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| Titel |
Use of Physio-Hydrological Units for SMOS Validation at the Valencia Anchor Station Study Area |
| VerfasserIn |
C. Millan-Scheiding, C. Antolín, J. Marco, M. P. Soriano, E. Torre, F. Requena, E. Carbó, A. Cano, E. Lopez-Baeza |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250029974
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| Zusammenfassung |
| The SMOS space mission will soil moisture over the continents and ocean surface salinity
with the sufficient resolution to be used in global climate change studies.
With the aim of validating SMOS land data and products at the Valencia Anchor Station
site (VAS) in a Mediterranean Ecosystem area of Spain, we have designed a sample
methodology using a subdivision of the landscape in environmental units related to the
spatial variability of soil moisture (Millán-Scheiding, 2006; Lopez-Baeza, et al.
2008). These physio-hydrological units are heterogeneously structured entities which
present a certain degree of internal uniformity of hydrological parameters. The units
are delimited by integrating areas with the same physio-morphology, soil type,
vegetation, geology and topography (Flugel, et al 2003; Millán-Scheiding et al,
2007). Each of these units presented over the same pedological characteristics,
vegetation cover, and landscape position should have a certain degree of internal
uniformity in its hydrological parameters and therefore similar soil moisture (SM). The
main assumption for each unit is that the dynamical variation of the hydrological
parameters within one unit should be minimum compared to the dynamics of another
unit.
This methodology will hopefully provide an effective sampling design consisting of a
reduced number of measuring points, sparsely distributed over the area, or alternatively, using
SM validation networks where each sampling point is located where it is representative of the
mean soil moisture of a complete unit area.
The Experimental Plan for the SMOS Validation Rehearsal Campaign at the VAS area of
April-May 2008 used this environmental subdivision in the selection and sampling
of over 21.000 soil moisture points in a control area of 10 x 10 km2. The ground
measurements were carried out during 4 nights corresponding to a drying out period of the
soil. The sampling consisted of 700 plots with 4 volumetric SM cylinders and 7
Delta-T Theta Probe measurements (with 3 repetitions each), covering the whole
area.
This experimental campaign permits the characterization of the soil moisture distribution
within each physio-hydrological unit and results in a soil moisture map of the VAS site.
All of it used for the validation of the aircraft observations done throughout the
campaign.
The ground measurement results obtained indicate that soil properties and vegetation
cover are the parameters of the physio-hydrological units that most influence the moisture of
the soil. This relationship will permit a more simple delimitation of the physio-hydrological
Units and a reduction of the number of sample points for the calibration/validation of SMOS
products.
References:
Lopez-Baeza, E., R. Acosta, M.C. Antolin, F. Belda, A. Cano, E. Carbo, M. Crapeau, A.
Fidalgo S. Juglea, Y. Kerr, B. Martinez, C. Millan-Scheiding, D. Rodriguez, K. Saleh, J.
Sanchis, J.-P. Wigneron(10), Other Contributors: J.E. Balling, C. Domenech, EOLAB, A.G.
Ferreira J. Ferrer, J. Grant, J. Marco C. Narbon, B. Navascues, OCEANSNELL, E.
Rodriguez-Camino, N. Skou, S. Søbjærg, P. Soriano, J. Tamayo, S. Tauriainen, E. Torre G.
Torregrosa, A. Velazquez Blazquez, S. Vidal (2008): Validation of SMOS Products over
Mediterranean Ecosystem Vegetation at the Valencia Anchor Station Reference Area. SMOS
Cal/Val AO I.D. no. 3252. Experimental Plan SMOS Validation Rehearsal Campaign.
University of Valencia, April 2008
Millan-Scheiding, C. (2006): Aproximación a la Humedad del Suelo en el Altiplano de
Requena-Utiel. Preparación para la Campaña de Cal/Val de la Misión Espacial SMOS.
Trabajo de Investigación de III Ciclo. Universidad de Valencia.
Millán-Scheiding, C., C. Antolín, A. Cano, E. López-Baeza (2007): Uso de
Unidades Fisio-Hidrológicas en la Monitorización de la Humedad del Suelo con
SMOS. III Simposio Nacional sobre el Control de la Degradación de Suelos y la
Desertificación. Costa Calma (Pájara), Fuerteventura, 16 al 20 de Septiembre 2007 |
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