sand transport rate in the processes of Gobi wind erosion was established, and an empirical model of the wind erosion processes, comprising friction wind speed, coarse gravel coverage and duration of the wind erosion processes, was also established.