Research (old) | portfolio

I study rivers and the ways they transport sediment to understand flood hazard in the Pacific Northwest. I use data analysis, remote sensing and models to investigate how rivers are changing in shape and hydrologic regime.

PROJECTS

Modeling HydroGeomorphic Hazards (MoHGeoH)

2018-Present:

"How do the ways rivers transport sediment affect flooding?"

At the University of Washington, we are working on a mountain-to-coast flood prediction method that integrates sediment and river morphodynamics. As part of this effort, I am quantifying how long-term changes in river conveyance capacity affect flood risk in western Washington State.

This collaborative project is funded as part of the NSF PREEVENTS program: https://www.ce.washington.edu/news/article/2018-12-26/flood-and-landslide-risk-research-funded-nsf-grant

Rapid Groundwater Modeling: Method Development

2017-2018

"How can we improve rapid-aquifer level predictions by incorporating real-time data into physical models?"

In this project, I collaborated with the Illinois State Water Survey to apply a method for rapid groundwater modeling to an unconfined aquifer in Illinois. I established model proof-of-concept and developed a Python framework for using a MODFLOW groundwater model with real-time field data to solve for continuous aquifer levels.

Publication in Prep:
Abrams, D.B. and S. Ahrendt. “Applying a head-specified MODFLOW model of unconfined aquifer conditions to assess the impact of seasonally variable recharge and pumping”

IPython Instructional Notebooks

2017-2018

Teaching model development with visual support.

I developed and illustrated IPython notebooks for teaching MODFLOW groundwater modeling through python at the Illinois State Water Survey.

Notebooks available at: https://github.com/shelbyahrendt/flopy-tutorials

Hercules Dome, Digital Elevation Model

Summer 2016:

The goal of this project was to identify the optimal location for deep antarctic ice core drilling. In contribution, I created a Digital Elevation Model from CryoSat-2 radar altimetry data to be used in focusing ground-based surveying. The project was conducted at the St. Olaf Center for Geophysical Studies of Ice and Climate under the advice of Dr. Robert Jacobel. Funded by the St. Olaf College CURI undergraduate research program.

AGU Fall 2017 abstract: http://bit.ly/hercdome

PUBLICATIONS

Ahrendt, S., Blom A., Van Denderen, R. P., Schielen, R. M. J., Horner-Devine, A. R., (in review) Geometric floodplain controls on riverbed elevation change within and between flood events
Ahrendt, S., Horner-Devine, A. R., Collins, B., Morgan, J., Istanbulluoglu, E., (2022) Channel Conveyance variability can influence flood risk as much as streamflow variaibility in western Washington State, Water Resources Research. https://doi.org/10.1029/2021WR031890
Morgan, J. A., Kumar, N., Horner-Devine, A. R., Ahrendt, S., Istanbullouglu,
E., Bandargoda, C., (2020), Simulating large-scale and long-term fluvial morphodynamics: The efficacy of using a morphological acceleration factor. Geomorphology, 356, p. 107088, https://doi.org/10.1016/j.geomorph.2020.107088

SELECTED PRESENTATIONS

Ahrendt, S. (Presenter), Blom, A., VanDenderen, R. P., Schielen, R. M. J., Horner-Devine, A. R., "The influence of floodplain geometry on riverbed elevation change within and between floods." Poster Presentation at the Netherlands Centre for River Studies, NCR-Days Conference (April 2022) Delft, The Netherlands
Ahrendt, S. (Presenter), Horner-Devine, A., Kumar, N., Morgan, J. A., Collins, B., Istanbulluoglu, E. “Understanding Morphologic Flood Risk Relevant to River Management in Western Washington State” Oral Presentation at the American Geophysical Union Fall Meeting (Dec, 2020) Online

AGU 2020 Virtual Presentation

Ahrendt, S. (Presenter), Horner-Devine, Kumar, N., A., Morgan, J. A., Collins, B., Istanbulluoglu, E. “River Morphology and Flood Risk in the Pacific Northwest” Oral Presentation at the Community Surface Dynamics Modeling System: Summer Science Series (July, 2020) Online

