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 137 Cs, serve as reliable tracers of soil movement. Numerous models have emerged to estimate soil erosion rates using FRNs, though a versatile, physically-based 137 Cs model remains absent. We present RadEro, a model designed to estimate soil redistribution rates from 137 Cs 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 137 Cs fallout, radioactive decay, stoniness through fine fraction density and effective volume of 137 Cs 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. • RadEro the first 137 Cs mass balance model developed in R. • The model estimates soil redistribution rates in ploughed and undisturbed soils. • RadEro simulates 137 Cs fallout and decay, vertical diffusion, and soil erosion and deposition rates. • The R package generates graphs of the simulated and measured 137 Cs soil profiles.