Random and systematic spatial variability of 137Cs inventories at reference sites in South-Central Brazil

Scientia Agricola

Vladia Correchel²  Osny Oliveira Santos Bacchi¹  Klaus Reichardt¹  Isabella Clerici De Maria¹ 

[1] ,USP CENA

关键词: cesium-137;    spatial distribution;    radioisotope;    sediment;    radioactive tracer;    césio-137;    radioisótopo;    sedimento;    traçador radioativo;   

DOI  :  10.1590/S0103-90162005000200013

来源: SciELO

【 摘 要 】

The precision of the 137Cs fallout redistribution technique for the evaluation of soil erosion rates is strongly dependent on the quality of an average inventory taken at a representative reference site. The knowledge of the sources and of the degree of variation of the 137Cs fallout spatial distribution plays an important role on its use. Four reference sites were selected in the South-Central region of Brazil which were characterized in terms of soil chemical, physical and mineralogical aspects as well as the spatial variability of 137Cs inventories. Some important differences in the patterns of 137Cs depth distribution in the soil profiles of the different sites were found. They are probably associated to chemical, physical, mineralogical and biological differences of the soils but many questions still remain open for future investigation, mainly those regarding the adsorption and dynamics of the 137Cs ions in soil profiles under tropical conditions. The random spatial variability (inside each reference site) was higher than the systematic spatial variability (between reference sites) but their causes were not clearly identified as possible consequences of chemical, physical, mineralogical variability, and/or precipitation.

【 授权许可】

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