Zachary C. Johnson
Research Hydrologist for the Washington Water Science Center
My research interests are at the intersection of watershed hydrology, ecology, biogeochemistry, water and land management, and fluvial geomorphology using field measurements, remote sensing, laboratory, and modeling techniques. I am particularly passionate about topics such as surface-subsurface exchanges, terrestrial-aquatic linkages, anthropogenic interactions, statistical and deterministic modeling, and the importance of spatial and temporal scale for watershed processes.
Professional Experience
2023 to present – Research Hydrologist, US Geological Survey, Washington Water Science Center
2020 to 2023 – Hydrologist, US Geological Survey, Washington Water Science Center
2018 to 2020 – Research Associate/Scientist, University of Washington
2016 to 2017 – ORISE Postdoctoral Fellow, US Environmental Protection Agency
2014 to 2016 – Contractor/Research Ecologist, US Geological Survey, Leetown Science Center
Education and Certifications
Ph.D. 2014. Hydrology, University of Nevada, Reno, NV
M.S. 2010. Hydrology, University of Nevada, Reno, NV
B.A. 2007. ACS Chemistry (Mathematics minor), Concordia College, Moorhead, MN
Science and Products
Filter Total Items: 17
Inferring watershed hydraulics and cold-water habitat persistence using multi-year air and stream temperature signals Inferring watershed hydraulics and cold-water habitat persistence using multi-year air and stream temperature signals
Streams strongly influenced by groundwater discharge may serve as “climate refugia” for sensitive species in regions of increasingly marginal thermal conditions. The main goal of this study is to develop paired air and stream water annual temperature signal analysis techniques to elucidate the relative groundwater contribution to stream water and the effective groundwater flowpath depth...
Authors
Martin Briggs, Zachary C. Johnson, Craig Snyder, Nathaniel Hitt, Barret Kurylyk, Laura Lautz, Dylan Irvine, Stephen Hurley, John W. Lane
Forecasting stream habitat and Brook Trout responses to climate change in Catoctin Mountain Park Forecasting stream habitat and Brook Trout responses to climate change in Catoctin Mountain Park
Anticipating and mitigating the effects of climate change is a fundamental challenge for natural resource conservation. In this report, we respond to research needs identified by Catoctin Mountain Park (CATO) for native Brook Trout (Salvelinus fontinalis) conservation and management as part of the US Geological Survey (USGS) Natural Resources Preservation Program in FY15-16. We addressed...
Authors
Nathaniel Hitt, Craig Snyder, Erin Snook, Zachary Johnson, Matthew Morgan
Landform features and seasonal precipitation predict shallow groundwater influence on temperature in headwater streams Landform features and seasonal precipitation predict shallow groundwater influence on temperature in headwater streams
Headwater stream responses to climate change will depend in part on groundwater‐surface water exchanges. We used linear modeling techniques to partition likely effects of shallow groundwater seepage and air temperature on stream temperatures for 79 sites in nine focal watersheds using hourly air and water temperature measurements collected during summer months from 2012 to 2015 in...
Authors
Zachary Johnson, Craig Snyder, Nathaniel Hitt
Shallow bedrock limits groundwater seepage-based headwater climate refugia Shallow bedrock limits groundwater seepage-based headwater climate refugia
Groundwater/surface-water exchanges in streams are inexorably linked to adjacent aquifer dynamics. As surface-water temperatures continue to increase with climate warming, refugia created by groundwater connectivity is expected to enable cold water fish species to survive. The shallow alluvial aquifers that source groundwater seepage to headwater streams, however, may also be sensitive...
Authors
Martin Briggs, John Lane, Craig Snyder, Eric White, Zachary Johnson, David Nelms, Nathaniel Hitt
Transdisciplinary science: a path to understanding the interactions among ocean acidification, ecosystems, and society Transdisciplinary science: a path to understanding the interactions among ocean acidification, ecosystems, and society
The global nature of ocean acidification (OA) transcends habitats, ecosystems, regions, and science disciplines. The scientific community recognizes that the biggest challenge in improving understanding of how changing OA conditions affect ecosystems, and associated consequences for human society, requires integration of experimental, observational, and modeling approaches from many...
