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Titel |
On the use of AMSU-based products for the description of soil water content at basin scale |
VerfasserIn |
S. Manfreda, T. Lacava, B. Onorati, N. Pergola, M. Leo, M. R. Margiotta, V. Tramutoli |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 15, no. 9 ; Nr. 15, no. 9 (2011-09-09), S.2839-2852 |
Datensatznummer |
250012957
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Publikation (Nr.) |
copernicus.org/hess-15-2839-2011.pdf |
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Zusammenfassung |
Characterizing the dynamics of soil moisture fields is a key
issue in hydrology, offering a strategy to improve our
understanding of complex climate-soil-vegetation interactions.
Besides in-situ measurements and hydrological models, soil
moisture dynamics can be inferred by analyzing data acquired by
sensors on board of airborne and/or satellite platforms. In this
work, we investigated the use of the National Oceanic and
Atmospheric Administration – Advanced Microwave Sounding Unit-A
(NOAA-AMSU-A) radiometer for the remote characterization of soil
water content. To this aim, a field measurement campaign, lasted
about three months (3 March 2010–18 May 2010), was carried out
using a portable time-domain reflectometer (TDR) to get soil water
content measures over five different locations within an
experimental basin of 32.5 km2, located in the South of
Italy. In detail, soil moisture measurements were carried out
systematically at the times of satellite overpasses, over two
square areas of 400 m2, a triangular area of
200 m2 and two transects of 60 and 170 m, respectively.
Each monitored site is characterized by different land covers and
soil textures, to account for spatial heterogeneity of land
surface. Afterwards, a more extensive comparison (i.e. analyzing a
5 yr data time series) was made using soil moisture simulated
by a hydrological model. Measured and modeled soil moisture data
were compared with two AMSU-based indices: the Surface Wetness
Index (SWI) and the Soil Wetness Variation Index (SWVI). Both time
series of indices have been filtered by means of an exponential
filter to account for the fact that microwave sensors only provide
information at the skin surface. This allowed to understand the
ability of each satellite-based index to account for soil moisture
dynamics and to understand its performances under different
conditions. As a general remark, the comparison shows a higher
ability of the filtered SWI to describe the general trend of soil
moisture, while the SWVI can capture soil moisture variations with
a precision that increases at the higher values of SWVI. |
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