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| Titel |
Simulation of absolute water surface elevations in a global river model: a case study in the Amazon River |
| VerfasserIn |
Dai Yamazaki, Hyongki Lee, Doug Alsdorf, Emanuel Dutra, Hyungjun Kim, Shinjiro Kanae, Taikan Oki, Paul Bates |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250074388
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| Zusammenfassung |
| Water level dynamics in continental-scale rivers is an important factor for surface water
studies and flood hazard management. However, most continental-scale river models have not focused on the
reproduction of water level because the storage and movement of surface waters are regulated by smaller
scale topography than their grid resolutions. Here we analyzed the water level dynamics simulated by a state-
of-the-art global river model, CaMa-Flood, with sub-grid representation of floodplain topography. As a case
study, hydrodynamics simulation in the Amazon River was accomplished, and the simulated water surface
elevations along the mainstem were compared against Envisat altimetry. The seasonal cycle of the simulated
water surface elevations are in agreement with the altimetry (correlation coefficient >0.69, annual amplitude
error <1.6 m). The accuracy of absolute water surface elevations was also good (averaged RMSE of 1.83 m),
and the associated errors were within the range of the model uncertainty due to channel cross-section
parameters. Then, the ocean tide variation at river mouth was incorporated for simulating the tidal effect in the
inland Amazon basin, which requires realistic representation of absolute water surface elevations. By applying
power-spectra analysis to the simulated water level variations, the 15-day cycle due to spring and neap tides
was detected at Obidos located 800 km upstream from the river mouth. The reproduction of the ocean tide
propagation to the inland region suggests that CaMa-Flood includes the main physical processes needed to
accurately simulate the water level dynamics in continental-scale rivers. |
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