Authors
Kimberly Yates, Carol Turley, Brian Hopkinson, Anne Todgham, Jessica Cross, Holly Greening, Phillip Williamson, Ruben Van Hooidonk, Dimitri Deheyn, Zachary C. Johnson
Non-USGS Publications**
Johnson, Z.C., B.G. Johnson, M.A. Briggs, W.D. Devine, C.D. Snyder, N.P. Hitt, D.K. Hare, and T.V. Minkova (2020). “Paired air-water annual temperature patterns reveal hydrogeological controls on stream thermal regimes at watershed to continental scales”, J. Hydrology, 587, 124929.
Aho, K., J. Flotemersch, R. Hill, Z.C. Johnson, S.G. Leibowitz, and M. Weber (2020). “Adapting the Index of Watershed Integrity for watershed managers in the Western Balkans Region”, Environmental Management, 65, 602-617.
Johnson, Z.C., S.G. Leibowitz, and R.A. Hill (2019). “Revising the national maps of watershed integrity,” Sci. Total Environ., 651(2), 2615-2630.
Kuhn, A., S.G. Leibowitz, Z.C. Johnson, J. Lin, J.A. Massie, J.W. Hollister, J.L. Ebersole, J.L. Lake, J.R. Serbst, J. James, M.G. Bennett, J.R. Brooks, C.T. Nietch, N.J. Smucker, J.E. Flotemersch, L.C. Alexander, and J.E. Compton (2018). “Performance of national maps of watershed integrity at watershed scales,” Water, 10(5), 604.
Thornbrugh, D.J., S.G. Leibowitz, R.A. Hill, M.H. Weber, Z.C. Johnson, A.R. Olsen, J.E. Flotemersch, J.L. Stoddard, and D.V. Peck (2018). “Mapping watershed integrity for the conterminous United States,” Ecol. Ind., 85, 1133-1148.
Johnson, Z.C., J.J. Warwick, and R. Schumer (2015). “A numerical investigation of the potential impact of stream restoration on in-stream N removal,” Ecological Engineering 83, 96-107.
Johnson, Z.C., J.J. Warwick, and R. Schumer (2015). “Nitrogen retention in the main channel and two transient storage zones during nutrient addition experiments,” Limnology and Oceanography 60, 57-77.
Johnson, Z.C., J.J. Warwick, and R. Schumer (2014). “Factors affecting hyporheic and surface transient storage in a western U.S. river,” J. Hydrology 510, 325-339.
Booth, E.C., B.G. Berger, Z.C. Johnson, T.M. Ta, L.R. Weisel, D.J. Ulness (2006). "Analysis of Raman-enhanced nondegenerate four-wave mixing with factorized time correlator diagrams," J. Opt. Soc. Am. B 23, 885-892.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Filter Total Items: 15
Seismic data for study of shallow mountain bedrock limits seepage-based headwater climate refugia, Shenandoah National Park, Virginia Seismic data for study of shallow mountain bedrock limits seepage-based headwater climate refugia, Shenandoah National Park, Virginia
A combination of long-term daily temperature records and depth to bedrock measurements were used to parametrize one-dimensional models of shallow aquifer vertical heat transport in Shenandoah National Park, VA, USA. Depth to bedrock can directly influence shallow aquifer flow and thermal sensitivity, but is typically ill-defined along the stream corridor in steep mountain catchments. We...
