Stone Wall Inventory: A Combined Remote and In Situ Approach Applied in a Protected Landscape

Stone walls are vital components of Mediterranean rural landscapes, but they are increasingly threatened by land abandonment and the loss of traditional maintenance practices. This study presents an integrated approach for detecting and mapping stone walls within the Appennino Lucano Val d’Agri Lagonegrese National Park (southern Italy), recognized as an area of outstanding importance for the conservation of biodiversity and cultural landscapes. The adopted methodology relies on a procedure that combines field surveys with a dual remote sensing framework utilizing very-high-resolution SkySat imagery and multi-date Copernicus Sentinel-2 data. SkySat imagery was used for the semi-automated detection of stone wall-related features based on morpho-textural characteristics, complemented by photointerpretation through Google Earth, Google Maps, and Google Street View, whereas Sentinel-2 data were used to screen vegetation conditions in the areas surrounding the inventoried stone walls and terraces. As an additive investigation, the historical tratturi (ancient transhumance routes) network was used as a historically informed spatial framework to identify priority corridors for visual inspection. The integrated approach resulted in an inventory of 374 georeferenced stone-wall occurrences distributed across different landscape contexts. Sentinel-2 analysis showed that approximately 16% of the persistent within-season vegetation anomalies detected across the Park spatially co-occurred within landscape-scale 1-km buffers surrounding the inventoried stone walls and terraces. The resulting georeferenced database integrates spatial and ecological data within a GIS environment across 29 municipalities. Overall, the proposed workflow provides an operational framework for rural-heritage documentation, landscape-scale screening, and the prioritization of monitoring and conservation activities in Mediterranean environments.