Abstract
The hydrological and biogeochemical properties of the hyporheic zone in stream and riverine ecosystems have been extensively studied over the past two decades. Although it is widely acknowledged that sediment heterogeneity can influence biogeochemical reactions, little effort has been made to understand the role of heterogeneity on the spatiotemporal variability of riverbed redox conditions under changing flow dynamics at different timescales. Here we integrate a mechanistic model and field data to demonstrate that heterogeneity in permeability plays a vital role in modulating sediment redox conditions at both seasonal (annual) and event (daily-to-weekly) timescales, whereas heterogeneity in particulate organic carbon (POC) content only has a comparable influence on redox conditions at the seasonal timescale. These findings underscore the importance of accurately characterizing sediment heterogeneity, in terms of permeability and POC content, in quantifying biogeochemical dynamics in the riverbed and hyporheic zones of riverine ecosystems.
| Original language | English |
|---|---|
| Article number | e2023GL107761 |
| Journal | Geophysical Research Letters |
| Volume | 51 |
| Issue number | 11 |
| DOIs | |
| State | Published - Jun 16 2024 |
| Externally published | Yes |
Funding
We thank Audrey H. Sawyer from Ohio State University for providing constructive comments on the model settings. This study was supported by National Natural Science Foundation of China (No. 42141003, No. 41931292, No. 42207062), National Key R&D program of China (No. 2021YFC3200500, No. 2021YFC3200502), Guangdong Provincial Basic and Applied Basic Research Fund (No. 2021A1515110781), and Shenzhen Science and Technology Innovation Committee (JCYJ20210324105009024). The computational resources for the model calculations were supported by Center for Computational Science and Engineering at Southern University of Science and Technology. This research was also supported by the U.S. Department of Energy, Office of Biological and Environmental Research, Environmental System Science (ESS) program through Grants DE-SC0016217 and DE-SC0020309. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government. We thank Audrey H. Sawyer from Ohio State University for providing constructive comments on the model settings. This study was supported by National Natural Science Foundation of China (No. 42141003, No. 41931292, No. 42207062), National Key R&D program of China (No. 2021YFC3200500, No. 2021YFC3200502), Guangdong Provincial Basic and Applied Basic Research Fund (No. 2021A1515110781), and Shenzhen Science and Technology Innovation Committee (JCYJ20210324105009024). The computational resources for the model calculations were supported by Center for Computational Science and Engineering at Southern University of Science and Technology. This research was also supported by the U.S. Department of Energy, Office of Biological and Environmental Research, Environmental System Science (ESS) program through Grants DE‐SC0016217 and DE‐SC0020309. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government.
Keywords
- heterogeneity
- hydrologic exchange flow
- hyporheic zone
- reactive transport
- sediment redox condition