Temperature data for study of shallow mountain bedrock limits seepage-based headwater climate refugia, Shenandoah National Park, Virginia Temperature data for study of shallow mountain bedrock limits seepage-based headwater climate refugia, Shenandoah National Park, Virginia
A combination of long-term daily temperature records and depth to bedrock measurements were used to parameterize one-dimensional models of shallow aquifer vertical heat transport in Shenandoah National Park, VA, USA. Spatially discontinuous roving water surface and bank temperatures surveys were performed with a handheld thermal infrared camera in September and December 2015 along the...
Air-water temperature data for the study of groundwater influence on stream thermal regimes in Shenandoah National Park, Virginia (ver. 2.0, May 3, 2018) Air-water temperature data for the study of groundwater influence on stream thermal regimes in Shenandoah National Park, Virginia (ver. 2.0, May 3, 2018)
USGS Leetown Science Center scientists collected hourly air and water temperature data at 79 site locations within nine watersheds in Shenandoah National Park, Virginia over four water years (2012-2015). Data were collected using HOBO Pro V2 thermographs (accuracy = 0.2 degrees Celsius, drift = less than 0.1 degrees Celsius per year per year).
Science and Products
Filter Total Items: 17
Inferring watershed hydraulics and cold-water habitat persistence using multi-year air and stream temperature signals Inferring watershed hydraulics and cold-water habitat persistence using multi-year air and stream temperature signals
Streams strongly influenced by groundwater discharge may serve as “climate refugia” for sensitive species in regions of increasingly marginal thermal conditions. The main goal of this study is to develop paired air and stream water annual temperature signal analysis techniques to elucidate the relative groundwater contribution to stream water and the effective groundwater flowpath depth...
Authors
Martin Briggs, Zachary C. Johnson, Craig Snyder, Nathaniel Hitt, Barret Kurylyk, Laura Lautz, Dylan Irvine, Stephen Hurley, John W. Lane
Forecasting stream habitat and Brook Trout responses to climate change in Catoctin Mountain Park Forecasting stream habitat and Brook Trout responses to climate change in Catoctin Mountain Park
Anticipating and mitigating the effects of climate change is a fundamental challenge for natural resource conservation. In this report, we respond to research needs identified by Catoctin Mountain Park (CATO) for native Brook Trout (Salvelinus fontinalis) conservation and management as part of the US Geological Survey (USGS) Natural Resources Preservation Program in FY15-16. We addressed...
Authors
Nathaniel Hitt, Craig Snyder, Erin Snook, Zachary Johnson, Matthew Morgan
Landform features and seasonal precipitation predict shallow groundwater influence on temperature in headwater streams Landform features and seasonal precipitation predict shallow groundwater influence on temperature in headwater streams
Headwater stream responses to climate change will depend in part on groundwater‐surface water exchanges. We used linear modeling techniques to partition likely effects of shallow groundwater seepage and air temperature on stream temperatures for 79 sites in nine focal watersheds using hourly air and water temperature measurements collected during summer months from 2012 to 2015 in...
Authors
Zachary Johnson, Craig Snyder, Nathaniel Hitt
Shallow bedrock limits groundwater seepage-based headwater climate refugia Shallow bedrock limits groundwater seepage-based headwater climate refugia
Groundwater/surface-water exchanges in streams are inexorably linked to adjacent aquifer dynamics. As surface-water temperatures continue to increase with climate warming, refugia created by groundwater connectivity is expected to enable cold water fish species to survive. The shallow alluvial aquifers that source groundwater seepage to headwater streams, however, may also be sensitive...
Authors
Martin Briggs, John Lane, Craig Snyder, Eric White, Zachary Johnson, David Nelms, Nathaniel Hitt
Transdisciplinary science: a path to understanding the interactions among ocean acidification, ecosystems, and society Transdisciplinary science: a path to understanding the interactions among ocean acidification, ecosystems, and society
The global nature of ocean acidification (OA) transcends habitats, ecosystems, regions, and science disciplines. The scientific community recognizes that the biggest challenge in improving understanding of how changing OA conditions affect ecosystems, and associated consequences for human society, requires integration of experimental, observational, and modeling approaches from many...
