Sand Transport Rate Research Articles

A fully predictive model for aeolian sand transport, part 2: Description and calibration of models and effect of moisture and coarse materials

This paper presents new research results on the effect of moisture and coarse materials (gravel and shells) on aeolian transport and is a continuation of earlier work. Two mini wind tunnels have been designed and used to study the effect of moisture and coarse materials on the threshold shear velocity and on the sand transport rate at wind velocities in the range of 10–16 m/s. Extensive attention was given to the determination of the drying time of the beach surface after a period with rainfall for a range of temperatures and wind conditions. A new equation to include the effects of coarse materials on aeolian sand transport is derived from the mini wind tunnel data. Two prediction methods for aeolian sand transport were evaluated: the modified Bagnold-transport equation and the new VR-transport equation. Both methods include the effects of sand diameter and the threshold shear stress, which is essential for accurate determination of sand transport at low wind speeds. The cessation-related threshold shear velocity produces the best results. The grain-related shear velocity is the basic driving parameter of both prediction methods. The wind tunnel data of Belly (1964) have been used to calibrate the new VR-sand transport equation.

Determination of optimum vegetation type and layout for soil wind erosion control in desertified land in North China

Soil erosion due to aeolian processes is one of the most important forms of soil erosion and environmental quality problems in northern China. Vegetation cover in the process of wind erosion can protect the surface soil through a variety of ways to reduce wind erosion, which has long been recognized. However, in the quantitative study of the protective effect of vegetation cover, there are serious deficiencies for a long time. In this investigation, areas of bare flat desertified land utilizing different vegetation measures in the Zhangbei area of Zhangjiakou, China, was selected as the area which is being simulated in the wind tunnel. By using an experimental research method incorporating indoor wind tunnel simulation, the effectiveness and mechanism of vegetation restoration technical measures to prevent and control soil wind erosion are discussed. The main findings from this study are: (1)In the horizontal direction, soil wind erosion sand transport rates under a single vegetation type were in the order of: evergreen coniferous trees>deciduous broad-leaved trees>grasses>shrubs. When vegetation types were combined, soil wind erosion and sand transport rate under a combination of trees and shrubs was the largest, and a combination of trees and grasses measure was the smallest. (2) In the vertical direction, the rate of sand transmission under a single vegetation type was in line with the exponential function relationship with height change; whereas under combined vegetation measures, the soil sand transmission curve had a “C” shape. (3) Different methods of vegetation combination had different effects on the wind erosion rate, when the combination mode was mixed by rows or mixed by groups, minor differences were recorded in the wind erosion rate, and their wind erosion rates were less than those recorded under a mixed pattern between plants. Our results indicate that vegetation structure can be optimized on desertified land to weaken soil wind erosion in arid and semi-arid typical areas, thereby reducing soil dust emissions and protecting land productivity and the atmospheric environment.

Comparison of equilibrium sand transport rate model predictions with an extended dataset of field experiments at dry beaches with long fetch distance

New experiments on aeolian sand transport have been conducted on two Belgian beaches in the period between 2016 and 2018. Meteorological variables and aeolian sand transport rates were simultaneously measured on the subaerial beach. The field study aims to provide insight into the relationship between the transport rate of dry sand and shear velocity. Previous results from similar field studies were included to extend the dataset. Various aeolian sand transport models, predicting equilibrium transport rates for dry sand, were evaluated. The key parameter in all these aeolian models is the shear velocity (u*) derived from the measured velocity profiles. Mean shear velocities at the Belgian beaches were averaged over 10-minute periods and ranged from 0.2 to 0.7 m/s. Transport rates of dry sand ranged from 2 to 37 g/m/s. Zingg’s 1953 model produced the best results for the field data. Still, a large variability is found in the datapoints, advocating the need of high-quality field data on aeolian sediment transport.

Numerical analysis of the influence of the near ground turbulence on the wind-sand flow under the natural wind

The near-ground turbulent flow of nature air should have an important influence on the wind-sand flow, because of the vegetation and/or micro-topography. However, due to the complexity of turbulent flows, the effects of such turbulences and dust particles are still unknown. In this paper, the large eddy simulation–discrete element method was used to simulate the wind-sand flow. The results show that the response time of the wind-sand flow to turbulence is approximately 1.6 s. In addition, the response time increases rapidly as the particle size increases. The turbulence impact on the sand transport rate first increases and then decreases as the wind velocity fluctuation intensity increases. The sand transport rate is enhanced when the turbulence intensity is less than 0.25, whereas it is weakened when the turbulence intensity exceeds 0.25. Furthermore, the smaller the particle size, the more significant the effect. The effect of turbulence is mainly concentrated at 0.1–0.2 m from the ground and the turbulence increases the height of the wind-sand flow.

