Evolution and Analysis of Landslides in Lowland Areas: The Case Study of Reuil in the Champagne Vineyard Region (Marne, France)

The slopes of the Champagne vineyards are regularly affected by landslides. Given the high societal and economic stakes, these processes cause significant damage and pose a major challenge for the wine industry, forestry and heritage preservation. Numerous studies have already been conducted to understand their behavior and hydrodynamic functioning. They show varied morphologies and a dominant influence of water resources. However, this forcing does not explain the spatial distribution of current landslides, which occur in upper-slope positions, on the steepest terrain recently planted with vines. Using the two shallow landslides at Reuil, located in the heart of the Marne Valley in the Champagne vineyards, as a study site, recent landslide activity is analyzed through a comparative analysis of three DTMs derived from LiDAR HD data and two UAV photogrammetric surveys. This study reveals the affected areas and displaced volumes, which can reach up to 900 m3. Landslide activity was then correlated with regional climatic data. This research shows that landslides are more likely to occur during a period of excessive rainfall following a drier period. Diachronic analysis of aerial images also demonstrates the influence of land use on landslide activity. In particular, land clearing and vineyard operations on the steepest plots constitute a significant anthropogenic forcing affecting slope stability. Taken together, these results provide greater insight into the changing geomorphological dynamics of the Champagne vineyards. On the one hand, they clarify how landslides occur at vineyard plot scale. On the other hand, they provide initial insights into the resilience of stakeholders (winegrowers, etc.) affected by these instabilities.