U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights


Representing Floodplain Inundation in an Earth System Model
Published: March 23, 2017
Posted: January 26, 2018

Researchers use a macroscale inundation formulation to improve modeling of terrestrial surface hydrology in the Amazon basin.

The Science
Extreme events such as river inundation have extraordinary effects on terrestrial hydrology and aquatic ecosystems, but surface hydrology in basins with evident inundation can present modeling challenges. A research team led by scientists at the U.S. Department of Energy’s Pacific Northwest National Laboratory implemented a method to represent floodplain inundation in a river transport model.

The Impact
Researchers extended the Model for Scale Adaptive River Transport (MOSART), a key component of the DOE Accelerated Climate Modeling for Energy (ACME) earth system model, to include a macroscale inundation parameterization (formulation) for representing floodplain inundation. The extended model demonstrated improvement in modeling terrestrial surface hydrology in the Amazon River basin, where seasonal floods occur every year, with large impacts on the regional water and biogeochemical cycles. By representing floodplain inundation and refining geomorphological parameters and the river flow representation, researchers improved modeling of streamflow and inundation extent, which provides a foundation for predicting the impacts of global change on water resources and flood hazards in earth system models.

Summary
In this research, scientists implemented a macroscale inundation parameterization and integrated it with the MOSART surface-water transport model. When rivers overflowed their banks, the inundation parameterization estimated the amount of the river-floodplain water exchange, as well as the flooded area within each grid cell or watershed. Researchers applied the model to the Amazon basin, where floodplain inundation is a key component of surface water dynamics and plays an important role in water, energy, and carbon cycles. Scientists addressed four aspects of the challenges in continental-scale modeling of surface hydrology by (1) reducing the vegetation-induced biases (offsets from observations) in the digital elevation model data; (2) improving the approach for estimating channel cross-sectional geometry to better represent the spatial variability in channel geometry; (3) accounting for how riverbed resistance to river ?ow varies with the river size; and (4) considering the backwater effects to improve simulation of river flow in gentle-slope reaches. Researchers evaluated the model performance by using in situ streamflow records and satellite data of water level and inundation area. A sensitivity study showed that representing floodplain inundation, as well as refining floodplain topography, channel geometry and river flow representation, could significantly improve modeling of surface hydrology in the Amazon basin.

Contacts (BER PM)
Dorothy Koch
Earth System Modeling Program
Dorothy.Koch@science.doe.gov

(PI Contact)

L. Ruby Leung
Pacific Northwest National Laboratory
Ruby.Leung@pnnl.gov

Funding
The U.S. Department of Energy Office of Science, Biological and Environmental Research supported this research as part of the Accelerated Climate Modeling for Energy (ACME) project of the Earth System Modeling (ESM) program.

Publication
Luo, X., H-Y Li, L.R. Leung, T.K. Tesfa, A. Getirana, F. Papa, L.L. Hess, “Modeling Surface Water Dynamics in the Amazon Basin Using MOSART-Inundation v1.0: Impacts of Geomorphological Parameters and River Flow Representation.” Geoscientific Model Development 10, 1233-1259 (2017). [DOI: 10.5194/gmd-10-1233-2017]
(Reference link)

Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling

Division: SC-23.1 Climate and Environmental Sciences Division, BER

 

BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Aug 24, 2019
New Approach for Studying How Microbes Influence Their Environment
A diverse group of scientists suggests a common framework and targeting of known microbial processes [more...]

Aug 08, 2019
Nutrient-Hungry Peatland Microbes Reduce Carbon Loss Under Warmer Conditions
Enzyme production in peatlands reduces carbon lost to respiration under future high temperatures. [more...]

Aug 05, 2019
Amazon Forest Response to CO2 Fertilization Dependent on Plant Phosphorus Acquisition
AmazonFACE Model Intercomparison. The Science Plant growth is dependent on the availabi [more...]

Jul 29, 2019
A Slippery Slope: Soil Carbon Destabilization
Carbon gain or loss depends on the balance between competing biological, chemical, and physical reac [more...]

Jul 15, 2019
Field Evaluation of Gas Analyzers for Measuring Ecosystem Fluxes
How gas analyzer type and correction method impact measured fluxes. The Science A side- [more...]

List all highlights (possible long download time)