Assessment of the effects of ecological restoration projects on soil wind erosion in northern China in the past two decades

Wind erosion is a typical natural hazard in arid and semiarid regions. In recent decades, China has shown significant changes of greening trend due to a range of several ecological restoration projects (ERPs), Meanwhile, the wind erosion in northern China changed significantly. The debate about whether climatic change or ERPs dominated the variations in wind erosion was never truly resolved, which seriously affect the deployment of ERPs in the future, and it is a concerns of both academia and the Chinese government. To address this debate, we distinguished the ERPs' effects on wind erosion from the climate change background by modeling the wind erosion under the different surface vegetation scenarios with the revised wind erosion equation (RWEQ) that was validated by our field observations. The simulated results shown that relative to the benchmark year (2000), the ERPs caused a rate of decrease of 17.77% of wind erosion modulus (WEM) in northern China during the period of 2001 to 2019, which occupied approximately 61% of the total decrease of WEM by ERPs and climatic fluctuations. This result means that the ERPs played the dominant role in wind erosion decreasing overall. Considering the effects of ERPs to wind erosion, the wind erosion intensity, the climatic fluctuation, and vegetation carrying capacity, this study concluded that the Gurbantunggut Desert, the Otindag Sandy Land, the Lop Nor, the Gashun Gobi Desert, the Mongolia Gobi Desert and the Hexi Corridor are the potential regions for ERP deployment in the future. We believe this study should provide robust evidence to resolve the debate on what dominates the variations in wind erosion processes in northern China, and give the valuable suggestions for ecological restoration project deployment in the future.