Identification and assessment of sediment sources and sediment transfer processes in a Mediterranean agroecosystem in the Northern Apennines, Italy

The management of Mediterranean agroecosystems is crucial to prevent and mitigate sediment-related threats like soil erosion, water quality issues, or reservoir sedimentation. Hence, the assessment of sediment dynamics at catchment scale is essential for identifying hotspot areas susceptible to sediment loss. Therefore, the identification of type, extent, and location of sediment sources and sinks is a key prerequisite for assessing sediment yield and transport. This preliminary study is aimed at elaborating an integrated georeferenced inventory map of sediment sources and sinks and related sediment transfer processes within the upper Val d’Arda catchment (Emilian Apennines, Italy), by means of geomorphological field mapping, photointerpretation and remote sensing. Subsequently, the morphological features and the temporal evolution of some representative landforms were analysed using proximal sensing methods and an orthophoto time series analysis covering a fourty six-years period. The results highlight that the study area is highly heterogeneous in terms of type and extent of sediment transfer processes. In particular, the area is widely characterized by several active gravitative processes, e.g. slides, rock/debris falls, debris flows and mudflows, but also wide ancient complex earthflows with evidence of partial reactivation and retrogressive evolution during the observed time period. Moreover, we identified several rill-interril, piping and gully systems, whose genesis and evolution appeared to be mainly controlled by lithology and land-use. In some cases these systems have evolved into badlands, with a high potential of soil loss and sediment production. Finally, we identified several bank erosion source areas within the main fluvial systems. In this study we implemented an integrated cascade methodology in order to identify the main processes involved in the sediment production and the related downslope transfer of sediments. Further analysis will be carried out in order to investigate process-specific susceptibilities and the role of different environmental variables as controlling factors.