Quantifying soil redistribution rates is a global challenge. Radiogenic tracers such as plutonium, namely ^239+240Pu, released to the atmosphere by atmospheric bomb testing in the 1960s are promising tools to quantify soil redistribution. Direct validation of ^239+240Pu as soil redistribution is, however, still missing. Here, we used a unique sediment yield time series in southern Italy, reaching back to the initial fallout of ^239+240Pu to verify ^239+240Pu as a soil redistribution tracer.

The paper demonstrates that the theoretical TCEV (Two Component Extreme Value) distribution can be applied to interpret sediment yield datasets available in Southern Italy. The analysis is based on historical records collected in twelve catchments located in Calabria and Basilicata and followed a hierarchical approach to derive a regional parent distribution from which a return time can be associated with each event. The research was carried out to study soil erosion risk at regional scale.