黄土残塬沟壑区切沟内部侵蚀及植被自然恢复对极端暴雨的响应OA

[Objective]This study clarifies the response characteristics of geomorphic erosion processes within gullies to extreme rainstorm events in the loess plateau gully erosion region and reveals the spatiotemporal dynamics of early-stage natural vegetation recovery and its response patterns to topographic factors after rainstorm disturbances,providing a scientific basis for evaluating geomorphic stability and ecological restoration potential of the Loess Plateau under extreme weather conditions.[Methods]Two loess plateaus,Zhongduo Tableland and Shiquan Tableland in the Loess Plateau gully erosion region in western Shanxi Province,were selected as the study areas.Focusing on the extreme rainstorm event in 2021,13 typical gullies dissecting the plateaus were identified.Multi-temporal unmanned aerial vehicle(UAV)monitoring data from 2021 to 2024 were used to analyze the dynamic changes in bare soil area and the recovery processes of fractional vegetation cover(FVC)within the gullies.The impact of topographic factors on the gully internal erosion and vegetation recovery processes was quantitatively analyzed.[Results]The extreme rainstorms induced severe erosion within gullies,with newly exposed bare soil area accounting for 5.92%of the total gully area,and reaching up to 18.73%in individual gullies.Strong ecosystem recovery capacity was observed inside the gullies after the rainstorm.Three years later,only 17.68%of the newly exposed bare soil remained,and the areas with medium-to-high FVC increased to over 60%.Erosion intensity was higher on steep(35°～45°)and very steep slopes(>45°),accounting for 17.92%and 68.52%of the newly exposed bare soil,respectively.Shaded slopes suffered greater damage during the rainstorm than sunny slopes,but demonstrated stronger vegetation recovery capacity.[Conclusion]The internal gullies in the Loess Plateau gully erosion region responded strongly to extreme rainstorms.Rainstorms induced intense erosion,with newly exposed bare soil accounting for 5.92%,mainly distributed in the middle and lower slopes and the gully bottoms.After the rainstorm,the gully system exhibited strong natural recovery capacity,with a notable increase in medium-to-high FVC.Vegetation recovery was controlled by topographic factors:slope gradient affected recovery rates,while slope aspect resulted in pronounced spatial differentiation,with better recovery observed on shaded slopes than on sunny slopes.