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| Titel |
Assessment of morphological parameters in altimetry-based rating curves |
| VerfasserIn |
Adrien Paris, Pierre André Garambois, Stéphane Calmant, Walter Collischonn, Joecila Santos da Silva, Daniel Medeiro Moreira, Marie-Paule Bonnet, Frédérique Seyler |
| 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 |
250108903
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| Publikation (Nr.) |
 EGU/EGU2015-8739.pdf |
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| Zusammenfassung |
| A set of altimetry-based rating curves have been obtained by polynomial fit of ENVISAT
water stages and discharges obtained from MGB-IPH model, with constraints on parameters
values. The rated discharges, e.g. the discharge obtained from ENVISAT heights through the
rating curves were successfully validated towards simulated discharges (meanEns = 0,70)
and in-situ discharges (meanEns = 0,71). Results also showed that rating curves are not
mission-dependent, as we were able to obtain accurate discharge estimates from Jason-2
stages through a RC calculated from ENVISAT time series. In addition, RC parameters have
proven to provide reliable information of river’s morphological parameters, as water depths
for example.
The water depth can be inferred at any date with stage information by subtracting to it the
parameter (Z0 is such as Q = 0 when Halti = Z0) from the RC. The result of this operation
was tested towards measured water depths from ADCP obtained during ground missions.
ADCP water depth is inferred by dividing cross-section area by width. We obtained great
results at the seven sites tested, with error in depth estimate always inferior to 10% of the
river depth. The Z0 parameter also was validated through inverse modeling. Using the
effective bathymetry given by a series of Z0 values along a river reach, a hydraulic
model (with simple hypothesis like permanent shallow water flow for each satellite
pass and continuous roughness for a continuous discharge) was able to return free
surface elevations and slopes similar to observed ENVISAT water elevations. These
experiments show that altimetry-based rating curves provide effective estimates of
morphological parameters of river reaches that can be used as inputs into hydraulic models. |
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