This paper presents the results of mathematical analysis of the parame
ters which characterize the change in the availability of Cs-137 for p
lants in soils depending on the physicochemical properties of fallout
from the accidental emission at the Chernobyl NPP. The functions which
describe the dynamics of the forms of Cs-137 in soils and its accumul
ation in meadow vegetation are given, and the associated change in the
se factors is demonstrated.