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Abstract This study integrated spatially distributed field observations and soil thermal models to constrain the impact of frozen ground on snowmelt partitioning and streamflow generation in an alpine catchment within the Niwot Ridge Long‐Term Ecological Research site, Colorado, USA. The study area was comprised of two contrasting hillslopes with notable differences in topography, snow depth and plant community composition. Time‐lapse electrical resistivity surveys and soil thermal models enabled extension of discrete soil moisture and temperature measurements to incorporate landscape variability at scales and depths not possible with point measurements alone. Specifically, heterogenous snowpack thickness (~0–4 m) and soil volumetric water content between hillslopes (~0.1–0.45) strongly influenced the depths of seasonal frost, and the antecedent soil moisture available to form pore ice prior to freezing. Variable frost depths and antecedent soil moisture conditions were expected to create a patchwork of differing snowmelt infiltration rates and flowpaths. However, spikes in soil temperature and volumetric water content, as well as decreases in subsurface electrical resistivity revealed snowmelt infiltration across both hillslopes that coincided with initial decreases in snow water equivalent and early increases in streamflow. Soil temperature, soil moisture and electrical resistivity data from both wet and dry hillslopes showed that initial increases in streamflow occurred prior to deep soil water flux. Temporal lags between snowmelt infiltration and deeper percolation suggested that the lateral movement of water through the unsaturated zone was an important driver of early streamflow generation. These findings provide the type of process‐based information needed to bridge gaps in scale and populate physically based cryohydrologic models to investigate subsurface hydrology and biogeochemical transport in soils that freeze seasonally.
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This content will become publicly available on February 27, 2026
Laboratory Investigations into the Effects of Heating on Clay’s Mechanical and Hydraulic Changes Using Geophysical Methods
This research explores the responses of reconstituted Kaolin clay samples due to simulations of wildfires in the laboratory using heat guns for control heating. Two laboratory geophysical methods, bender element and electrical resistivity, were used to detect the changes in soil’s mechanical (shear modulus, Gmax) and hydraulic properties (electrical resistivity, ρ) in real time, while soil specimens were heated, up to 60°C, to partially represent the temperatures in a wildfire. Measurements were compared with samples that had not been heated. Results show that the Gmax values for the controlled samples were about 25% greater than those that were heated, which implied that heating causes soil strength reduction. Additionally, the electrical resistivity for the controlled samples was 55% higher than that of the heated samples, meaning that heating caused the kaolin specimens to be less permeable. Correlations between Gmax versus temperature (T) and water content were developed. Results also allowed for the development of electrical resistivity, temperature, and water content correlations.
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- Award ID(s):
- 2112554
- PAR ID:
- 10610201
- Publisher / Repository:
- American Society of Civil Engineers
- Date Published:
- ISBN:
- 9780784485705
- Page Range / eLocation ID:
- 47 to 56
- Format(s):
- Medium: X
- Location:
- Louisville, Kentucky
- Sponsoring Org:
- National Science Foundation
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