Aeolian Sand Movement Research Articles

Aeolian sand cover on a granite peninsula (Hammeren, Bornholm, Baltic Sea) formed in three episodes during the past 11,600 years

Aeolian sand covers a significant part of the granite peninsula Hammeren on northernmost Bornholm in the Baltic Sea. The coastline of Hammeren is rocky and apart from one relative wide and sandy pocket beach at the east coast only few, small and gravelly pocket beaches exist. The aeolian deposits form three sand covers that stretch inland from the east and northwestern facing coasts of Hammeren. The largest sand cover forms a rising sand plain that cover the granitic landscape up to 700 m inland and reaches up to 60 m above sea level. Historical sources mention aeolian sand movement around CE 1775 in the middle of the Little Ice Age, but until this study no absolute age control has been available to confirm these observations. Luminescence dating of selected sample sites indicates that aeolian sand movement took place in three episodes. The first episode was in the last part of the Younger Dryas at about 11,500 BP, the second episode was in the Danish Late Bronze Age at about 2700 BP, and the youngest episode was indeed during the Little Ice Age around 200 BP (CE 1750). These episodes with aeolian activity all fall during relatively cold climatic intervals and add support to previous studies indicating a link between cold climates an increased storminess in Northwest Europe including the southern Baltic Sea region.

Aeolian saltation over plateau gobi: Field studies in the Zhongzaohuo gobi area, northeastern Tibetan plateau, China

Aeolian sand movement, affected by low air density, exhibits special characteristics. Our understanding of saltation, especially in plateau gobi regions, is limited. Here, we report results of aeolian saltation processes over gobi in the Zhongzaohuo area of the northeastern Tibetan Plateau using high-frequency saltation measurement. The key findings include: (1) In turbulent winds, aeolian sand saltation on plateau gobi occurs intermittently. As the aeolian sand transport activity parameter increases, the threshold wind speed Ut for sand movement decreases exponentially. Concurrently, the threshold wind speed required to move sand particles shows a significant increase, being 49%–68% higher than that in lower altitude gobi regions. (2) The average saltation height zq in plateau gobi ranges from 0.25 to 0.40 m, with a mean value of 0.36 ± 0.04 m, which is approximately 2.3–2.6 times higher than that in lower altitude gobi areas. (3) Sand transport rate in the plateau gobi is significantly reduced, being 57%–94% lower than that in lower altitude gobi areas. This research will deepen our knowledge of how turbulent winds affect aeolian sand movements in plateau gobi regions.

Wind Tunnel Test of Sand Particle Size Distribution along Height in Blown Sand

In aeolian sand movement, the vertical distribution of sand particle size is intricately linked to sand flux, wind–sand flow field and dune development. In the present study, the distribution characteristics of sand grains in four particle size ranges at nine heights were investigated through sand blowing tests at five different reference wind speeds. The correlation between sand particle size and wind speed indicates that when the particle size was ≥0.35 mm, there was a linear variation of mass percentage with wind speed. When the particle size was <0.35 mm, when Z ≤ 0.15 m, a linear variation of mass percentage with wind speed was found; when Z > 0.15 m, an exponential modification in mass percentage with wind velocity was observed for sand grains falling within this specific range of particle sizes. The correlation between sand particle size and height indicates that when the reference wind speed was ≥15 m/s, the mass percentage of sand particles varied linearly with height. When the reference wind speed was ≤13.5 m/s, the mass percentage of sand grains with particle size in the 0.25–0.35 mm range increases first and then decreases with increasing height. The present results can provide a reference for subsequent research on the aerodynamic characteristics of wind–sand flow fields and on the mechanism of dune formation.

Grain size ratio may be crucial for the fluid initiation of martian sand grains

The active Aeolian sand movement on the Martian surface has been puzzling scientists for several decades because the existing theories do not support the initiation of sand grains under the current Martian environment. In this study, I theoretically calculated the fluid threshold (u⁎ft) for the initiation of sand grain movement by considering the gravitational force, the drag force, the lift force, and the cohesive force. For a fixed grain diameter, u⁎ft calculated by considering the wind turbulence is generally less than the values obtained from well-known initiation threshold expressions. It also reveals that wind turbulence has a significant impact on u⁎ft of grains with diameters of greater than 50 μm on Earth and for those with diameters of greater than 500 μm on Mars. The grain size ratio (the ratio of a grain diameter on the bed surface versus the averaged diameter of a mixed sand bed) is a key parameter in determining u⁎ft of mixed sand beds. On Mars, the lowest u⁎ft, which occurs for mixed sand beds with average grain diameters of 50–150 μm, could be 0.6–0.7 m/s when the optimal grain size ratio is determined from the given grain size ratio range. Thus, the results of this study not only quantitatively agree with recent findings from wind tunnel experiments but also provide a theoretical explanation for the observations of active sand movement on Mars.

