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| Titel |
Estimating surface fluxes over middle and upper streams of the Heihe River Basin with ASTER imagery |
| VerfasserIn |
W. Ma, Y. Ma, Z. Hu, Z. Su, J. Wang, H. Ishikawa |
| 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. 5 ; Nr. 15, no. 5 (2011-05-06), S.1403-1413 |
| Datensatznummer |
250012777
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| Publikation (Nr.) |
 copernicus.org/hess-15-1403-2011.pdf |
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| Zusammenfassung |
| Land surface heat fluxes are essential measures of the
strengths of land-atmosphere interactions involving energy, heat and water.
Correct parameterization of these fluxes in climate models is critical.
Despite their importance, state-of-the-art observation techniques cannot
provide representative areal averages of these fluxes comparable to the
model grid. Alternative methods of estimation are thus required. These
alternative approaches use (satellite) observables of the land surface
conditions. In this study, the Surface Energy Balance System (SEBS)
algorithm was evaluated in a cold and arid environment, using land surface
parameters derived from Advanced Spaceborne Thermal Emission and Reflection
Radiometer (ASTER) data. Field observations and estimates from SEBS were
compared in terms of net radiation flux (Rn), soil heat flux
(G0), sensible heat flux (H) and latent heat flux (λE) over a heterogeneous
land surface. As a case study, this methodology was applied to the
experimental area of the Watershed Allied Telemetry Experimental Research
(WATER) project, located on the mid-to-upstream sections of the Heihe River
in northwest China. ASTER data acquired between 3 May and 4 June 2008,
under clear-sky conditions were used to determine the surface fluxes.
Ground-based measurements of land surface heat fluxes were compared with
values derived from the ASTER data. The results show that the derived
surface variables and the land surface heat fluxes furnished by SEBS in
different months over the study area are in good agreement with the observed
land surface status under the limited cases (some cases looks poor results).
So SEBS can be used to estimate turbulent heat fluxes with acceptable
accuracy in areas where there is partial vegetation cover in exceptive
conditions. It is very important to perform calculations using ground-based
observational data for parameterization in SEBS in the future. Nevertheless,
the remote-sensing results can provide improved explanations of land surface
fluxes over varying land coverage at greater spatial scales. |
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