Use of 7Be to document soil erosion associated with a short period of extreme rainfall

Sorption behaviour of beryllium-7 and implications for its use as a sediment tracer

“…The potential for 7 Be mobility under common, oxic field conditions No detectable 7 Be was found to be extracted by the artificial rainwater solution (pH 5.6) in all experimental soils, thus, providing confidence in the use of 7 Be as a tracer under common, oxic field conditions. On the basis of this behaviour, robust estimation of soil erosion at the slope scale using 7 Be can, therefore, be expected (Blake et al, 1999;Schuller et al, 2006;Sepulveda et al, 2008;Wilson et al, 2003). However, one potential area of uncertainty lies in the sorption dynamics after runoff initiation.…”

“…The short half-life of 7 Be (t 1/2 = 53.3 days) lends itself to tracing short-term soil redistribution complimenting medium-term estimates derived from 137 Cs (t 1/2 = 30.2 years) and 210 Pb (t 1/2 =22.3 years). By determining the difference in 7 Be areal activity at a sampling point in comparison to a reference baseline and considering the 7 Be depth profile, quantification of soil redistribution at the hill slope scale can be achieved on an event basis (Blake et al, 1999;Sepulveda et al, 2008). More recently, detailed consideration of 7 Be fallout, erosivity of rainfall, radionuclide decay and temporal variation of the depth profile has allowed 7 Be to be used to determine soil erosion over longer timescales (Walling et al, 2009).…”

A review of phosphorus and sediment release from Irish tillage soils, the methods used to quantify losses and the current state of mitigation practice

“…Given the time and cost involved in establishing and operating plot experiments, and the fact that data available from them are limited, attention has been directed towards the use of environmental radionuclides for documenting erosion rates (Sepulveda et al 2008) Cs and up to 100 years for unsupported 210 Pb) estimates of both the magnitude and spatial distribution of soil redistribution rates generated by sheet and rill erosion, by means of a single site visit (Blake et al 1999). Due to its long retention time on soil particles once absorbed, 137 Cs (t 1/2 = 30.1 years) has the disadvantage of not being suitable for the investigation of erosion resulting from individual events occurring over short periods, and is unable to distinguish between tillage and water erosion.…”

Sediment dynamics during the rainy season in tropical highland catchments of central Mexico using fallout radionuclides

“…It is strongly fixed to the particles and mostly remains at the soil surface (i.e., in the uppermost 2 cm of the soil). Given its short half-life (T 1/2 = 53 days), it is used to document soil erosion over the short term (e.g., Sepulveda et al, 2008).…”