Gas-solid two-phase flow-driven triboelectric nanogenerator for wind-sand energy harvesting and self-powered monitoring sensor

A new type of gas-solid two-phase flow-based triboelectric nanogenerator (WS-TENG) is fabricated for collecting triboelectric energy in wind-blown sand environment, producing direct current output, and harvesting kinetic energy of continuous wind-blown sand flow. A single-electrode mode WS-TENG is designed with polytetrafluoroethylene (PTFE) as friction layer and used to investigate triboelectrification between wind-blown sand flow and friction layer surface using sediment-air injection method. Results showed that both short-circuit current (Isc) and output voltage (Vo) are direct current modes that increase with increasing impact angle and sand feed rate and reach 2 µA and 55 V, respectively, at a flow velocity of 18 m·s−1 to charge capacitor and light up five LEDs as a wind-blown sand flow kinetic energy collector. Moreover, output performance of WS-TENG can be improved further by pre-charging the floating sand using a PTFE pipe due to coupling of electrostatic induction and triboelectrification effect. WS-TENG was also applied as a self-powered sensor for aeolian sand transport rate in harsh sandstorm environment, thereby indicating its potential application for tracking the evolution of aeolian desertification and developing practical sensing applications of gas-solid two-phase flow-based TENG.

Recent Shoreline Changes Due to High-Angle Wave Instability along the East Coast of Lingayen Gulf in the Philippines

A small perturbation on the shoreline may develop under high-angle wave conditions, resulting in the formation of sand spits along the shoreline. Serizawa et al. explained the development of sand spits caused by the instability mechanism using the BG model (a model for predicting 3-D beach changes based on Bagnold’s concept). However, examples of the development of sand spits caused by this mechanism in the field are limited in number. Lingayen Gulf in the Philippines has a large aspect ratio, so shoreline instability occurs along the coastline, significantly affecting the shore protection along the coast. In this study, the shoreline instability along the river delta coasts around the Balili and Aringay Rivers flowing into Lingayen Gulf and a sand spit were investigated using satellite images together with field observation. The shoreline changes observed south of the Aringay River mouth were compared with those observed in a previous study on the development of a sand spit by San-nami et al. The rate of longshore sand transport to form a sand spit at Santo Tomas in Lingayen Gulf was estimated to be approximately 1.3 × 105 m3/yr, which is in good agreement with the value measured on the Shimizu coast in Suruga Bay, with a comparable aspect ratio of 1.2 relative to 1.3 in Lingayen Gulf. It was concluded that shoreline undulations have evolved downcoast of two river deltas owing to high-angle wave instability along the east coast of Lingayen Gulf and the formation of a sand spit has occurred. A soft measure, such as sand bypassing, would be better to be adopted along the coasts in Lingayen Gulf instead of hard measures against erosion, to prevent rapid expansion of an artificial, protected coastline.

Reducing aeolian sand transport and beach erosion by using armour layer of coarse materials

A man-made dune-beach-spit system at the south-east side of the island of Texel (Prins Hendrik site) has been built in 2018–2019 to strengthen the traditional dike. The core of the dune-beach-spit system consists of medium fine sand with a d50 of 0.25–0.3 mm. The beach is covered with an armour (protection) layer of coarse materials with relatively large gravel and shell fractions to reduce wind erosion and thus maintenance costs. In the design phase of the project the aeolian sand transport model of Bagnold was used to estimate the long-term erosion losses of sand at the new dune-beach system. This transport model was validated in the design phase by using detailed sand transport and bed roughness measurements at a nearby site called The Hors. This site is a wide natural beach plain of sand (d50 = 0.23 mm), where 147 high-quality datasets have been collected using a wind mast equipped with 5 cup anemometers and various sand traps. It is shown that the measured sand transport rates at the Hors can be reasonably well represented by the modified Bagnold-equation for dry sand. After completion of the new dune-beach system, a field experiment was performed at the Prins Hendrik site to verify the sediment transport predictions and erosion loss of sand. Data from two permanent wind masts and one short, mobile wind mast were used to derive the effective roughness of (stationary) bed forms. Sand transport rates were measured at various locations using a new trap sampler. The measured sediment transport in the armoured beach zone can be reasonably well represented by the Bagnold-equation using a multi-fraction approach with hiding-exposure coefficient. The predicted transport rates have been used to estimate the annual loss of sand from the Prins-Hendrik site.

