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| Titel |
Modeling of rainfall events and trends through multifractal analysis on the Ebro River Basin |
| VerfasserIn |
Jose Luis Valencia, Ana María Tarquis, Antonio Saá-Requejo, Maria Villeta, Jose Maria Gasco |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250108018
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| Publikation (Nr.) |
 EGU/EGU2015-7747.pdf |
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| Zusammenfassung |
| Water supplies in the Ebro River Basin present high seasonal fluctuations, with extreme
rainfall events during autumn and spring, and demands are increasingly stressed during
summer. At the same time, repeated anomalous annual fluctuations in recent decades have
become a serious concern for regional hydrology, agriculture and several related industries in
the region. In fact, it has had a devastating impact, both socially and economically. In addition
it has resulted in debate over the changing seasonal patterns of rainfall and the increasing
frequency of extreme rainfall events.
The aim of this work is to evaluate these challenges on the Ebro River Basin.For this
purpose, 132 complete and regular spatial rainfall daily datasets (from 1931 to 2009) were
analyzed. Each dataset corresponds to a grid of 25 km x 25 km and belongs to the area
studied.
First, classical statistical tests were applied to the series at annual scale to check the
randomness and trends. No trends where found. Then, we analyzed the change in
the rainfall variability pattern in the Ebro River Basin. We have used universal
multifractal (UM) analysis, which estimates the concentration of the data around
the precipitation average (C1, codimension average), the degree of multiscaling
behavior in time (α index) and the maximum probable singularity in the rainfall
distribution (γs). Daily rainfall series were subdivided (1931–1975 and 1965–2009) to
study the difference between the two periods in these three UM parameters, in an
attempt to relate them to geographical coordinates and relative positions in the river
basin.
The variations observed in C1 and α in some areas of the Ebro River Basin indicate that
a precipitation regime change has begun in the last few decades, and therefore,
this change should be considered in terms of its potential effects on the social and
economical development of the region. This confirms some postulates drawn by
conservative scientists who reject a catastrophic interpretation and suggest that there is a
weak trend towards a new climatic situation that includes the precipitation regime. |
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