Preprints
https://doi.org/10.5194/gmd-2021-313
https://doi.org/10.5194/gmd-2021-313

Submitted as: development and technical paper 05 Oct 2021

Submitted as: development and technical paper | 05 Oct 2021

Review status: this preprint is currently under review for the journal GMD.

Modeling of streamflow in a 30-kilometer-long reach spanning 5 years using OpenFOAM 5.x

Yunxiang Chen, Jie Bao, Yilin Fang, William A. Perkins, Huiying Ren, Xuehang Song, Zhuoran Duan, Zhangshuan Hou, Xiaoliang He, and Timothy D. Scheibe Yunxiang Chen et al.
  • Pacific Northwest National Laboratory, Richland, Washington, USA 99354

Abstract. Developing accurate and efficient modeling techniques for streamflow at tens-kilometer spatial scale and multi-year temporal scale is critical for evaluating and predicting the impact of climate- and human-induced discharge variations on river hydrodynamics. However, achieving such a goal is challenging because of limited surveys of streambed hydraulic roughness, uncertain boundary condition specifications, and high computational costs. We demonstrate that accurate and efficient three-dimensional (3D) hydrodynamic modeling of natural rivers at 30-kilometer and 5-year scales is feasible using the following three techniques within OpenFOAM, an open source computational fluid dynamics platform: 1) generating a distributed hydraulic roughness field for the streambed by integrating water stage observation data, a rough wall theory, and a local roughness optimization and adjustment strategy; 2) prescribing the boundary condition for the inflow and outflow by integrating pre-computed results of a one-dimensional (1D) hydraulic model with the 3D model; and 3) reducing computational time using multiple parallel runs constrained by 1D inflow and outflow boundary conditions. Streamflow modeling for a 30-kilometer-long reach in the Columbia River (CR) over 58 months can be achieved in less than six days using 1.1 million CPU hours. The mean error between the modeled and the observed water stages for our simulated CR reach ranges from −16 cm to 9 cm (equivalent to ca. ±7 % relative to the average water depth) at seven locations during most of the years between 2011 and 2019. We can reproduce the velocity distribution measured by the acoustic Doppler current profiler (ADCP). The correlation coefficients of the depth-averaged velocity between the model and ADCP measurements are in the range between 0.71 and 0.83 at 75 % of the survey cross-sections. With the validated model, we further show that the relative importance of dynamic pressure versus hydrostatic pressure varies with discharge variations and topography heterogeneity. Given the model's high accuracy and computational efficiency, the model framework provides a generic approach to evaluate and predict the impact of climate- and human-induced discharge variations on river hydrodynamics at tens kilometer and decade scales.

Yunxiang Chen et al.

Status: open (until 30 Nov 2021)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse

Yunxiang Chen et al.

Data sets

Model, data, and code for paper "Modeling of streamflow in a 30-kilometer-long reach spanning 5 years using OpenFOAM 5.x" Chen, Y.; Bao, J.; Fang, Y.; Perkings, W. A.; Ren, H.; Song, X.; Duan, Z.; Hou, Z.; He, X.; Scheibe, T. D. https://doi.org/10.15485/1819956

Yunxiang Chen et al.

Viewed

Total article views: 229 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
176 46 7 229 3 4
  • HTML: 176
  • PDF: 46
  • XML: 7
  • Total: 229
  • BibTeX: 3
  • EndNote: 4
Views and downloads (calculated since 05 Oct 2021)
Cumulative views and downloads (calculated since 05 Oct 2021)

Viewed (geographical distribution)

Total article views: 208 (including HTML, PDF, and XML) Thereof 208 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 22 Oct 2021
Download
Short summary
Climate change affects river discharge variations that alter streamflow. By integrating multi-type survey data with a computational fluid dynamics tool, OpenFOAM, we show a workflow that enables accurate and efficient streamflow modeling at 30-km and 5-year scales. The model accuracy for water stage and depth average velocity is −16 cm~9 cm and 0.71~0.83 in terms of mean error and correlation coefficients. This accuracy indicates the model’s reliability for evaluating climate’s impact on rivers.