Experimental study on the effect of plant spacing, number of rows and arrangement on the airflow field of forest belt in a wind tunnel

Forest belts play an important role in soil wind erosion control and the prevention of aeolian sand movement in arid and semiarid regions. In order to reveal the effect of plant spacing, number of rows, and arrangement on airflow of forest belt, the airflow fields were measured in a wind tunnel for artificial single-row forest belts with different plant spacings, forest belts with different numbers of rows with the same plant spacing, and two rows of forest belts with different arrangements. The results indicate that for the single-row forest belt, the downwind airflow decreases in the canopy area and then recovers exponentially. As the plant spacing increases, the characteristic length of the downwind airflow recovery of the forest belt and the distance at which the minimum wind speed is located both decrease approximately exponentially. As the number of rows in a forest belt increases, the downwind airflow speed in the canopy area decreases. The average reduction of downwind relative wind speed decreases with plant spacing and increases with the number of rows. A forest belt with staggered arrangement has lower downwind speeds and a longer characteristic length of airflow recovery than that in rectangular arrangements.

Large-eddy simulation of sand transport under unsteady wind

Aeolian sand movement contributes to evolution of surface landforms on Earth and Mars, as well as on Venus and Titan. Most natural landforms in arid regions are molded by wind with a general feature of unsteadiness. Many researches have improved our cognition of saltation in unsteady flow, but it is probably true that this issue is not yet fully analysed. In this paper, we conducted three-dimensional numerical simulations of wind-blown sand under unsteady wind conditions. The trajectories of sand particles are simulated by using a Lagrangian model. Particle motion, particle-bed interaction and wind modification have been taken into account. Results indicate that the characteristics of sand transport in unsteady and steady wind conditions profoundly differ; the sediment transport in unsteady conditions is significantly enhanced and increases with the amplitude of the sinusoidal wind fluctuations; the time series of sediment transport reveals a sine-like variation which lags behind the variation of the wind with a time delay of about 1 s (response time of saltation to wind variation). In unsteady conditions, sand transport shows an ‘overshoot’ which is embodied in the initial wave of the sediment transport. The impact of unsteady sediment transport should be paid more attention in future Aeolian research.

Characteristics of Turbulent Aeolian Sand Movement Over Straw Checkerboard Barriers and Formation Mechanisms of Their Internal Erosion Form

AbstractStraw checkerboard barrier (SCB) array is one of the most effective and widely used measures for antidesertification projects. The efficiency and durability of SCB are greatly influenced by the features of wind field and sand particle motion. Unfortunately, very few studies have explored the characteristics of turbulent flow and the internal erosional form inside the barrier cell, because of the complexity of turbulent flow and the sand particle motion around the surface of SCBs. In this paper, we simulated the wind‐sand flow around SCBs using 3‐D hybrid Reynolds‐averaged Navier‐Stokes/large eddy simulation method and Lagrangian particle tracing method to analyze the characteristics of turbulent flow, particle motion, and internal erosional form of SCBs. The results show that the vast majority of particles fall into SCB cells from their middle and posterior parts when wind‐sand flow passes SCBs, due to the impact of gravity and subsidence flow. It indicates that SCBs could effectively prevent sand flow‐induced hazards. The turbulent flow in SCBs has great instantaneous pulse velocity, resulting in retransfer of sand particles in SCBs. Analysis of the mean flow field in SCB found one huge streamwise vortex that filled the SCB cells and two spanwise vortexes in the back of SCB cells. These vortexes will drive particles inside SCBs to move toward the front and side walls, making the erosional form of SCB cells low in the middle and high near all the sides.

