Influence of Wind Speed and Aggregate Size on Soil Loss from Heavy Metal-Contaminated Soils: A Wind Tunnel Study

Wind erosion is a fundamental process that facilitates soil degradation and redistribution of contaminants from polluted sites. Wind-tunnel experiments were conducted under controlled conditions to assess the effects of wind speed (8, 10, and 12 m s⁻¹) and aggregate size (0.5, 1.0, and 2.0 mm) on soil loss from heavy-metal-contaminated soils collected from a contaminated site in İncesu district of Kayseri, Türkiye. Experimental results indicated that aggregate size and wind speed had significant effects on soil loss (p ≤ 0.01). The greatest soil loss (30.85 kg m⁻²) was encountered in 0.5 mm aggregates at a wind speed of 12 m s⁻¹ and the lowest (5.15 kg m⁻²) in 2.0 mm aggregates at a wind speed of 8 m s⁻¹. Soil loss values decreased with increasing aggregate sizes, but increased with increasing wind velocities. Soil samples of different aggregate sizes were also subjected to heavy metal analyses. It was observed that finer aggregates had higher Zn, Cd, and Pb concentrations. Present findings revealed that aggregate size is a key parameter for wind erosion susceptibility of contaminated soils. It was also concluded that aggregate size could significantly affect redistribution of heavy metals through wind-driven soil loss. Management strategies and practices are recommended to promote aggregate formation and maintain surface stability of contaminated sites. Such practices are also recommended to reduce soil loss and contaminant dispersal in polluted sites.