CSDMS Summer Series 2020, Virtual Presentation

Ahrendt, S., (Presenter) A. Horner-Devine, N. Kumar, J. Morgan, B. Collins, E. Istanbulluoglu, C. Bandargoda, A. Pfeiffer, "How is channel capacity connected to flood risk in high sediment supply mountain basins?" Oral presentation at the American Geophysical Union Fall Conference (Dec, 2019) San Francisco, CA
Ahrendt, S., (Presenter) Morgan, J. A., Horner-Devine, A., Kumar, N., Keck, J., Duan, Z., Istanbulluoglu, E., Bandaragoda, C., Collins, B., Pfeiffer, A., "A mountain-to-coast hydrogeomorphic modeling framework for flood risk prediction" Poster Presentation at the Comminty Surface Dynamics Modeling System Meeting (May, 2019) Boulder, CO
Ahrendt, S. (Presenter), Istanbulluoglu, E., Horner-Devine, A., Mauger, G., Bandaragoda, C., Collins, B., Lundquist, J., Montgomery, D., Kumar, N., Shean, D., Pfeiffer, A., Morgan, J. A., Duan Z., Riedel, J., Kennard P., Anderson, S., Jaeger, K., Whorton E., "Integrated Modeling of HydroGeomorphic Hazards (MoHGeoH): Floods, landslides and sediment" Poster Presentation at the National Science Foundation PREEVENTS PI Meeting (Sept, 2018) Washington D.C.
Ahrendt, S. (Presenter), Abrams, D. "A Head-Specified Model; Concept Proof and Application in the Mahomet Aquifer", Presentation at the Mahomet Aquifer Consortium Meeting (July, 2018) Urbana, IL
Abrams, D. (Presenter), Ahrendt, S., Hadley, D. "Moving toward a real-time model of groundwater/surface water interactions in two heavily irrigated systems" Presentation at the International Congress on Environmental Modelling and Software (Jun, 2018)
Ahrendt, S. (Presenter), Jacobel, Christianson, Steig, Porter (2016). "A New Digital Elevation Model for Hercules Dome, Antarctica from CryoSat-2 Altimetry – Toward Site Selection for the Next Antarctic Deep Ice Core." Poster presentation at the American Geophysical Union Fall Conference (Dec, 2016).

I study rivers and the ways they transport sediment to understand flood hazard in the Pacific Northwest. I use data analysis, remote sensing and models to investigate how rivers are changing in shape and hydrologic regime.

PROJECTS

PUBLICATIONS

Ahrendt, S., Blom A., Van Denderen, R. P., Schielen, R. M. J., Horner-Devine, A. R., (in review) Geometric floodplain controls on riverbed elevation change within and between flood events

Ahrendt, S., Horner-Devine, A. R., Collins, B., Morgan, J., Istanbulluoglu, E., (2022) Channel Conveyance variability can influence flood risk as much as streamflow variaibility in western Washington State, Water Resources Research. https://doi.org/10.1029/2021WR031890

SELECTED PRESENTATIONS

Ahrendt, S. (Presenter), Horner-Devine, A., Kumar, N., Morgan, J. A., Collins, B., Istanbulluoglu, E. “Understanding Morphologic Flood Risk Relevant to River Management in Western Washington State” Oral Presentation at the American Geophysical Union Fall Meeting (Dec, 2020) Online

​​

Ahrendt, S. (Presenter), Horner-Devine, Kumar, N., A., Morgan, J. A., Collins, B., Istanbulluoglu, E. “River Morphology and Flood Risk in the Pacific Northwest” Oral Presentation at the Community Surface Dynamics Modeling System: Summer Science Series (July, 2020) Online

​

Ahrendt, S. (Presenter), Abrams, D. "A Head-Specified Model; Concept Proof and Application in the Mahomet Aquifer", Presentation at the Mahomet Aquifer Consortium Meeting (July, 2018) Urbana, IL

Abrams, D. (Presenter), Ahrendt, S., Hadley, D. "Moving toward a real-time model of groundwater/surface water interactions in two heavily irrigated systems" Presentation at the International Congress on Environmental Modelling and Software (Jun, 2018)

POSTERS