Stability mechanisms of barchan dunes: A case study of Hexi Desert area in Gansu Province

Barchan dunes, an important type of dunes, are distributed on the edge of oases. Research of stability mechanisms of barchan dunes is of great importance to the determination of regulation of aeolian sand movement on the edge of oases. However, the stability of barchan dunes remains an unresolved scientific issue. In this paper, the stability mechanisms of the top of barchan dunes in Hexi desert area of Gansu Province were analyzed. The results showed that: (1) in Hexi desert area of Gansu Province, patches of barchan dunes were distributed downwind on the edge of desert. The distribution areas were flat sandy-clay or sandy-gravel beaches. The lowlands among the dunes were wide and had the prominent prevailing wind. (2) The prevailing northwestern wind caused the highest point and sand ridge line of the dunes to coincide, and the dunes to move forward and become lower. The southeastern wind (opposite to the prevailing wind) caused the highest point and sand ridge line of the dunes to separate, the leeward slope to be eroded by wind and the dunes to rise. (3) The higher the barchan dunes were, the longer the two flanks were, and the smaller the angle was. (4) The wide flat beaches were vital to the formation of barchan dunes and a chain of barchan dunes. The largely prevailing wind was the key factor for the stability of barchan dunes and a chain of barchan dunes. The opposite wind and the corridor effect of the two flanks were key factors for the increase of barchan dunes in size and height. The speed and distribution frequency of the prevailing and opposite winds were factors restraining the height of barchan dunes and a chain of barchan dunes here.

A numerical investigation into sand grain/slope bed collision

The impact of sand grain on sandy bed surface is not only one of the main processes of near-surface aeolian sand movement, but also the main cause of sand surface damage and soil erosion. In this study, we first simulate the process of grain-bed impact and splash of sand grains with different sizes on sand bed surface using the discrete element method. Then we analyze the relationships among the number, speed and angle of splashing grains and the speed and angle of the impacting sand grain with different slopes. Finally, we present the splash function of the takeoff speed and angle of splashing grains with the incident speed and angle changing and give their probability density distributions. This research is of great importance to understand the windblown sand movement on sand dune or ripples.

Analysis of an optical gate device for measuring aeolian sand movement

Abstract Movement of sand in response to wind is the most important feature of aeolian sediment transport on Earth and other planets. Through sand blasting during saltation, large amounts of dust are ejected into the atmosphere and transported long distances, impacting climate and human health. Despite continuing improvements, currently available devices for field measurement of sand movement have limitations. An optical gate device (OGD) for detecting the movement, size, and possibly speed of individual sand grains during aeolian sediment transport was analyzed. The approach uses the highly time resolved signal from these sensors, which consist of a light emitter and a photosensitive sensor. A specific OGD that is manufactured by Optek (Carrollton, Texas, USA) was tested in a sediment transport wind tunnel alongside trap-style devices. The OGD device provided particle counts and total signal response that were well correlated with sand trap data (R2 between 0.66 and 0.88). Inter-comparison among eight identical units of the OGD showed excellent repeatability (R2 > 0.98 for 7 of 8 units). Subsequent tests revealed that the response of the phototransistor (light sensor) can be linear when operated within certain workable limits. Practical implications of this are that there is potential for extracting size distribution information. Limits imposed by noise levels in the signal and interferences from extraneous light sources were also identified. Despite the results presented being specific to the OGD model tested, much of the approach outlined is applicable to any OGD-type device (including Wenglor®) if the signal of the photo detector can be accessed directly.

Environmental changes during the late Pleistocene and the Holocene in the Gonghe Basin, north-eastern Tibetan Plateau

Different types of aeolian sediments are widespread in Gonghe Basin on the north-eastern Tibetan Plateau. Despite that individual sections are often discontinuous, the analysis of a large number of individual sections distributed in the entire basin provides a valuable archive for the reconstruction of environmental changes since the late Pleistocene. This study presents 43 new OSL (optical stimulated luminescence) ages and combines them with 39 previously published ages from the Gonghe Basin for the last 16ka. From around 15 to 14ka onwards an increase in moisture facilitated the formation of a vegetation cover and the fixation of loess sediments on the northern and southern side of the basin. After enhanced mobility of aeolian sediments during the dry Younger Dryas greater than before precipitation fixated also the sands in the lower parts of the basin. The increase in moisture can be attributed to the strengthening of the Asian summer monsoon. A comparison with the timing of aeolian sediment accumulation in the neighbouring basins probably indicates a time-transgressive strengthening of the monsoon on the north-eastern Tibetan Plateau. Aeolian sands were first permanently stored from around 17ka at the Qinghai Lake in the north-east of the area and at 10.5ka at the Donggi Cona in the south-west. The Gonghe Basin is located in an intermediate position. Highest moisture values occurred during the mid-Holocene from around 7.5 until probably 2.5ka in the Gonghe Basin. In most parts of the basin aeolian activity was low during this time. In the central part of the basin aeolian sand movement occurred sporadically. Since 2.5ka aeolian activity in most parts of the basin resumed due to the late Holocene weakening of the Asian summer monsoon. However, the parallel accumulation of aeolian sands and silts indicates an increased human influence.

