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| Titel |
Characteristics of 2-D convective structures in Catalonia (NE Spain): an analysis using radar data and GIS |
| VerfasserIn |
M. Barnolas, T. Rigo, M. C. Llasat |
| 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 ; 14, no. 1 ; Nr. 14, no. 1 (2010-01-21), S.129-139 |
| Datensatznummer |
250012151
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| Publikation (Nr.) |
 copernicus.org/hess-14-129-2010.pdf |
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| Zusammenfassung |
| Flood simulation studies use spatial-temporal rainfall data input into
distributed hydrological models. A correct description of rainfall in space
and in time contributes to improvements on hydrological modelling and
design. This work is focused on the analysis of 2-D convective structures
(rain cells), whose contribution is especially significant in most flood
events. The objective of this paper is to provide statistical descriptors
and distribution functions for convective structure characteristics of
precipitation systems producing floods in Catalonia (NE Spain). To achieve
this purpose heavy rainfall events recorded between 1996 and 2000 have been
analysed. By means of weather radar, and applying 2-D radar algorithms a
distinction between convective and stratiform precipitation is made. These
data are introduced and analyzed with a GIS. In a first step different
groups of connected pixels with convective precipitation are identified.
Only convective structures with an area greater than 32 km2 are
selected. Then, geometric characteristics (area, perimeter, orientation and
dimensions of the ellipse), and rainfall statistics (maximum, mean, minimum,
range, standard deviation, and sum) of these structures are obtained and
stored in a database. Finally, descriptive statistics for selected
characteristics are calculated and statistical distributions are fitted to
the observed frequency distributions. Statistical analyses reveal that the
Generalized Pareto distribution for the area and the Generalized Extreme
Value distribution for the perimeter, dimensions, orientation and mean areal
precipitation are the statistical distributions that best fit the observed
ones of these parameters. The statistical descriptors and the probability
distribution functions obtained are of direct use as an input in spatial
rainfall generators. |
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