Field observations of sand flux and dust emission above a gobi desert surface

Gobi deserts are a major source of natural and anthropogenic aerosols in China. However, the characteristics of the sand flow and dust emission processes are still an open question. This study intends to accurately describe the characteristics of the sand flow and dust emission and to determine the relationship between the sand transport rate and the vertical dust flux above a gobi surface. In this study, a field observation was conducted over a gobi (gravel) desert surface (Yangguan Gobi Desert, Gansu Province, China). We investigated the wind velocity, sand flux, and concentration of particles smaller than 10 μm (PM10) by using cup anemometers, a sonic anemometer, sand traps, and DustTrak. We found that (1) piecewise regression described the vertical sand flux profiles; the upper part of the profile (above 17 cm) should be described by a power function and the lower part should be described by a Gaussian function. (2) An empirical model based on the modified Owen equation could predict the sand transport rate accurately. (3) The vertical dust flux was described well by Fv∝u*3 and the dust emission above the gobi surface should follow Aρu*t (u*2 − u*t2), where A is an empirical regression coefficient. (4) The efficiency of saltation bombardment (Fv/Q) was linearly related to the ratio u*t/u*. The results of this study show that the characteristics of the sand flow and dust emission above a gobi surface were highly different from those of bare sandy surface. In future research, it will be necessary to account for the effect of surface characteristics, and particularly the characteristics of the gravel, to improve the predictive ability of our model.

A laser sheet sensor (LASS) for wind-blown sand flux measurement

There is a tendency to use high-frequency piezoelectric, acoustic, and optical sensors to measure aeolian sand transport rates in the aeolian community. However, most of these sensors are particle counters with inconsistent sensitivities or low saturation limits. Here we introduce a commercial laser sheet sensor (LASS) that can be deployed streamwisely to measure local saltation flux or perpendicularly to capture the bulky character of sand streams. Our laboratory and field experiment results show that LASS sensors respond linearly to the sand flux over the range of 0–20 kg m−2 s−1, covering most saltation events in nature. The LASSes are extremely consistent. They maintain their functionality even with minor lens contamination or laser misalignment during deployment. LASSes should not be deployed in environments with poorly sorted or moist sand or non-unidirectional wind.

A model of the sand transport rate that accounts for temporal evolution of the bed

Aeolian sediment transport is influenced by a variety of bed surface properties. During wind erosion, the dynamic changes of many bed surface properties lead to dynamic changes of the sand transport rate. However, researchers often simplify their research by ignoring these changes, in part because the wind velocity is stable in a wind tunnel. This leads to an incomplete understanding of aeolian sand transport processes. In the present study, we quantified how the sand transport rate changes with increasing averaging time in a wind tunnel. We found that the average sand transport rate decreased with increasing wind erosion averaging time. This phenomenon had two causes: First, because the sand bed surface became increasingly rough during erosion, the wind's sediment transport capacity decreased. Second, the bed surface became increasingly coarse-textured as fine particles were removed by the wind, thereby decreasing sediment availability at the surface. Based on these experimental results, we established a new sand transport model that accounts for the effect of averaging time on the sand transport rate. We demonstrate the performance of the model using additional wind tunnel data.

Evaluation of wind erosion control practices at a photovoltaic power station within a sandy area of northwest, China

AbstractThe widespread construction of photovoltaic power stations within northwest China poses an environmental threat because of severe increased wind erosion and land degradation. Engineering, plant, and biocrust treatments were evaluated in this study for their effectiveness in the reduction of wind erosion. The placement of solar panels caused wind speed variation and resulted in distinct abrasion and deposition zones between the rows of the solar panels and the formation of deflation zones under the solar panels. Combined treatments (gravel and red clay mulch were applied within the abrasion and deposition zones, respectively) and moss‐crust were the optimal choices within the engineering and biocrust treatments, respectively. We found that for engineering treatments, the combined procedures led to treatments had sand transport rate reductions of 87%, while the straw checkerboard, gravel, and red clay treatments gave reductions of 51, 78, and 74%, respectively. Within the biocrust treatments, the moss‐crust decreased the sand transport rates and the sand erosion–deposit budget by 71 and 114%, respectively, while the cyanobacteria crust caused reductions of 65 and 109%, respectively, in comparison to the control. Both plant treatments decreased the sand transport rates and the sand erosion–deposit budgets, but were inferior to other optimal treatments with the best plant treatment dependent on the placement pattern used for plant establishment. All the treatments had effects on reducing wind erosion, and we strongly recommend the use of moss‐crust and combined treatments in the deflation zones and between the rows of the solar panels, respectively, to significantly reduce the severe wind erosion occurring at these photovoltaic power stations located in sandy areas.

