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Modeling Surface Water Dynamics in the Amazon Basin Using Mosart-Inundation-v1.0: Impacts of Geomorphological Parameters and River Flow RepresentationSurface water dynamics play an important role in water, energy and carbon cycles of the Amazon Basin. A macro-scale inundation scheme was integrated with a surface-water transport model and the extended model was applied in this vast basin. We addressed the challenges of improving basin-wide geomorphological parameters and river flow representation for 15 large-scale applications. Vegetation-caused biases embedded in the HydroSHEDS DEM data were alleviated by using a vegetation height map of about 1-km resolution and a land cover dataset of about 90-m resolution. The average elevation deduction from the DEM correction was about 13.2 m for the entire basin. Basin-wide empirical formulae for channel cross-sectional geometry were adjusted based on local information for the major portion of the basin, which could significantly reduce the cross-sectional area for the channels of some subregions. The Manning roughness coefficient of the channel 20 varied with the channel depth to reflect the general rule that the relative importance of riverbed resistance in river flow declined with the increase of river size. The entire basin was discretized into 5395 subbasins (with an average area of 1091.7 km2), which were used as computation units. The model was driven by runoff estimates of 14 years (1994 2007) generated by the ISBA land surface model. The simulated results were evaluated against in situ streamflow records, and remotely sensed Envisat altimetry data and GIEMS inundation data. The hydrographs were reproduced fairly well for the majority of 25 13 major stream gauges. For the 11 subbasins containing or close to 11 of the 13 gauges, the timing of river stage fluctuations was captured; for most of the 11 subbasins, the magnitude of river stage fluctuations was represented well. The inundation estimates were comparable to the GIEMS observations. Sensitivity analyses demonstrated that refining floodplain topography, channel morphology and Manning roughness coefficients, as well as accounting for backwater effects could evidently affect local and upstream inundation, which consequently affected flood waves and inundation of the downstream 30 area. It was also shown that the river stage was sensitive to local channel morphology and Manning roughness coefficients, as well as backwater effects. The understanding obtained in this study could be helpful to improving modeling of surface hydrology in basins with evident inundation, especially at regional or larger scales.
Document ID
20170003707
Document Type
Accepted Manuscript (Version with final changes)
Authors
Luo, Xiangyu
(Pacific Northwest National Lab. Richland, WA, United States)
Li, Hong-Yi
(Pacific Northwest National Lab. Richland, WA, United States)
Leung, Ruby
(Pacific Northwest National Lab. Richland, WA, United States)
Tesfa, Teklu K.
(Pacific Northwest National Lab. Richland, WA, United States)
Getirana, Augusto
(Maryland Univ. Greenbelt, MD, United States)
Papa, Fabrice
(Toulouse Univ. France)
Hess, Laura L.
(California Univ. Santa Barbara, CA, United States)
Date Acquired
April 20, 2017
Publication Date
March 23, 2017
Publication Information
Publication: Geoscientific Model Development
Volume: 10
Issue: 3
ISSN: 1991-959X
Subject Category
Earth Resources And Remote Sensing
Report/Patent Number
GSFC-E-DAA-TN41655
Funding Number(s)
CONTRACT_GRANT: NNX17AE79A
CONTRACT_GRANT: DE-AC05-76RLO1830
Distribution Limits
Public
Copyright
Public Use Permitted.
Keywords
geomorphological
fluctuations

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