From Grains to Plastics: Modeling Nourishment Patterns and Hydraulic Sorting of Fluvially Transported Materials in Deltas
Abstract
Understanding the way fluvially transported materials are partitioned in river deltas is essential for predicting their morphological change and the fate of environmental constituents and contaminants. Translating water-based partitioning estimates into fluxes of nonwater materials is often difficult to constrain because most materials are not uniformly distributed in the water column and may have characteristic transport pathways that differ from the mean flow. Here, we present a novel reduced-complexity modeling approach for simulating the patterns of transport of a diverse range of suspended fluvial inputs influenced by vertical stratification and topographic steering. We utilize a mixed Eulerian-Lagrangian modeling approach to estimate the patterns of nourishment and connectivity in the Wax Lake and Atchafalaya Deltas in coastal Louisiana. Using the reduced-complexity particle routing model dorado, in conjunction with a calibrated ANUGA hydrodynamic model, we quantify how transport patterns in each system change as a function of a material's Rouse number and environmental conditions. We find that even small changes to local topographic steering lead to emergent system-scale changes in patterns of fluvial nourishment, with greater channel-island connectivity for positively buoyant materials than negatively buoyant materials, hydraulically sorting different materials in space. We also find that the nourishment patterns of some materials are more sensitive than others to changes in discharge, tidal conditions, and anthropogenic dredging. Our results have important implications for understanding the eco-geomorphic evolution of deltas, and our modeling framework could have interdisciplinary implications for studying the transport of materials in other systems, including sediments, nutrients, wood, plastics, and biotic materials.
Additional Information
© 2022 The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. This work was supported primarily by the NASA Delta-X project, which is funded by the Science Mission Directorate's Earth Science Division through the Earth Venture Suborbital-3 Program NNH17ZDA001N-EVS3. We also acknowledge partial support by the National Science Foundation via NSF EAR-1719670. We thank the Texas Advanced Computing Center (TACC) at the University of Texas at Austin for providing HPC resources that have contributed to the research results reported within this paper. We thank David Mohrig, Ben Hodges, Andrew Moodie, Nelson Tull, and Marc Simard for helpful feedback on this work. We also thank the rest of the Delta-X research team. Finally, we thank Editor Ton Hoitink and Associate Editor Christophe Ancey for handling this manuscript, as well as Brad Murray and one anonymous reviewer for peer-reviewing this work. Data Availability Statement. All hydrodynamic outputs, dorado simulation results, and codes needed to reproduce this analysis are available for download at https://doi.org/10.5281/zenodo.7187585. Current links for the run-scripts of the ANUGA model of the Wax Lake and Atchafalaya Delta system can be found at deltax.jpl.nasa.gov and the final versions will be accessible via the ORNL DAAC. The particle-tracking model dorado is fully open-source and has been archived at https://doi.org/10.5281/zenodo.6454729, and the most up-to-date version can be found on GitHub at https://github.com/passaH2O/dorado.Attached Files
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Additional details
- Eprint ID
- 119857
- Resolver ID
- CaltechAUTHORS:20230307-206415500.31
- NNH17ZDA001N‐EVS3
- NASA
- EAR‐1719670
- NSF
- Created
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2023-05-18Created from EPrint's datestamp field
- Updated
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2023-05-19Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences