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Titel |
Radar rainfall estimation for the post-event analysis of a Slovenian flash-flood case: application of the Mountain Reference Technique at C-band frequency |
VerfasserIn |
L. Bouilloud, G. Delrieu, B. Boudevillain, M. Borga, F. Zanon |
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 ; 13, no. 7 ; Nr. 13, no. 7 (2009-07-29), S.1349-1360 |
Datensatznummer |
250011951
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Publikation (Nr.) |
copernicus.org/hess-13-1349-2009.pdf |
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Zusammenfassung |
This article is dedicated to radar rainfall estimation for the post-event
analysis of a flash flood that occurred on 18 September 2007 in Slovenia.
The utility of the Mountain Reference Technique is demonstrated to quantify
rain attenuation effects that affect C-band radar measurements in heavy
rain. Maximum path-integrated attenuation between 15 and 20 dB were
estimated thanks to mountain returns for path-averaged rain rates between 10
and 15 mm h−1 over a 120-km path. Assuming the reflectivity-attenuation
relationship to be known, the proposed technique allows for estimating an
effective radar calibration correction factor to be accounted for in the
parameterization of the attenuation correction. Screening effects are
quantified using a geometrical calculation based on a digitized terrain
model of the region. The vertical structure of the reflectivity is modeled
with a normalized apparent vertical profile of reflectivity. Implementation
of the radar data processing indicates that: (1) the combined correction for
radar calibration and attenuation effects allows for obtaining satisfactory
radar rain estimates (Nash criterion of 0.8 at the event time scale); (2)
due to the attenuation equation instability, it is however compulsory to
limit the maximum path-integrated attenuation to be corrected to about 10 dB; (3)
the results also prove to be sensitive on the parameterization of
reflectivity-attenuation-rainrate relationships. |
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