INFLUENCE OF CLIMATIC CONDITIONS AND SOIL PROPERTIES ON CS-137 VERTICAL-DISTRIBUTION IN SELECTED CHILEAN SOILS

Long-term downward distribution of global fallout Cs-137 was studied i n different soil types, in natural and semi-natural environments of fo ur Chilean climatic zones. The Cs-137 soil content showed an exponenti al decrease with depth; relaxation depth ranged from 0.9 cm in the pol ar climate environment up to 6.8 cm in the mesothermal warm summer one . In the Antarctic and Westpatagonic ecosystems the long freezing peri ods delayed the Cs-137 leaching. In temperate and tropical climate zon es, primarily the rates of annual rainfall and volume of coarse soil p ores control the radionuclide's distribution in the soil profiles.