BER launches Environmental System Science Program. Visit our new website under construction!

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

BER Research Highlights

New Model Enables Scientists to Predict Hydrologic Exchange Fluxes at River Reach Scale
Published: April 10, 2019
Posted: August 10, 2020

10 April 2019

Fluid dynamics modeling along a 7-kilometer river reach reveals factors controlling large-scale hydrologic exchange fluxes. 

The Science
Hydrologic exchange fluxes (HEFs) between rivers and surrounding subsurface environments strongly influence water temperatures and biogeochemical processes. Yet, quantitative measures of their effects on the strength and direction of such exchanges in large rivers are lacking. A study reported in Hydrological Processes, led by scientists at Pacific Northwest National Laboratory (PNNL), demonstrates the efficacy of a new coupled surface and subsurface fluid dynamics model in quantifying HEFs at kilometer scales. 

The Impact
In a world where dam-regulated river corridors are increasingly common, quantifying HEFs and their effects at river-reach scales is vitally important in protecting water quality and ecosystem health. Through three-dimensional (3D) application of computational fluid dynamics (CFD) modeling, combined with uncertainty quantification tools, the new model can quantify HEFs in a large-scale river channel extending 1 km wide and 7 km long. This a dramatic improvement over traditional simulations, which (at most) model just a few hundred meters of river corridor. 

HEFs are critical to shaping hydrological and biogeochemical processes along river corridors. Yet, in current research, numerical modeling studies to quantify riverine HEFs are typically confined to local-scale simulations in which the river is a few meters wide and up to a just few hundred meters long. Even then, such studies are challenging because of high computational demands and the complexity of riverine geomorphology and subsurface geology. In addition, there are limitations in field accessibility, and the physical demands of labor-intensive data collection along river shorelines. 

A new model, developed by a multi-institutional team, addresses these challenges. Their recently published paper in Hydrological Processes demonstrates a new coupled surface and subsurface water flow model that can be applied at large scales. 

The new model was validated against field-scale observations—including velocity measurements from an acoustic Doppler current profiler, a set of temperature profilers installed across the riverbed to measure vertical HEFs, and simulations from PFLOTRAN (a reactive transport model). Then, along a 7-km segment of the Columbia River that experiences high dam-regulated flow variations, the model was used to systematically investigate how HEFs could be influenced by surface water fluid dynamics, subsurface structures, and hydrogeological properties. 

The simulations demonstrated that reach-scale HEFs are dominated by the thickness of the riverbed alluvium layer, followed by alluvium permeability, the depth of the underlying impermeable layer, and the pressure boundary condition. 

These results are being used to guide the design and placement of new field sensor systems that will further enhance scientific understanding of HEFs in large dam-regulated rivers.

BER Program Manager
Paul Bayer
U.S. Department of Energy Office of Biological and Environmental Research 

Principal Investigator
Jie Bao
Pacific Northwest National Laboratory 

Funding was provided by the Office of Biological and Environmental Research (BER), within the U.S. Department of Energy (DOE), as part of the BER’s Subsurface Biogeochemistry Research (SBR) program.  This research is part of the SBR Scientific Focus Area project at PNNL.

Bao, J., T. Zhou, M. Huang, Z. Hou, W. Perkins, et al. “Modulating factors of hydrologic exchanges in a large-scale river reach: Insights from three-dimensional computational fluid dynamics simulations.” Hydrological Processes 32(23), 3446–63 (2018). [DOI:10.1002/hyp.13266].

Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling
  • Research Area: Subsurface Biogeochemical Research

Division: SC-33.1 Earth 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

Jan 11, 2022
No Honor Among Copper Thieves
Findings provide a novel means to manipulate methanotrophs for a variety of environmental and in [more...]

Dec 06, 2021
New Genome Editing Tools Can Edit Within Microbial Communities
Two new technologies allow scientists to edit specific species and genes within complex laborato [more...]

Oct 27, 2021
Fungal Recyclers: Fungi Reuse Fire-Altered Organic Matter
Degrading pyrogenic (fire-affected) organic matter is an important ecosystem function of fungi i [more...]

Oct 19, 2021
Microbes Offer a Glimpse into the Future of Climate Change
Scientists identify key features in microbes that predict how warming affects carbon dioxide emi [more...]

Aug 25, 2021
Assessing the Production Cost and Carbon Footprint of a Promising Aviation Biofuel
Biomass-derived DMCO has the potential to serve as a low-carbon, high-performance jet fuel blend [more...]

List all highlights (possible long download time)