Experience of mapping spatial structure of Cs-137 in natural landscape and patterns of its distribution in soil toposequence

Mapping of 137Cs activity was performed to test the idea of a non-random (deterministic) character of distribution of chemical elements and their compounds in space. Spatial distribution of the particular chemical elements and their compounds is proposed to be treated as a continuous single whole numerical field with a specified structure where each value and its change are related to the others. Direct measurements of the Chernobyl 137Cs activity and its mapping within the study plots confirmed the regular character of the radionuclide spatial structure on different scale levels. The observed spatial structure was suggested to reflect the secondary transformation of the initial fallout due to lateral and vertical migration of 137Cs with water as the main agent of physical and chemical migration related both to meso- and micro-relief features. Proposed deterministic approach is believed to stimulate development of the non-stochastic mathematical and physical methods in the analysis and forecast of spatial structure of geochemical fields.

Research Highlights
► Detailed mapping of 137Cs confirmed regular structure of the soil contamination field.
► Polycentric structure was followed downscale using the grids of 5, 2, 1, and 0.2 m.
► The structure remained stable within the study period.
► It was suggested that 137Cs secondary redistribution was related to relief.