Undergraduate research is fundamental to training the next generation of earth scientists. My research strives to drive students to complete excellent, publication ready research at the undergraduate level. In fact, I view undergraduate research as the perfect hybrid between teaching and research at a liberal arts school. Roughly 30% of students that work in my lab end up with a peer-reviewed publication in a well-regarded journal.
My research is broadly focused on post-glacial landscape evolution. I specialize in the use of soil development in providing relative ages of landforms including terraces, hillslopes, and dunes. This approach can be can be calibrated using absolute ages and soils can also be used to contextualize those ages as understanding soil horizonation is useful in detecting landscape disturbance.
In recent years, my students have increasingly focused on how landscapes of the southeastern US have been impacted by Euro-American settlers. This includes published work on gullies in the Piedmont as well as on-going work on stream incision in the Piedmont and sedimentation associated with deforestation in the Blue Ridge.
We also use sediment cores to understand periods of sedimentation in various environments. In the Rocky Mountains, we used sediment cores in bogs to understand paleoclimate and the timing of landscape evolution. More recently, we have been using cores to examine anthropogenic sedimentation rates in the reservoirs of the Piedmont. Specifically, we have been looking at sedimentation on deltas to determine the impact of upstream development.
I also run a series of stream gauges on headwater streams in the Davidson area. Data from these gauges provides a rare record of discharge on very small streams. We use this data both in class and as part of student research projects.
Ongoing projects include:
- Anthropogenic impacts on fluvial systems in the North Carolina Piedmont including increased soil erosion in the past 200 years, increased sedimentation in local reservoirs, incision along streams, and increases in discharge associated with development. The goal of this work is to understand the pre-Euroamerican settlement state of streams in the region to better inform modern stream management.
- Coring of deltas in Lake Wylie to determine the impact of upstream development. This study is funded by Mecklenburg County with the goal of getting ahead of issues related to cove infilling in southwest Charlotte. I have shared our preliminary results with government agencies in Gaston County.
- Mapping of natural and anthropogenic terrace sequences in the Blue Ridge Mountains. The goal of this work is to understand the impacts of Euroamerican settlement in the Blue Ridge by identifying both legacy sediments and natural terraces.
- The timing of post-glacial terrace formation along the Rio Grande River in southern Colorado. This project focuses on how and when terraces formed after the retreat of glaciers in the region. Specifically, the presence of Holocene terraces would indicate that some climate event allowed for stable aggradation well after deglaciation.
My most recent publications include (* indicates Davidson student author):
Eppes, M.C., Johnson, B.G., Describing soils in the field: a manual for geomorphologists, Treatise on Geomorphology (2nd Edition), 3, 450-479 2022.
Johnson, B.G., An Overview of Soil Geomorphology in North Carolina, Carolina Geological Survey 2022 Meeting and Field Trip, Guidebook for the 82nd Annual CGS Meeting, 2022.
Stiefel, W.C.*, Cooley, S.C.*, Johnson, B.G., Increased colluvial hollow discharge and subsequent recovery after a low intensity wildfire in the Blue Ridge Mountains, USA, Hydrological Processes, 35, e13971, 2021. https://doi.org/10.1002/hyp.13971
Johnson, B.G., Stream capture and the geomorphic evolution of Linville Gorge in the southern Appalachians, USA, Geomorphology, 368, 2020. https://doi.org/10.1016/j.geomorph.2020.107360
Beeton, Jared, Johnson, Bradley, Geomorphology and Climate Change in the San Luis Valley, in The Geology, Ecology, and Human History of the San Luis Valley, University of Colorado Press, 2020.
Fulop, Emma*, Johnson, B.G., Keen-Zebert, A., A geochronology supported soil chronosequence for establishing the timing of shoreline parabolic dune stabilization, Catena, 178, 232-243, 2019. https://doi.org/10.1016/j.catena.2019.03.018
Spell, Rosalind*, Johnson, B.G. Anthropogenic alluvial sediments in North Carolina Piedmont gullies indicate swift geomorphic response to 18th century land-use practices, Physical Geography, 40: 6, 2019. https://doi.org/10.1080/02723646.2019.1574145