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| Titel |
Hydrological long-term dry and wet periods in the Xijiang River basin, South China |
| VerfasserIn |
T. Fischer, M. Gemmer, B. Su, T. Scholten |
| 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. 1 ; Nr. 17, no. 1 (2013-01-17), S.135-148 |
| Datensatznummer |
250017680
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| Publikation (Nr.) |
 copernicus.org/hess-17-135-2013.pdf |
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| Zusammenfassung |
In this study, hydrological long-term dry and wet periods are analyzed for
the Xijiang River basin in South China. Daily precipitation data of 118
stations and data on daily discharge at Gaoyao hydrological station at the
mouth of the Xijiang River for the period 1961–2007 are used. At a 24-month
timescale, the standardized precipitation index (SPI-24) for the six
sub-basins of the Xijiang River and the standardized discharge index
(SDI-24) for Gaoyao station are applied. The monthly values of the SPI-24
averaged for the Xijiang River basin correlate highly with the monthly values
of the SDI-24. Distinct long-term dry and wet sequences can be detected.
The principal component analysis is applied and shows spatial disparities in
dry and wet periods for the six sub-basins. The correlation between the
SPI-24 of the six sub-basins and the first principal component score shows
that 67% of the variability within the sub-basins can be explained by dry
and wet periods in the east of the Xijiang River basin. The spatial dipole
conditions (second and third principal component) explain spatiotemporal
disparities in the variability of dry and wet periods. All sub-basins
contribute to hydrological dry periods, while mainly the northeastern
sub-basins cause wet periods in the Xijiang River. We can also conclude that
long-term dry events are larger in spatial extent and cover all sub-basins
while long-term wet events are regional phenomena.
A spectral analysis is applied for the SPI-24 and the SDI-24. The results
show significant peaks in periodicities of 11–14.7 yr, 2.8 yr, 3.4–3.7 yr, and 6.3–7.3 yr.
The same periodic cycles can be found in the
SPI-24 of the six sub-basins but with some variability in the mean
magnitude. A wavelet analysis shows that significant periodicities have been
stable over time since the 1980s. Extrapolations of the reconstructed SPI-24
and SDI-24 represent the continuation of observed significant periodicities
at given magnitudes until 2030. The projected hydrological long-term dry and
wet periods can be used for planning purposes in water resources management.
The applied methodologies prove to be able to identify spatial disparities,
and to detect significant periodicities in hydrological long-term dry and
wet periods in the Xijiang River basin. |
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