Estimating soil redistribution rates with the RadEro model: A physically based compartmental model for 137Cs analysis in an R package

Quantifying soil redistribution rates cannot be fully addressed by conventional methodologies. Fallout radionuclides (FRNs), particularly ¹³⁷Cs, serve as reliable tracers of soil movement. Numerous models have emerged to estimate soil erosion rates using FRNs, though a versatile, physically-based ¹³⁷Cs model remains absent. We present RadEro, a model designed to estimate soil redistribution rates from ¹³⁷Cs inventories in both ploughed and undisturbed soils, using sectioned or bulk soil profiles based on the mass balance model by Soto and Navas (2004, 2008). The model is built within an R package that offers clear plotting and presentation of results while maintaining a user-friendly format and open-source code. RadEro model accounts for annual ¹³⁷Cs fallout, radioactive decay, stoniness through fine fraction density and effective volume of ¹³⁷Cs and vertical diffusion processes. The RadEro model, validated through sectioned and bulk soil profiles, demonstrates high reliability in simulating experimental inventories, enabling effective land management decisions.