Use of 7Be measurements to estimate rates of soil loss from cultivated land: Testing a new approach applicable to individual storm events occurring during an extended period

The techniques available for documenting rates and patterns of soil redistribution in the landscape have many limitations and the value of those employing fallout radionuclides (FRNs), including caesium-137 (137Cs) and excess lead-210 (210Pbex) is being increasingly recognized. However, the use of 137Cs and 210Pbex measurements is best suited to investigations of longer-term soil redistribution rates (i.e., 50–60 years for 137Cs and 100 years for 210Pbex). For many purposes, a much shorter timeframe is required. Beryllium-7 (7Be), another FRN (half-life 53 days), offers the potential to document soil redistribution associated with individual events or short periods of heavy rainfall. However, existing approaches for using 7Be possess important limitations related to both the timing of the study period and its length. This contribution reports the development of a new approach that permits estimation of the soil loss associated with all individual events or short periods of rainfall occurring during a study period extending over a year or more. The approach was validated using data collected from an erosion plot located in southern Italy. The close agreement of the measured and estimated values demonstrates the validity of the new approach which has the potential to greatly increase the scope for using 7Be measurements to document short-term soil redistribution associated with individual storm events.