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| Titel |
Effects of climate variability on savannah fire regimes in West Africa |
| VerfasserIn |
E. T. N'Datchoh, A. Konaré, A. Diedhiou, A. Diawara, E. Quansah, P. Assamoi |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
2190-4979
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| Digitales Dokument |
URL |
| Erschienen |
In: Earth System Dynamics ; 6, no. 1 ; Nr. 6, no. 1 (2015-04-07), S.161-174 |
| Datensatznummer |
250115418
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| Publikation (Nr.) |
 copernicus.org/esd-6-161-2015.pdf |
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| Zusammenfassung |
| The main objective of this work is to investigate at regional scale the
variability in burned areas over the savannahs of West Africa and their links
with the rainfall and the large-scale climatic indexes such as the Southern
Oscillation Index (SOI), Multivariate ENSO Index (MEI), North Atlantic
Oscillation (NAO) and sea surface temperature gradient (SSTG). Daily
satellite products (L3JRC) of burned areas from the SPOT Vegetation sensor at a
moderate spatial resolution of 1 km x 1 km between 2000
and 2007 were analyzed over the West African savannah in this paper. Results
from seasonal analysis revealed a large increase in burned areas from
November to February, with consistent peaks in December at the regional scale.
In addition, about 30% of the pixels are burned at least four times within
the 7-year period. Positive correlations were found between burned areas and
rainfall values obtained from the TRMM satellite over savannahs located above 8° N,
meaning that a wet rainfall season over these regions was favorable to
biomass availability in the next dry season and therefore may induce an
increase in burned areas in this region. Moreover, our results showed a
nonlinear relationship between the large-scale climatic indexes SOI, MEI, NAO
and SSTG and burned-area anomalies. Positive (negative)
correlations between burned areas and SOI (MEI) were
consistent over the Sahel and Sudano-Sahelian areas. Negative correlations with
Atlantic SSTG were significant over the Guinea subregion. Correlations between
burned areas over Sudano-Guinean subregion and all the large-scale indexes
were weak and may be explained by the fact that this subregion had a mean
rainfall greater than 800 mm yr−1 with permanent biomass
availability and an optimal amount of soil moisture favorable to fire
practice irrespective of the climate conditions. The teleconnection with NAO
was not clear and needed to be investigated further. |
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