11 Future Voices in Geoscience- Undergraduate Research Posters

This session is for two-year college and four-year college and university students presenting research posters in any subdiscipline of geosciences. Posters and presentations will be judged for awards.

Monday, 18 May 2026
8:00 AM - 5:30 PM
Alvarado D/E

Flood Duration Controls Geomorphic Response to Extreme Flooding in Northeastern Yellowstone National Park

Paper number: 11-4
Program: Technical Sessions
Time: 8:00 AM – 8:00 AM

Authors

Abstract

River reaches in northeastern Yellowstone National Park provide an opportunity to evaluate the geomorphic effects of extreme floods. This study focuses on determining the source of sediment deposited in channels and the role of flood duration on sediment transport on two mountainous alluvial reaches that drain the Beartooth Uplift. Both Pebble and Slough Creeks experienced substantial geomorphic change during the extreme, AEP <0.2%, flood in 2022, however the style of channel deposition and sources of sediment were different. On Slough Creek, the 2022 event had an estimated peak discharge of 587 m3s-1 with 1 day above flood stage, and another extreme event occurred in 1918 with an estimated peak discharge of 259 m3s-1 with 11 days above flood stage. During the 2022 event, sediment movement in Pebble Creek was largely driven by sediment sourced from the alluvial fan at its confluence with Soda Butte Creek, whereas sediment movement in Slough Creek was primarily supplied by a late Pinedale moraine that crosses the valley axis. Using field observations of post-flood channel change, a DEM of difference created from pre- and post-flood LiDAR datasets, two-dimensional hydraulic modeling, and one-dimensional sediment transport modeling, we assess where the greatest amounts of erosion and deposition occurred on Slough Creek. Two sediment transport modeling scenarios explore the sensitivity of sediment transport and geomorphic response to flood magnitude and duration, allowing comparison between the 2022 and 1918 events. Flood duration exerts an important control on the extent of geomorphic work, influencing both the amount of sediment mobilized and the distance it was transported within a channel reach. Our models show that on Slough Creek, the 2022 flood moved 7,098 m3 of sediment out of the reach, while the 1918 event moved 23,410 m3 out of the reach, indicating substantially greater geomorphic effectiveness during the longer duration flood.

Geological Society of America Abstracts with Programs. Vol. 58, No. 4

doi: 10.1130/abs/2026RM-410585

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