Spatial distribution of water and wind erosion and their influence on the soil quality at the agropastoral ecotone of North China

Abstract

Abstract: In semiarid regions, wind and water erosion are serious environmental and ecological problems around world. They have different impacts on soil quality over a range of spatial scales. Analyzing the spatial distribution of soil erosion and understanding the impacts of wind and water erosion on soil quality at the regional scale is vital for mitigating soil erosion risk. In this study we explore the spatial distributions of water and wind erosion around Zhangjiakou city which suffers both water and wind erosion contemporaneously, and detect the influence of soil erosion on soil quality. We find that annual wind erosion intensities range 4.99–10.05 t ha−1 yr−1, and annual water erosion intensities range 2.92–4.14 t ha−1 yr−1. Areas with higher potential wind and total erosion risk occur mainly in northwest and southeast Zhangjiakou city, whereas potential water erosion risk is highest in the southwest and central regions. The highest erosion rates are concentrated in gentle parts of the landscape, where agriculture has led to low vegetation cover. Steeper portions of the landscape, which remain forested, have lower erosion rates. These spatial patterns are dominated by higher wind erosion, which correlates with surface soil coarsening and higher water infiltration, whereas the soil water holding capacity decreases with increasing wind erosion rates. In regions with high water infiltration rates, we find the intensity of water erosion weakened. To mitigate risks of soil degradation, suitable erosion measures should be implemented according to the dominant erosion type, which varies in space.