Episodes of aeolian sand movement on a large spit system (Skagen Odde, Denmark) and North Atlantic storminess during the Little Ice Age

Late Holocene coastal dune successions in north-western Europe contain evidence of episodic aeolian sand movement in the recent past. If previous periods of increased sand movement can be dated sufficiently precisely and placed in a correct cultural and geomorphological context, they may add to our understanding of storminess variation and climate change in the North Atlantic during the later part of the Holocene.

Pleistocene wind system in eastern Austria and its impact on landscape evolution

During cold periods in the Quaternary, the intracontinental Pannonian Basin was part of the European periglacial zone, and aeolian erosion had a profound effect in shaping the landscape. Geomorphologically most effective winds were channelled between the Alps and Carpathians and entered the Pannonian Basin from the NW. To assess the nature of meteorological conditions producing these winds, field studies were carried out in the foreland of the basin entrance, in eastern Austria.As a result, we report on the first bedrock ventifacts from Austria and aeolian sand occurrence in the Bohemian Massif. Through a compilation of published data and field work, the distribution of ventifacts was mapped and appears to be controlled primarily by available lithologies. Palaeo-wind directions were identified using mesoforms of bedrock ventifacts, especially flutes. The acquired air flow directions are accordant with the orientation of erosional landforms on soft sediments and form a coherent system, with westerly to north-westerly winds in the west, which turn towards the entrance of the Pannonian Basin in the east. There are no directions referring to the direct influence of katabatic winds produced on the ice sheet, instead, the wind system must have been driven by synoptic-scale patterns like the polar front. The narrow distribution of wind directions suggests that the low-altitude air flow system was relatively stable even without a funnelling topography as in the Pannonian Basin, though the Alps could have acted to deflect the winds. OSL data from the Bohemian Massif indicate aeolian sand movement during the Late Pleistocene. The results provide data for aeolian transport studies, among them for loess provenance analyses and can be used as input for climate models.

Air density effects on aeolian sand movement: Implications for sediment transport and sand control in regions with extreme altitudes or temperatures

AbstractAeolian sand transport results from interactions between the ground surface and airflow. Previous research has focused on the effects on sand entrainment and mass transport of surface features and wind velocity, but the influence of air density, which strongly constrains airflow characteristics and the resulting sand flow, has not been widely considered. In the present study, entrainment, saltation characteristics and transport rates were examined at nine experimental sites ranging in elevation from −154 m below sea‐level (Aiding Lake) to 5076 m above sea‐level (Tanggula Mountain pass on the Qinghai–Tibetan plateau). At each site, a portable wind tunnel and high‐speed camera system were set up, and the friction wind velocity, threshold friction velocity and sand flow structure were observed systematically. For a given volumetric airflow, lower air density increases the wind velocity. Low air density also creates a high threshold friction velocity. The Bagnold wind erosion threshold model remains valid, but the value of empirical parameter A decreased with decreasing air density and ranged from 0·10 to 0·07, the smallest values reported in the literature. For a given wind velocity, increased altitude reduced total sand transport and creeping, but the saltation rate and saltation height increased. The present results provide insights into the fundamental mechanisms of the initiation and transport of sand by wind in regions with an extreme temperature or altitude (for example, alpine deserts and low‐lying lake basins) or on other planets, including Mars. These results also provide theoretical support for improved sand‐control engineering measures. The data and empirical equations provided in this paper improve the ability to estimate threshold and transport conditions for wind‐blown sand.

Age and palaeoenvironmental significance of an inter-tidal peat bed at Ballywoolen, Bann estuary, Co. Londonderry

A recently exposed inter-tidal peat bed at Ballywoolen, Bann estuary, Co. Londonderry, has yielded new information about mid-Holocene coastal environmental change in the north-east of Ireland. Pollen analytical data and wood detritus demonstrate that peat accumulation occurred in a terrestrial environment that was free from marine influence. Radiocarbon dates suggest that the peat accumulated rapidly during a period of low relative sea level subsequent to the maximum of Holocene relative sea-level rise along the north coast of Northern Ireland. The absence of marine/brackish indicator taxa at the site suggests that the tidal range was somewhat less than that at present and/or that the channel of the river was located some distance east of its present alignment. The dates indicate that the low stand lasted for at least ~0.2 ka and possibly for ~1.1 ka. Stable, woodland-dominated landscapes are indicated at both this site and neighbouring ones around ~6.4-5.3 cal ka BP. There is no evidence for large-scale aeolian sand movement or human impact on the landscape during the period of peat accumulation.

