Controls From Above and Below: Snow, Soil, and Steepness Drive Diverging Trends of Subsurface Water and Streamflow Dynamics

Journal Article · Tue Apr 01 00:00:00 EDT 2025 · Hydrological Processes

DOI:https://doi.org/10.1002/hyp.70120· OSTI ID:2549489

Kerins, Devon ^[1]; Knapp, Abigail S. ^[1]; Liu, Fiona S. ^[1]; Smykalov, Valerie Diana ^[1]; Berzonsky, Matthew P. ^[1]; Vierbicher, Andrew ^[1]; Sadayappan, Kayalvizhi ^[1]; Stewart, Bryn ^[1]; Andrews, Elizabeth M. ^[2]; Sullivan, Pamela L. ^[3]; Barnard, Holly R. ^[4]; Seibert, Jan ^[5]; McPhillips, Lauren E. ^[1]; Singha, Kamini ^[6]; Li, Li ^[1]

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1. Department of Civil and Environmental Engineering The Pennsylvania State University University Park PA USA
2. Department of Earth, Environmental and Resources Sciences University of Texas at El Paso El Paso TX USA
3. College of Earth, Ocean, and Atmospheric Sciences, Oregon State University Corvallis OR USA
4. Department of Geography Institute of Arctic and Alpine Research, University of Colorado Boulder CO USA
5. Department of Geography University of Zurich Zurich Switzerland
6. Hydrologic Science and Engineering Program Colorado School of Mines Golden CO USA

ABSTRACT

The importance of subsurface water dynamics, such as water storage and flow partitioning, is well recognised. Yet, our understanding of their drivers and links to streamflow generation has remained elusive, especially in small headwater streams that are often data‐limited but crucial for downstream water quantity and quality. Large‐scale analyses have focused on streamflow characteristics across rivers with varying drainage areas, often overlooking the subsurface water dynamics that shape streamflow behaviour. Here we ask the question: What are the climate and landscape characteristics that regulate subsurface dynamic storage, flow path partitioning, and dynamics of streamflow generation in headwater streams? To answer this question, we used streamflow data and a widely‐used hydrological model (HBV) for 15 headwater catchments across the contiguous United States. Results show that climate characteristics such as aridity and precipitation phase (snow or rain) and land attributes such as topography and soil texture are key drivers of streamflow generation dynamics. In particular, steeper slopes generally promoted more streamflow, regardless of aridity. Streams in flat, rainy sites (< 30% precipitation as snow) with finer soils exhibited flashier regimes than those in snowy sites (> 30% precipitation as snow) or sites with coarse soils and deeper flow paths. In snowy sites, less weathered, thinner soils promoted shallower flow paths such that discharge was more sensitive to changes in storage, but snow dampened streamflow flashiness overall. Results here indicate that land characteristics such as steepness and soil texture modify subsurface water storage and shallow and deep flow partitioning, ultimately regulating streamflow response to climate forcing. As climate change increases uncertainty in water availability, understanding the interacting climate and landscape features that regulate streamflow will be essential to predict hydrological shifts in headwater catchments and improve water resources management.

• Sponsoring Organization: USDOE
• OSTI ID: 2549489
• Journal Information: Hydrological Processes, Journal Name: Hydrological Processes Journal Issue: 4 Vol. 39; ISSN 0885-6087
• Publisher: Wiley Blackwell (John Wiley & Sons)
• Country of Publication: United Kingdom
• Language: English