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| Titel |
Laboratory and in situ experiments on soil samples for determination of pedotransferfunctions |
| VerfasserIn |
Said Al Hagrey, Tina Wunderlich, Hauke Petersen, Michael Lay, Wolfgang Rabbel, Harald Stümpel |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250035022
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| Zusammenfassung |
| One major objective of the iSOIL project is the determination of so called pedotransferfunctions
linking measured geophysical parameters (for example conductivity and permittivity) to soil
parameters (like clay content or salinity). Some empirical, site-dependent pedophysical
functions are already developed, but there are limitations of validation regarding soil types,
applied methodology, measuring boundaries etc. To develop new and to extend
known models laboratory and in situ experiments of different kinds should be carried
out.
For the laboratory experiments we collected disturbed samples (50kg each) of different soil
types and from different depths. These samples are dried, crushed and then saturated with
rain water in steps of approximately 2-5% volumetric water content. After each saturation
step the samples are mixed thoroughly until they are assumed to be homogeneously and filled
in a cylindrical container. We then conduct GPR (Ground Penetrating Radar) measurements
with a 1.5GHz antenna using a metal plate underneath the container as a reflector to get the
permittivity of the soil at each water content step. Also geoelectrical measurements
determining the resistivity are carried out in different electrode spacings and configurations
for each saturation step. For the whole series of measurements the water content is controlled
by gravimetrical methods and TDR (Time-domain reflectometry) measurements.
Different empirical and hypothetical pedotransferfunctions have been fitted to the
electrical (resistivity) and dielectrical (permittivity, radar velocity) parameters and
discussed.
Acknowledgement: 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. |
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