If a soil is not protected by a closed vegetation cover - for example on arable land - strong winds can create turbulence at the earth's surface, soil particles can move and being transported. The long-term consequence is the loss of soil, accompanied by a reduction in soil fertility and thus a decrease in the yield capacity of agricultural soils.
Wind speeds of between 6 and 8 m per second (moderate to fresh wind; measured at a height of 10 meters above ground level) are already considered to trigger erosive soil loss by wind (BMEL 2001). Depending on the wind speed and the size of soil particles, they move in form of:
- Suspension (floating), which concerns smaller particles < 0.1 millimeter,
- Saltation (jumping), which concerns particles between 0.1 and 0.5 millimeters, or
- Reptation (rolling/creeping) for larger particles > 0.5 millimeters.
Jumping and rolling soil particles are often again deposited in short distances at wind barriers. In contrast, the fine, usually most fertile soil components (silt, clay minerals, humus and plant nutrients), can floatingly be transported over long distances. They get lost from the soil surface, while the coarser and humus-poor soil particles remain. This leads to a degradation of the soil structure and soil functions such as water and nutrient storage capacity decrease. This results in a reduction of soil fertility accompanied by a loss of biodiversity.
At the deposition sites, damage can be caused, for example, by plant cover and leaf abrasion (see figure). Nutrients and pollutants can increasingly adsorb to the fine particles, which can contribute to pollutant enrichment or eutrophication in neighboring sensitive terrestrial ecosystems or water bodies (see for example Critical Loads).
However, soil loss by wind erosion can also be dangerous to humans, for example when dust clouds form that lead to massive visibility obstructions (Wurbs and Steininger 2017).