Abstract
The hillslope and channel dynamics that govern streamflow permanence in headwater systems have important implications for ecosystem functioning and downstream water quality. Recent advancements in process-based, semi-distributed hydrologic models that build upon empirical studies of streamflow permanence in well-monitored headwater catchments show promise for characterizing the dynamics of streamflow permanence in headwater systems. However, few process-based models consider the continuum of hillslope-stream network connectivity as a control on streamflow permanence in headwater systems. The objective of this study was to expand a process-based, catchment-scale hydrologic model to better understand the spatiotemporal dynamics of headwater streamflow permanence and to identify controls of streamflow expansion and contraction in a headwater network. Further, we aimed to develop an approach that enhanced the fidelity of model simulations, yet required little additional data, with the intent that the model might be later transferred to catchments with limited long-term and spatially explicit measurements. This approach facilitated network-scale estimates of the controls of streamflow expansion and contraction, albeit with higher degrees of uncertainty in individual reaches due to data constraints. Our model simulated that streamflow permanence was highly dynamic in first-order reaches with steep slopes and variable contributing areas. The simulated stream network length ranged from nearly 98±2% of the geomorphic channel extent during wet periods to nearly 50±10% during dry periods. The model identified a discharge threshold of approximately 1 mm d−1, above which the rate of streamflow expansion decreases by nearly an order of magnitude, indicating a lack of sensitivity of streamflow expansion to hydrologic forcing during high-flow periods. Overall, we demonstrate that process-based, catchment-scale models offer important insights on the controls of streamflow permanence, despite uncertainties and limitations of the model. We encourage researchers to increase data collection efforts and develop benchmarks to better evaluate such models.
| Original language | English |
|---|---|
| Article number | 129422 |
| Journal | Journal of Hydrology |
| Volume | 620 |
| DOIs | |
| State | Published - May 2023 |
Bibliographical note
Funding Information:This paper has been reviewed in accordance with the U.S. Environmental Protection Agency's peer and administrative review policies and approved for publication. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Statements in this publication reflect the authors' professional views and opinions and should not be construed to represent any determination or policy of the U.S. Environmental Protection Agency (USEPA). This paper has been peer reviewed and approved for publication consistent with USGS Fundamental Science Practices (https://pubs.usgs.gov/circ/1367/). This project was supported in part by an appointment to the Research Participation Program at the Office of Research and Development, USEPA, administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the U.S. Department of Energy and USEPA. We appreciate helpful suggestions from two internal reviewers at the USEPA as well as a colleague reviewer at USGS. We also thank Gianluca Botter and an anonymous reviewer for comments that helped us greatly improve the quality of this work.
Funding Information:
This paper has been reviewed in accordance with the U.S. Environmental Protection Agency's peer and administrative review policies and approved for publication. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Statements in this publication reflect the authors' professional views and opinions and should not be construed to represent any determination or policy of the U.S. Environmental Protection Agency (USEPA). This paper has been peer reviewed and approved for publication consistent with USGS Fundamental Science Practices (https://pubs.usgs.gov/circ/1367/). This project was supported in part by an appointment to the Research Participation Program at the Office of Research and Development, USEPA, administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the U.S. Department of Energy and USEPA. We appreciate helpful suggestions from two internal reviewers at the USEPA as well as a colleague reviewer at USGS. We also thank Gianluca Botter and an anonymous reviewer for comments that helped us greatly improve the quality of this work.
Publisher Copyright:
© 2023 Elsevier B.V.
Keywords
- Expansion and contraction
- Hydrologic connectivity
- Modeling
- Streamflow permanence
ASJC Scopus subject areas
- Water Science and Technology