Morphological Profiles of Sand Dunes from ICESat-2 Geolocated Photons

Aeolian process leads to the transportation and accumulation of sand particles that result in sand dune landforms. The structure and shape of the sand dunes are driven by the parameters of interacting wind force and the material composition of sand within. Cross-section profiles over the sand dunes will essay the geomorphological parameters through which the steady state and rate of sand transport can be computed. National Aeronautics and Space Administration’s novel satellite namely Ice, Cloud and land Elevation Satellite-2 (ICESat-2) hosts a solo sensor namely Advanced Topographic Laser Altimeter System (ATLAS) which is a photon counting instrument that measures the round-trip time of the light pulse being emitted and reflected back from the surface determines the true height of the topographic feature on the Earth. In this article, cross-section profiles generated from the beams of ICESat-2 ground-tracks acquired over sand dunes of the Thar Desert region were analysed for detecting the geomorphological parameters. Observations from the cross-section profiles have resulted in giving unprecedented details about the shapes and morphological settings of various types of sand dunes like barchanoids, parabolic, longitudinal, and transverse dunes. Morphological parameters of sand dunes like the length of the stoss slope, crest height, slip face details, inter-arms spacing, height of the trailing arms, length of the depositional lobes, and sinuosity of the recurring crest lines were retrieved with ease from the Level-2A data product namely ATL03 of ICESat-2/ATLAS.

Aerodynamic and impact thresholds for cohesive mixture of sand and non-volatile liquid

The moisture has been recognized to have a significant influence on the initiation movement of sand by wind and consequently on sand transport rates. The pertinent literature regarding these phenomena is sparse and current available theoretical and empirical models exhibit considerable disagreement regarding the magnitude of moisture effects. We believe that these discrepancies comes from the fact that the moisture levels are not well controlled neither properly measured and are susceptible to strongly vary over time due to evaporation. To get rid of the variability of moisture content due to evaporation, we propose a new approach based on the use of non-volatile liquid, namely silicon oil instead of water. This insures a proper control of the liquid content and the production of reliable data concerning the variation of the transport threshold with liquid content.

An improved model to estimate annual sand transport rate by sand-driving winds

Some of the surface on Earth, Mars, Venus, and Titan is covered by ripples, dunes, and other features formed by sand-driving winds. Many developing countries in arid and semiarid areas are caught in a dilemma between the threat of sandy desertification and the development of wind energy. The estimation for the probability of sand-driving winds has been rarely studied. The ability of two-parameter Weibull probability distribution to estimate sand-driving winds is questioned. Sand transport rate is used only for the evaluation of short-term aeolian activities. Drift potential (DP) is an accessible way of evaluating potential sand transport volume by sand-driving winds. However, the relationship among annual sand transport volume, DP and wind energy has been rarely studied. Sand-driving winds can be divided into gentle winds and strong winds, but it is hard to distinguish them and to quantify their effects on aeolian geomorphology. A function was constructed from expressions of sand transport rate and the two-parameter Weibull probability distribution to improve the estimation of sand-driving winds. On this basis, annual sand transport volume was accurately evaluated by sand-driving winds. This is applicable to arid and semiarid areas worldwide. The relationship among annual sand transport volume, DP and wind energy was analyzed from the perspective of dimensional analysis. Gentle winds and strong winds are distinguished by transport wind velocity at which aeolian activities on a sandy underlying surface reach the erosion–deposition balance, and which corresponds to annual maximum sand transport rate. On a sandy underlying surface strong winds control deposition, while gentle winds dominate wind erosion. The transport wind velocity is nearly constant, weakly related to the probability distribution of sand-driving winds. These results provide a basis for an improved understanding of aeolian activities as an important planetary surface process, sand control engineering, and wind energy development.

