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Titel |
Stratified analysis of satellite imagery of SW Europe during summer 2003: the differential response of vegetation classes to increased water deficit |
VerfasserIn |
A. Lobo, P. Maisongrande |
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 ; 10, no. 2 ; Nr. 10, no. 2 (2006-02-28), S.151-164 |
Datensatznummer |
250007979
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Publikation (Nr.) |
copernicus.org/hess-10-151-2006.pdf |
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Zusammenfassung |
The extraordinarily warm and dry summer experienced in SW Europe in 2003
provides an interesting case study for the analysis of the response of
regional-scale vegetation variables to drier and hotter conditions. SW
Europe includes a boundary between phytogeographic and climatic regions
(Oceanic and Mediterranean) that differ in terms of summer precipitation,
which let us compare the response of different vegetation types. In
addition, some scenarios predict summer conditions such as those of 2003 to
be common by the latter decades of the 21st century in this region. We
have analyzed a monthly series of regional fields of normalized difference
vegetation index from the VEGETATION-SPOT5 instrument, from 1999 to 2003. We
show that negative anomalies of vegetation index in summer 2003 were larger
for herbaceous vegetation of the Oceanic climate region and for deciduous
forests. The vegetation index of August 2003 in the Mediterranean climate
region was also significantly lower than normal values in August 1999–2002,
albeit the anomalies were small in absolute value. We compared August NDVI,
as a measure of the vegetation response, to the difference between total
summer precipitation and total summer potential evapotranspiration, as a
measure of atmospheric water stress. Our results indicate that water stress
is a major factor structuring the geographic variability of NDVI in this
region. In accordance with these results, the analysis of the data of 2003
indicate that the increased water stress was a key factor of the observed
anomalies of vegetation index. |
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