Study on the regulation of wind fields and soil particle size characteristics by newly designed box-shaped sand barriers

Field investigations reveal that under desert climatic conditions, the bases of conventional sand barriers frequently suffer severe erosion, reducing the contact area between the barrier and the sand bed and forming irregular concave surfaces within barrier cells; this can lead to tilting of barrier edges, changes in effective cell area, and ultimately a decline in protective function and service life. To address this issue, a novel “box-shaped sand barrier” is proposed, which utilizes sand accumulation to increase self-weight and improve ground contact, thereby enhancing resistance to wind erosion. Field experiments were conducted on barriers with different height configurations (front–rear equal height and front-low rear-high), and parameters including flow field structure, wind speed profiles, and wind acceleration rates were analyzed to evaluate their wind and sand control performance. Results show that, under the tested conditions, box-shaped sand barriers can influence near-surface wind-sand movement, forming five characteristic windbreak zones with distinct contour patterns; wind speeds decrease to 0.112–0.94 times those of untreated bare dunes (CK), while airflow acceleration rates increase with barrier height. In addition, the barriers can reduce wind-sand flow intensity and modify particle size distribution, with eroded materials mainly consisting of fine and medium sand and different barrier heights exhibiting distinct sorting effects. Overall, this study indicates the effectiveness of box-shaped sand barriers under the tested conditions in regulating wind-sand flow under field conditions and provides scientific support for improving barrier performance and informing the design of sand control and desertification management practices.