The effects of different types of vegetation restoration on wind erosion prevention: a case study in Yanchi

Improving wind erosion prevention in the key ecological zones of sand fixation are closely linked to human welfare in China and Northern Eurasia. In this research, we studied the sand transport rate (STT), soil water content (SWC), and retention rate of the wind erosion prevention services (RR) in five experimental zones in Yanchi Country, including bare sandy land (BL), and four restoration zones with different types of vegetation restoration approaches, including artificial restored grassland with low-coverage (AGL), artificial restored grassland with high-coverage (AGH), artificial shrub land (AS), and naturally restored grassland (NG). The results showed that: (1) From 2006 to 2018, the STTs of the four restoration zones were lower than those of BL, and those of the AS were much lower than those of AGL, AGH, and NG; (2) in the rainy season, the SWCs of AS, NG, AGH, AGL, and BL were 3.01%, 2.80%, 2.79%, 2.68%, and 2.41% respectively. In the dry season, the SWCs of NG, BL, AGH, AHL, and AS were 2.86%, 2.93%, 3.00%, 3.08%, and 3.20%, respectively. The differences in the SWCs between the two seasons of BL were the largest (0.52%), while those of NG were the lowest (0.06%); (3) the annual average RRs in AS, AGH, NG, and AGL were 74.41%, 69.41%, 69.28%, and 61.64%, respectively, while the annual change of the RR in the NG was the smallest. This study reveals the effects of different types of vegetation restoration on wind erosion prevention in Yanchi country, thereby providing a scientific basis for policymakers to engage in effective vegetation restoration and formulate ecological protection policies.

Two-dimensional tide-induced residual sand transport: Applications to the Jiangsu coast, China

The residual sand (D > 62.5 μm) transport (RST) refers to the tidally averaged rate of horizontal sand transport. Albeit much smaller than the peak rates, it determines the morphological evolution. The analytical expression for the tide-induced RST has been reported in the condition of one-dimensional tidal currents by van de Kreeke and Robaczewska (1993). Here we extended the analytical solution to two-dimensional. The constituents of the residual, M2, and M4 tidal current velocities were used to characterize the collinear tidal current in the orthogonal X and Y directions, i.e., cross-shore and alongshore, respectively, while the M2 tidal constituent is dominant in both directions. Based on the solution, RST is controlled by a series of triple interactions of the M2 tidal velocity in the X direction, M2 tidal velocity in the Y direction, and the residual or M4 velocity in the X or Y direction. The solution was applied to the tide-dominated continental shelf of the Jiangsu coast, China, where the alongshore current is much stronger than the cross-shore component. The results show that the triple interactions of the cross-shore M2 tidal velocity (UM2), the alongshore M2 tidal velocity (VM2), and the alongshore residual velocity account for the major parts of both the alongshore and cross-shore RST in the nearshore area. The RST patterns promote sand accumulation in the shallow nearshore area and generate a narrow and active conduit of coastal alongshore sand transport. These findings can be applied in similar marine environments to understand the effects of non-linear tidal interactions in RST.

Using Historical Data to Examine the Accuracy of Sand Transport Field Measurements in Two Nearshore Marine Settings

Amos, C.L.; Kassem, H.; Townend, I.; Umgiesser, G.; Madricardo, F.; Zaggia, L.; Manfe, G.; Lorenzetti, G., and Gomez, E., 2020. Using historical data to examine the accuracy of sand transport field measurements in two nearshore marine settings. Journal of Coastal Research, 36(5), 1013–1028. Coconut Creek (Florida), ISSN 0749-0208.A re-analysis of historical data from two field campaigns was undertaken to examine the accuracy of measurements of bed load (Qb) and total transport (Qtot) of sand in (1) a wave-dominant shoreface off western Newfoundland, Canada, and (2) a tide-dominant inlet of Venice Lagoon, Italy. Video tapes recorded within Sea Carousel (a benthic annular flume) deployed off Newfoundland were used to determine the transport of medium to coarse sand under controlled unidirectional flow conditions. These results were compared with Helley-Smith sand trap measurements of bed load of fine to medium sand in a tidal inlet of Venice Lagoon, Italy. Ripple migration rates in Sea Carousel were similar to those measured in rivers and shallow marine settings at similar flows. Accuracy of sand transport rate (derived from ripple motion) was assessed by comparison to fundamental methods presented in the literature. Some of the scatter in correlations with earlier methods was removed by using a nondimensional form of total sand transport and correlating it to excess stream power (i.e. above a traction threshold). Better correlations were found between immersed (bed load) transport rate and excess stream power by applying a published adjustment to the observations for flow depth and grain diameter. Total immersed (normalized) sand transport () in Sea Carousel correlated with excess stream power in a fashion similar to results reported in the literature: = 0.288(ω – ωcr)1.65 kg m–1 s–1, where the immersed total sand transport is normalized with respect to flow depth and grain diameter. The sand trap data also followed this fit in part (2006 data only) but demonstrated greater scatter. The data herein thus fell in line with those reported in the literature from a wide variety of flume and field settings and for a wide variety of grain sizes. It is concluded that annular benthic flumes offer a reasonable and reliable method of assessing sand transport under controlled conditions of flow. The results from Sea Carousel and the Helley-Smith traps appear to follow the same relationships and so appear compatible. However, benthic sand traps show a higher degree of scatter, perhaps due to the uncertainties in how they sit on the seabed, and due to the arbitrary conditions of flow to which they are subjected when deployed.