Impact of atmospheric circulation patterns on coastal dune dynamics, NW Spain

Dunes in temperate latitudes have experienced a significant stabilization in recent times, essentially as a consequence of the expansion of dense vegetation cover. Yet, the causes for this gradual stabilization as well as the causes promoting antecedent aeolian mobilization remain poorly understood. The Traba coastal dune field, located in NW Spain, was examined to explore the causes inducing aeolian activity and subsequent stabilization since 1940. Morphological changes were identified through the combination of aerial photographs and geophysical techniques. Local wind field regimes were simulated using a regional climate model to obtain the variability of the most relevant modes of atmospheric circulation in the North Atlantic and European regions; North Atlantic Oscillation (NAO), Eastern Atlantic (EA) and Scandinavian (SCAND). This allows us to identify the impact of these circulation modes over dune dynamics. Results document an episode of aeolian activity during the 1950s followed by a gradual stabilization and fixation of the dune coincident with a decrease on storm and wind intensity. Yet, aeolian sand movement remained active in small areas (blowouts), occurring mainly during the summer. NE winds associated with a negative phase of the EA explain the movement of sand within the dune field under favorable conditions of sand supply. On the other hand, sand supply to the dune field from the beach was promoted by NW winds coincident with the summer negative phase of NAO. During winter, the negative NAO favored frequent SW winds associated with the passage of intense storms, which in turn explain sand remobilization from the beach making sediment available for the NW winds to blow inland. With this work, it is proven that to understand past and future aeolian activity requires critical consideration of the variability and impact of the two principal modes of atmospheric circulation in the North Atlantic (NAO and EA). The SCAND mode explaining a lower percentage of the local wind field variability was also included to achieve higher significance levels of explained variance.

