2 Advances in characterizing groundwater, surface water, and their interactions

This session focuses on characterizing groundwater, surface water, and their interactions through fieldwork, modeling, and data synthesis. We welcome submissions addressing flow, transport, water quality, and water levels under both typical and extreme conditions.

Sunday, 22 March 2026
8:00 AM - 12:00 PM
CCC, Room 25

Effects of timber management techniques on shallow groundwater and surface water temperatures in a deciduous Appalachian Forest

Paper number: 2-8
Program: Technical Sessions
Time: 10:20 AM – 10:40 AM

Authors

Abstract

Timber removal in forests can result in increases in surface water temperatures, especially in small watersheds. The associated removal of canopy cover increases the amount of solar radiation reaching streams, raising water temperature. However, this same canopy cover removal promotes the rapid growth of shrubs and mid-level canopy cover. While the removal of larger trees results in more immediate runoff, the growth of shrubs results in increased uptake of soil moisture stores and shallow groundwater. Combined, these processes can affect changes in groundwater temperatures. The complex interactions between timber management and surface and groundwater temperatures have rarely been described in the eastern United States. At the Fernow Experimental Forest in Parsons, WV, small watersheds have undergone ~67 years of timber management for research purposes. Techniques used include diameter-limited cuts, patch clear-cuts, and selection harvests. Regular measurement of surface water temperature in these streams has been intermittent throughout the 67-year history but has been most regular in the last ~25 years. Shallow groundwater depths and temperatures have only been recorded for the last two years in four locations. A cosine model has been applied to air, water, and groundwater temperatures in six watersheds in the Fernow. Mean temperature, amplitude, and phase of the cosine curve were determined for each watershed model. These parameters were compared to determine if significantly different temperature behavior can be observed among the watersheds. All temperature data had significant cosine behavior (p < 0.05), consistent with diurnal and seasonal air temperature values. Preliminary analyses of modeled data show there was no significant difference in model mean temperatures across any of the watersheds. Both surface water and groundwater temperature had amplitude dampening <1 compared to air, indicating that both surface water and groundwater are regularly cooler than air temperature. Surface water and groundwater temperatures also showed an increasing phase lag from air temperature, averaging 12.2 days and 51.2 days respectively, to reach maximum temperature after maximum air temperature. Maximum amplitude dampening occurred in shallow groundwater at higher elevations and total groundwater amplitude dampening averaged 0.40. This preliminary comparison shows that seasonal air temperature changes remain the major factor controlling surface water and groundwater temperature but localized differences in watersheds may due to differences in vegetative cover and underlying geology.

Geological Society of America Abstracts with Programs. Vol. 58, No. 2

doi: 10.1130/abs/2026NE-411305

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