Tidal current power effects on nearby sandbanks: a case study in the Race of Alderney.

A validated numerical model of tidal flows and sediment transport around the Alderney South Banks was used to investigate the potential effects of large (300 MW) tidal turbine arrays at different locations in Alderney territorial waters. Two methods were used, firstly looking at hydrodynamic changes only and secondly modelling sediment transport over a non-erodible bed. The baseline hydrodynamic model was validated relative to ADCP velocity data collected in the immediate vicinity of the sandbank. Real-world sand transport rates were inferred from sand-wave migrations and agree favourably with sediment transport residuals calculated from model outputs. Outputs from the sediment model reproduced realistic morphological behaviours over the bank. Seventeen different locations were considered; most did not result in significant hydrodynamic changes over the South Banks; however, three array locations were singled out as requiring extra caution if development were to occur. The results provide a case for optimizing the array locations for twin objectives of maximizing array power and minimizing impacts on the sandbanks. This article is part of the theme issue 'New insights on tidal dynamics and tidal energy harvesting in the Alderney Race'.

Abrasion of soil clods with different textures and moisture contents in sand flow environment

Abstract Abrasion is an important but complicated and fundamental process in soil wind erosion. To determine the relationship between the abrasion mass (AM) of soil clod and sand transport rate (q), and to investigate the influences of clod characteristics including moisture content, geometry, and soil texture on AM and on clod abrasion resistance, we conducted soil clod abrasion experiments in a wind tunnel. The soils types were aeolian sandy soil, loess soil, chestnut soil, and brown calcic soil, respectively. The abraders were the same soil as used for making the target clods. We found that moisture content obviously influenced AM, and the AM variation at relatively high friction velocity (u∗ = 0.44, 0.52, and 0.60 m∙s−1) showed different trends from those at lower u∗ (0.31 and 0.37 m∙s−1). For dry clods of each soil type, AM of the hexagonal prism clod was greater than that of cylindrical clod, but for moist clods, AM of the two geometries differed among soil types. We developed an AM prediction equation which mainly accounts for the mean particle size (d) and u∗. Using the abrasion coefficient (AC) as the abrasion resistance index, dry clods of the loess soil showed the strongest resistance, followed by clods of an aeolian sandy soil, chestnut soil, and brown calcic soil. However, AC could not quantitatively predict the resistance of moist clods.

The Influence of Surface Stress Fluctuation on Saltation Sand Transport Around Threshold

AbstractMultiscale wind velocity fluctuation and complex inertial response of sand saltation to wind variations give rise to intermittent and nonuniform sand transport, which greatly challenges the prediction of transport rate under wind conditions around saltation threshold. In this paper, three‐dimensional sand saltation within simulation domain of wind tunnel scale is modeled based on large eddy simulation of turbulent wind. Special attention is paid to the prediction of surface shear stress and consequently aerodynamic entrainment. When the wall stress model considering the influence of large‐scale turbulent structures was employed in case of relatively small resistance level for calculating particle aerodynamic entrainment, the model results predict sand transport below the impact threshold. The sand transport rate in this regime increases exponentially with mean wall stress, in contrast to the standard power law‐like behavior above the impact threshold. Aerodynamic entrainment and strong transport events lag behind high‐speed fluids sweep on a large scale even in wind tunnel, but the spatiotemporal variability of small‐scale sand transport is still unclear and quite complex due to transport inertia.