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Dynamics of streamflow permanence in a headwater network: Insights from catchment-scale model simulations
D T Mahoney1, J R Christensen2, H E Golden2
1Department of Civil and Environmental Engineering, University of Louisville, Louisville, KY.
Journal of Hydrology
|August 30, 2024
Summary
Streamflow permanence in headwater systems is dynamic, influenced by hillslope and channel processes. Our enhanced model reveals controls on streamflow expansion and contraction, crucial for water quality and ecosystem health.
Area of Science:
- Hydrology
- Geomorphology
- Environmental Science
Background:
- Streamflow permanence in headwater systems is vital for ecosystem function and water quality.
- Existing hydrologic models often overlook hillslope-stream connectivity's role in streamflow dynamics.
- Process-based models show promise but require refinement for accurate streamflow permanence characterization.
Purpose of the Study:
- To expand a process-based model to simulate headwater streamflow permanence dynamics.
- To identify controls on streamflow expansion and contraction within headwater networks.
- To develop a data-efficient modeling approach for broader application.
Main Methods:
- Developed and applied a catchment-scale, process-based hydrologic model.
- Focused on hillslope-stream network connectivity.
- Simulated spatiotemporal dynamics of streamflow permanence.
Main Results:
- Streamflow permanence was highly dynamic in steep, first-order reaches.
- Simulated stream network extent varied from 98% (wet) to 50% (dry) of the geomorphic channel.
- Identified a discharge threshold (1 mm d-1) above which expansion sensitivity decreases significantly.
Conclusions:
- Process-based models provide valuable insights into streamflow permanence controls.
- Model simulations highlight the dynamic nature of headwater stream networks.
- Further data collection and model benchmarking are recommended for improved accuracy.
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