Straw 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.

The transport and deposition of atmospheric particulate matter have attracted significant attention recently due to the increasing frequency of extreme disaster events, such as dust storms, volcanic eruptions, and extensive forest fires. The size distribution of the transported material and the conditions of the land–air interface are dominant factors in comprehending the detrimental potential of atmospheric particulate matter. However, it is still a challenge to understand the mechanism of dust deposition, especially over complex terrain. In an effort to investigate the deposition characteristics of particles over complex terrain, a series of experiments were conducted in a multifunctional environmental wind tunnel. The results show that the wind speed directly above the top of the mild slope model is significantly greater than that in the steep slope model, which indicates that a steep slope has a greater blocking effect on wind fields. At low wind speeds, the average wind speed at the top of the mild slope model is 17.8% higher than that at the top of the steep slope model, and at high wind speeds the average wind speed at the top of the mild slope model is 8.6% higher than that at the top of the steep slope model. The influence trend of the steep slope model and the combination model is basically the same, with both decreasing first and then increasing with the direction of wind velocity. The amount of surface deposition is greatly affected by the location of the feeding point and the microscale characteristics of the surface. In the steep slope model, the deposition is mainly distributed on the windward side, while the leeward side has a small amount of deposition. In the mild slope model, particles are deposited not only on the windward side, but also on the leeward side. The average rate of decline in deposition flux in the steep slope model is 88.4% and 75.1% in the mild slope model. The use of the combination model reduces the particle concentration at the back end compared with the single model. In three different models, the deposition on the windward side was shown to be significantly greater than that on the leeward side of the model. Our work increases understanding of the deposition of coarse dust particles over complex terrain and provides basic data for improving the accuracy of large-region particle transport and deposition simulations.

Coarse-particle deposition over steep terrain is shaped by the mismatch between rapid flow deflection and slower particle motion. We apply an existing Eulerian–Lagrangian numerical model to simulate the transport of 100 µm spherical alumina over a flat floor and a 0.20 m high triangular ridge at an incoming wind speed of 10 m s⁻¹. Wind-tunnel measurements are used to evaluate the simulated flow, particle motion, and surface deposition. For centerline deposition flux, root-mean-square errors normalized by the corresponding mean measured flux are 8.6% over the flat floor and 9.8% over the ridge. Transverse profiles show larger normalized errors of 20.1–40.8%. Over the flat floor, centerline deposition peaks about 3 m downstream of release. With the ridge present, floor deposition is enhanced on the approach and reduced at the sampled lee-side stations, followed by partial downstream recovery. Separate aperture measurements show greater collection at the sampled windward than leeward locations. The approach-region maximum overlaps the flat-floor landing zone; the measured approach-to-lee contrast provides clearer evidence of terrain-associated redistribution. Flow deflection, particle inertia, upstream removal, and wake exchange provide a physical interpretation of this sequence. The model captures the main streamwise redistribution under the tested conditions, although substantial discrepancies remain in some transverse deposition profiles.