雅鲁藏布江山南宽谷风沙化土地土壤养分和粒度特征

在雅鲁藏布江山南宽谷区,选择流动沙地、平缓沙砾地、半固定沙地、固定沙地和覆沙河滩地等类型样地,研究了不同深度(0-10 cm、10-20 cm和20-40 cm)土壤层的养分状况和粒度特征,探讨了风沙运动对土壤粒度组成和养分含量的影响。结果表明: 1) 风沙化土地土壤pH值呈中性、碱性和强碱性,土壤有机质和全氮含量均很低,但全磷和全钾均很高。土壤粒度组成表现为砂粒含量(53.83%-95.93%)> 粉粒(3.3%-40.5%)> 粘粒(0.77%-5.68%)。2) 粘粒和粉粒含量均以覆沙河滩地(分别为4.02%和27.95%)最大、半固定沙地(分别为1.35%和5.27%)最小。粘粒含量表现为覆沙河滩地> 固定沙地(2.98%)> 河滩流动沙地(2.89%)> 平缓沙砾地(1.69%)> 河岸流动沙地(1.54%)> 山坡流动沙地(1.49%)> 半固定沙地。不同类型沙地粉粒含量的大小顺序与粘粒含量相似,仅在山坡流动沙地和河岸流动沙地的大小顺序有所差别。砂粒含量以半固定沙地(为93.40%)最大、覆沙河滩地最小(68.05%)。不同类型沙地的砂粒含量与粉粒含量的大小顺序正好相反。3) 土壤养分含量与粘粒、粉粒、极细砂粒和细砂粒等细沙物质的相关性较强,与中砂粒、粗砂粒和极粗砂粒等粗沙物质呈负相关或相关性较弱。其中,粘粒和极细砂粒含量的增加对土壤养分的增加贡献较大。流动沙丘随风沙运动而不断往复摆动的现象和土壤细颗粒的迁移和损失,对不同类型沙地和沙丘部位的土壤养分状况及其再分配过程产生较大影响。;We conducted a case study to examine the soil nutrients content and grain size fraction of different aeolian sandy land types in the Shannan wide valley area, middle reaches of the Yarlung Zangbo River by choosing moving sandy land, flat sandy gravel land, semi-fixed sandy land, fixed sandy land and sandy land on flood plain as sample plots. The mechanism how aeolian sand movement affects soil grain size fraction and nutrients content of aeolian sandy land was discussed based on field sand movement observation and wind velocity and direction data from 1980 to 2006 from the Lhasa Airport meteorological station. The results showed that 1) The soil pH value of aeolian sandy land in the study area was neutral, alkaline or strong alkaline, and soil organic matter (SOM) and total nitrogen (TN) content were rather low, whereas total phosphorus (TP) and total potassium (TK) were very high. The soil grain size fraction followed the order of sand content (53.83%-95.93%)> silt content (3.3%-40.5%)> clay content (0.77%-5.68%), and the clay and silt content both presented rather low. 2) The clay and silt content was highest in sandy land on flood plain (4.02% and 27.95%, respectively), whereas that was lowest in semi-fixed sandy land (1.35% and 5.27%, respectively). The clay content in different aeolian sandy land types followed the order of sandy land on flood plain> fixed sandy land (2.98%) > moving sandy land on flood plain (2.89%)> flat sandy gravel land (1.69%)> moving sandy land on river bank (1.54%) > moving sandy land on hill-slope (1.49%) > semi-fixed sandy land. The order of silt content in different aeolian sandy land types was similar with that of clay content except for moving sandy land on river bank and moving sandy land on hill-slope. The sand content was highest in semi-fixed sandy land (93.40%), whereas it was lowest in sandy land on flood plain (68.05%), and the order of sand content in different aeolian sandy land types was just in contrast to that of silt content. 3) The correlation between different soil nutrients and the content of clay, silt, very fine sand, fine sand was strong, whereas the correlation was negative or weak between different soil nutrients and the content of medium sand, coarse sand, very coarse sand. The clay and fine sand content made larger contribution to the soil nutrients content. The aeolian sand movement, which caused the continuous swing of moving sand dunes and the migration and loss of the finer sand particles, affected the soil nutrients content and their redistribution process for different aeolian sandy land types greatly. The purpose of this study is to characterize the soil nutrients content and grain size fraction of different aeolian sandy land types, and to provide a scientific basis for the ongoing vegetation restoration that is being carried out for aeolian sandy land control.

Real-Time Simulation of Aeolian Sand Movement and Sand Ripple Evolution: A Method Based on the Physics of Blown Sand

Simulation and visualization of aeolian sand movement and sand ripple evolution are a challenging subject. In this paper, we propose a physically based modeling and simulating method that can be used to synthesize sandy terrain in various patterns. Our method is based on the mechanical behavior of individual sand grains, which are widely studied in the physics of blown sand. We accounted significant mechanisms of sand transportation into the sand model, such as saltation, successive saltation and collapsing, while simplified the vegetation model and wind field model to make the simulation feasible and affordable. We implemented the proposed method on the programming graphics processing unit (GPU) to get real-time simulation and rendering. Finally, we proved that our method can reflect many characteristics of sand ripple evolution through several demonstrations. We also gave several synthesized desert scenes made from the simulated height field to display its significance on application.

Statistical particle stress in aeolian sand movement-derivation and validation

The statistical particle stress (SPS) is a result of group particle movement, which is not referred directly from E–L (Euler–Lagrange) calculations. This paper derives SPS in Eulerian regime and proves that in aeolian sand movement, as the height increases the gas stress also increases while the SPS decreases; however, the sum of gas stress and SPS keeps to be a constant value, which equals to the gas stress in particle absent region. This paper also suggests that SPS predominates in the momentum transportation of particle phase.

CFD-DEM simulation of three-dimensional aeolian sand movement

A three-dimensional CFD-DEM model is proposed to investigate the aeolian sand movement. The results show that the mean particle horizontal velocity can be expressed by a power function of heights. The probability distribution of the impact and lift-off velocities of particles can be described by a log-normal function, and that of the impact and lift-off angles can be expressed by an exponential function. The probability distribution of particle horizontal velocity at different heights can be described as a lognormal function, while the probability distribution of longitudinal and vertical velocity can be described as a normal function. The comparison with previous two-dimensional calculations shows that the variations of mean particle horizontal velocity along the heights in two-dimensional and three-dimensional models are similar. However, the mean particle density of the two-dimensional model is larger than that in reality, which will result in the overestimation of sand transportation rate in the two-dimensional calculation. The study also shows that the predicted probability distributions of particle velocities are in good agreement with the experimental results.