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| Titel |
Areal rainfall construction and estimation of extreme quantiles. |
| VerfasserIn |
David Penot, Emmanuel Paquet, Michel Lang |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250087778
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| Publikation (Nr.) |
 EGU/EGU2014-1835.pdf |
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| Zusammenfassung |
| Areal rainfall estimation and extrapolation to extremes is a key issue for catchment flood
study. It is a tricky problem which deals with spatial interpolation (to build an estimate at the
catchment’s scale based on few rain gauges only), and probabilistic extrapolation (for
extreme values estimation).
In this study, several methods to build an areal rainfall estimation are compared. The first
method is the commonly used Thiessen polygons. A second way to build an areal
rainfall relies on the SPAZM method [Gottardi, 2012], in which daily rain fields are
reconstructed at a 1km2 resolution, with an interpolation scheme integrating the altitude
of the pixel and the weather type of the day. These two methods are compared to
the stochastic rain field simulator SAMPO [Leblois et Creutin, 2013], which is an
adaptation of the turning band method allowing to generate over 50 years of realistic rain
fields.
Several questions are tackled in this study:
In a Thiessen estimation, how many rain gauges should be selected ? Which
weighting scheme should be used ?
SPAZM is an interpolator designed to produce unbiased mean annual
precipitation (MAP) at a catchment’s scale. So if a Thiessen areal rainfall is
scaled to fit the MAP given by SPAZM, how does it affect its extreme rainfall
estimation ?
If a virtual rain gauges network is extracted from the rain fields generated by
SAMPO, how do behave the Thiessen and SPAZM areal rainfall estimations
based on these point values ?
At the end, some abatement functions are obtained, showing the influence of the
catchment’s area and the options chosen to build the areal rainfall estimations.
References:
F. Gottardi, C. Obled, J. Gailhard, and E. Paquet, Statistical reanalysis of precipitation fields
based on ground network data and weather patterns : Application over french mountains.
Journal of Hydrology, 432-433:154 – 167, 2012. ISSN 0022-1694.
E. Leblois and J-D. Creutin, Space-time simulation of intermittent rainfall with prescribed
advection field: Adaptation of the turning band method. Water Resources Research,
49(6):3375-3387, 2013. ISSN 1944-7973. |
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