Quantitative model of soil erosion rates using 137Cs for uncultivated soil

By using the mass balances model and by introducing an erosion constant (mean annual relative loss of 137 Cs) and depth distribution function of 137 Cs in soil, a quantitative model of soil erosion rate using 137 Cs loss was developed for uncultivated soils. Depth distribution patterns of 137 Cs in the soil profile, sampling years, and the amount of 137 Cs fallout each year were considered.The model shows that the estimated rate of soil erosion is controlled mainly by the distribution pattern of 137 Cs in the soil profile. By inputting different depth distribution functions of 137 Cs, the year of sampling and the different input fraction of total fallout value each year, several simulation results of soil loss were given.The results of numerical simulation proved that the relationship between the rate of soil loss and 137 Cs depletion is neither linear nor logarithmic. They are dependent on the distribution patterns of 137 Cs in the soil profile, sampling year, and input fraction of total fallout value.