[The quantitative parameters of the vertical migration of radionuclides in the soils in different types of meadows]

The two-component convective-diffusional model was used for determination of vertical migration parameters of 90Sr [correction of 90Cs] and 137Cs in meadow ecosystems and dependence from meadow type and soil properties was shown. The migration coefficients decrease in the order: peat land, lowland meadows, flood-plain meadows, dry meadows. The ecological half-life in the root zone ranges from 55 to 143 y for dry meadows and from 15 to 21 y for peat lands. Analogous parameters for 90Sr was 30-96 and 13-18 y, respectively. Since 1987 to 1994 the ecological half-life of 137Cs increased by a factor of 1.7-6.0.