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| Titel |
Palaeoclimatological perspective on river basin hydrometeorology: case of the Mekong Basin |
| VerfasserIn |
T. A. Räsänen, C. Lehr, I. Mellin, P. J. Ward, M. Kummu |
| 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 ; 17, no. 5 ; Nr. 17, no. 5 (2013-05-31), S.2069-2081 |
| Datensatznummer |
250018889
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| Publikation (Nr.) |
 copernicus.org/hess-17-2069-2013.pdf |
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| Zusammenfassung |
| Globally, there have been many extreme weather events in recent decades. A
challenge has been to determine whether these extreme weather events have
increased in number and intensity compared to the past. This challenge is
made more difficult due to the lack of long-term instrumental data,
particularly in terms of river discharge, in many regions including
Southeast Asia. Thus our main aim in this paper is to develop a river basin
scale approach for assessing interannual hydrometeorological and discharge
variability on long, palaeological, time scales. For the development of the
basin-wide approach, we used the Mekong River basin as a case study area,
although the approach is also intended to be applicable to other basins.
Firstly, we derived a basin-wide Palmer Drought Severity Index (PDSI) from
the Monsoon Asia Drought Atlas (MADA). Secondly, we compared the basin-wide
PDSI with measured discharge to validate our approach. Thirdly, we used
basin-wide PDSI to analyse the hydrometeorology and discharge of the case
study area over the study period of 1300–2005. For the discharge-MADA
comparison and hydrometeorological analyses, we used methods such as linear
correlations, smoothing, moving window variances, Levene type tests for
variances, and wavelet analyses. We found that the developed basin-wide
approach based on MADA can be used for assessing long-term average
conditions and interannual variability for river basin hydrometeorology and
discharge. It provides a tool for studying interannual discharge
variability on a palaeological time scale, and therefore the approach
contributes to a better understanding of discharge variability during the
most recent decades. Our case study revealed that the Mekong has experienced
exceptional levels of interannual variability during the post-1950 period,
which could not be observed in any other part of the study period. The
increased variability was found to be at least partly associated with
increased El Niño Southern Oscillation (ENSO) activity. |
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