Reassessing Soil Wind Erosion in Arid Regions of Central Asia: Fully Considering the Contribution of Non-Photosynthetic Vegetation (NPV)

Abstract

Wind erosion refers to wind transport of fine particulate matter and nutrient-rich materials. This form of erosion can have a considerable impact on the ecological environment and human health. Regional wind protection and sand fixation are considered to be major ecosystem services in arid zones. Previous applications of wind erosion assessment models in arid zones applied green vegetation as the main model parameter. However, there has been little consideration of the role of Non-Photosynthetic Vegetation (NPV) on wind erosion, which is widely distributed in arid zones. Therefore, this study reconstructed a soil wind erosion model (WEM) applicable to the arid zone of Central Asia by quantitatively assessing regional NPV and coupling NPV with the Revised Wind Erosion Equation (RWEQ) model based on the cusp mutation model. The results showed that NPV significantly reduced wind erosion in northern and central Kazakhstan from 2001 to 2020. The adequate consideration of NPV resulted in a reduction in simulated wind erosion in Central Asia by 400 t km⁻² per year. NPV had the greatest effect on wind erosion in spring and autumn, whereas it had least effect in winter, mainly due to the coverage of NPV and the seasonality of wind erosion. Regions showing a positive correlation between temperature and wind erosion were mainly located in northern Kazakhstan with a high coverage of NPV. Precipitation showed a negative correlation with wind erosion. Incorporation of NPV into the RWEQ model improved the accuracy of simulated wind erosion in Central Asia by 8.2%. The proposed method can support mitigation of wind erosion hazards and the improvement of the ecological environment in arid regions of Central Asia. This study can also act as a reference for improving the accuracy of large-scale simulation of wind erosion.