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| Titel |
Soil moisture mapping at Bubnow Wetland using L-band radiometer (ELBARA III) |
| VerfasserIn |
Mateusz Lukowski, Mike Schwank, Radoslaw Szlazak, Andreas Wiesmann, Wojciech Marczewski, Boguslaw Usowicz, Jerzy Usowicz, Edyta Rojek, Charles Werner |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250126943
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| Publikation (Nr.) |
 EGU/EGU2016-6739.pdf |
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| Zusammenfassung |
| The study of soil moisture is a scientific challenge. Not only because of large diversity of
soils and differences in their water content, but also due to the difficulty of measuring,
especially in large scale. On this field of interest several methods to determine the content of
water in soil exists. The basic and referential is gravimetric method, which is accurate, but
suitable only for small spatial scales and time-consuming. Indirect methods are faster, but
need to be validated, for example those based on dielectric properties of materials (e.g. time
domain reflectometry - TDR) or made from distance (remote), like brightness temperature
measurements. Remote sensing of soil moisture can be performed locally (from towers,
drones, planes etc.) or globally (satellites). These techniques can complement and help to
verify different models and assumptions. In our studies, we applied spatial statistics
to local soil moisture mapping using ELBARA III (ESA L-band radiometer, 1.4
GHz) mounted on tower (6.5 meter height). Our measurements were carried out in
natural Bubnow Wetland, near Polesie National Park (Eastern Poland), during spring
time. This test-site had been selected because it is representative for one of the
biggest wetlands in Europe (1400 km2), called “Western Polesie”, localized in
Ukraine, Poland and Belarus. We have investigated Bubnow for almost decade,
using meteorological and soil moisture stations, conducting campaigns of hand-held
measurements and collecting soil samples. Now, due to the possibility of rotation at different
incidence angles (as in previous ELBARA systems) and the new azimuth tracking
capabilities, we obtained brightness temperature data not only at different distances
from the tower, but also around it, in footprints containing different vegetation and
soil types. During experiment we collected data at area about 450 m2 by rotating
ELBARA’s antenna 5-175˚ in horizontal and 30-70˚ in vertical plane. This type of
approach allows combining multiple independent measurements (performed nearly
simultaneously) to one consistent soil moisture map. Spatial statistics helps with correcting
blind spots or distortions causes by assembly elements, especially on corners of
ELBARA’s tower. Moreover, using this technique we can observe distribution of
soil moisture with time dependency. In order to validate our data, the results were
compared with measurements obtained by means of the TDR method. The presented
approach enables better understanding the soil moisture spatial distribution over a
particular local area of interests, before extending soil water assessments on larger
areas.
The work was partially funded under two ESA projects:
1) “ELBARA_PD (Penetration Depth)” No. 4000107897/13/NL/KML, funded by the
Government of Poland through an ESA-PECS contract (Plan for European Cooperating
States)
2) “Technical Support for the fabrication and deployment of the radiometer ELBARA-III
in Bubnow, Poland” No. 4000113360/15/NL/FF/gp |
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