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| Titel |
Use of mobile gammaspectrometry for estimation of texture at regional scale |
| VerfasserIn |
C. Dierke, U. Werban, P. Dietrich |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250065853
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| Zusammenfassung |
| In the last years gamma-ray measurements from air and ground were increasingly used for
spatial mapping of physical soil parameters. Many applications of gamma-ray measurements
for soil characterisation and in digital soil mapping (DSM) are known from Australia or
single once from Northern America. During the last years there are attempts to use that
method in Europe as well.
The measured isotope concentration of the gamma emitter 40K, 238U and 232Th in soils
depends on different soil parameters, which are the result of composition and properties of
parent rock and processes during soil geneses under different climatic conditions. Grain size
distribution, type of clay minerals and organic matter are soil parameters which influence
directly the gamma-ray concentration. From former studies we know, that there are site
specific relationships at the field scale between gamma-ray measurements and soil
properties. One of the target soil properties in DSM is for e.g. the spatial distribution of
texture at the landscape scale. Thus there is a need of more regional understanding of
gamma-ray concentration and soil properties with regard to the complex geology of
Europe.
We did systematic measurements at different field sites across Europe to investigate the
relationship between the concentrations of gamma radiant and grain size. The areas are
characterised by different pedogenesis and varying clay content. For the measurement we
used a mobile 4l Na(I) detector with GPS connection, which is mounted on a sledge and can
be towed across the agricultural used plane. Additionally we selected points for soil sampling
and analysis of soil texture.
For the interpretation we used the single nuclide concentration as well as the
ratios. The results show site specific relationships dependent from source material.
At soils developed from alluvial sediments the K/Th ratio is an indicator for clay
content at regional scale. At soils developed from loess sediments Th can be used do
discriminate between fine (clay + silt) and coarse (sand) fraction. This knowledge will
led to a more conceptual understanding of gamma-ray measurements at regional
scale.
These activities are done within the iSOIL project. iSOIL- Interactions between soil
related sciences – Linking geophysics, soil science and digital soil mapping is a Collaborative
Project (Grant Agreement number 211386) co-funded by the Research DG of the European
Commission within the RTD activities of the FP7 Thematic Priority Environment; iSOIL is
one member of the SOIL TECHNOLOGY CLUSTER of Research Projects funded by the
EC. |
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