Insights into linkage between water erosion and Benggang formation: Trajectory tracing from slope to gully

As a special gully landform, Benggang causes severe soil erosion and land degradation in the granite region of South China. In the past few decades, Benggang erosion has received great attention from researchers in terms of formation mechanisms, influencing factors, development processes, and control strategies. From the geomorphic perspective, Benggang essentially represents an extreme soil erosion form, evolving from extensive slope erosion to gully and ultimately initial Benggang erosion. Slope water erosion plays a critical role as both a driving factor and a leading process in Benggang formation and development. However, few reviews have systematically examined the linkage between slope erosion and Benggang formation mechanism. This review summarizes the recent findings from a range of disciplines to show the basic characteristics and evolution stages of Benggang, comprehensively clarify the role of water erosion in driving Benggang formation and development, and propose common formation pathways for Benggang based on water erosion processes. Additionally, we highlight the need for targeted prevention and control measures based on the relative importance of hydraulic and gravitational erosion during Benggang formation and development. Lastly, we propose future research priorities to advance the understanding of Benggang processes, thereby supporting systematic gully erosion research and providing a scientific basis for optimal arrangement of soil and water conservation strategies. This review will contribute to the sustainable management and rational development of Benggang-affected landscapes.