The study of the distribution of the 137Cs is a popular methodology to estimate soil erosion rates. In a high plain area site in the Italian Central Alps (Valchiavenna), soils have been sampled in 135 points. The samples were measured by γ spectrometry using a HPGe detector. Early results showed a high spatial variability of the superficial distribution of 137Cs, however the activity of 137Cs tends to become homogeneous in the deeper soils’ layers. In order to map 137Cs activity in the topsoil, a regression model has been fitted using topographical descriptors, derived from an high resolution DEM, and soil properties. The Poisson model has been effective in modelling the relation between 137Cs activity, soil properties and topographical descriptors. When combined in a regression kriging procedure the model has been able to explain roughly 0.65 of data variance. Moreover when used on short topographic gradients, the Poisson model is able to explain up to the 0.81 of the 137Cs activity variance, thus evidencing the strong relation between the distribution of this element and soil erosion. These results encourage the use of 137Cs as a tracer of soil erosion in Alpine soils
Ballabio, C., Curioni, G., Clemenza, M., Comolli, R., Previtali, E. (2009). Study of the spatial distribution of 137Cs in Alpine soils. STUDI TRENTINI DI SCIENZE NATURALI, 85.
Study of the spatial distribution of 137Cs in Alpine soils
BALLABIO, CRISTIANO;CLEMENZA, MASSIMILIANO;COMOLLI, ROBERTO;Previtali, E.
2009
Abstract
The study of the distribution of the 137Cs is a popular methodology to estimate soil erosion rates. In a high plain area site in the Italian Central Alps (Valchiavenna), soils have been sampled in 135 points. The samples were measured by γ spectrometry using a HPGe detector. Early results showed a high spatial variability of the superficial distribution of 137Cs, however the activity of 137Cs tends to become homogeneous in the deeper soils’ layers. In order to map 137Cs activity in the topsoil, a regression model has been fitted using topographical descriptors, derived from an high resolution DEM, and soil properties. The Poisson model has been effective in modelling the relation between 137Cs activity, soil properties and topographical descriptors. When combined in a regression kriging procedure the model has been able to explain roughly 0.65 of data variance. Moreover when used on short topographic gradients, the Poisson model is able to explain up to the 0.81 of the 137Cs activity variance, thus evidencing the strong relation between the distribution of this element and soil erosion. These results encourage the use of 137Cs as a tracer of soil erosion in Alpine soils
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