Authors
Kimberly Yates, Carol Turley, Brian Hopkinson, Anne Todgham, Jessica Cross, Holly Greening, Phillip Williamson, Ruben Van Hooidonk, Dimitri Deheyn, Zachary C. Johnson
Non-USGS Publications**
Johnson, Z.C., B.G. Johnson, M.A. Briggs, W.D. Devine, C.D. Snyder, N.P. Hitt, D.K. Hare, and T.V. Minkova (2020). “Paired air-water annual temperature patterns reveal hydrogeological controls on stream thermal regimes at watershed to continental scales”, J. Hydrology, 587, 124929.
Aho, K., J. Flotemersch, R. Hill, Z.C. Johnson, S.G. Leibowitz, and M. Weber (2020). “Adapting the Index of Watershed Integrity for watershed managers in the Western Balkans Region”, Environmental Management, 65, 602-617.
Johnson, Z.C., S.G. Leibowitz, and R.A. Hill (2019). “Revising the national maps of watershed integrity,” Sci. Total Environ., 651(2), 2615-2630.
Kuhn, A., S.G. Leibowitz, Z.C. Johnson, J. Lin, J.A. Massie, J.W. Hollister, J.L. Ebersole, J.L. Lake, J.R. Serbst, J. James, M.G. Bennett, J.R. Brooks, C.T. Nietch, N.J. Smucker, J.E. Flotemersch, L.C. Alexander, and J.E. Compton (2018). “Performance of national maps of watershed integrity at watershed scales,” Water, 10(5), 604.
Thornbrugh, D.J., S.G. Leibowitz, R.A. Hill, M.H. Weber, Z.C. Johnson, A.R. Olsen, J.E. Flotemersch, J.L. Stoddard, and D.V. Peck (2018). “Mapping watershed integrity for the conterminous United States,” Ecol. Ind., 85, 1133-1148.
Johnson, Z.C., J.J. Warwick, and R. Schumer (2015). “A numerical investigation of the potential impact of stream restoration on in-stream N removal,” Ecological Engineering 83, 96-107.
Johnson, Z.C., J.J. Warwick, and R. Schumer (2015). “Nitrogen retention in the main channel and two transient storage zones during nutrient addition experiments,” Limnology and Oceanography 60, 57-77.
Johnson, Z.C., J.J. Warwick, and R. Schumer (2014). “Factors affecting hyporheic and surface transient storage in a western U.S. river,” J. Hydrology 510, 325-339.
Booth, E.C., B.G. Berger, Z.C. Johnson, T.M. Ta, L.R. Weisel, D.J. Ulness (2006). "Analysis of Raman-enhanced nondegenerate four-wave mixing with factorized time correlator diagrams," J. Opt. Soc. Am. B 23, 885-892.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Filter Total Items: 15
Seismic data for study of shallow mountain bedrock limits seepage-based headwater climate refugia, Shenandoah National Park, Virginia Seismic data for study of shallow mountain bedrock limits seepage-based headwater climate refugia, Shenandoah National Park, Virginia
A combination of long-term daily temperature records and depth to bedrock measurements were used to parametrize one-dimensional models of shallow aquifer vertical heat transport in Shenandoah National Park, VA, USA. Depth to bedrock can directly influence shallow aquifer flow and thermal sensitivity, but is typically ill-defined along the stream corridor in steep mountain catchments. We...
Temperature data for study of shallow mountain bedrock limits seepage-based headwater climate refugia, Shenandoah National Park, Virginia Temperature data for study of shallow mountain bedrock limits seepage-based headwater climate refugia, Shenandoah National Park, Virginia
A combination of long-term daily temperature records and depth to bedrock measurements were used to parameterize one-dimensional models of shallow aquifer vertical heat transport in Shenandoah National Park, VA, USA. Spatially discontinuous roving water surface and bank temperatures surveys were performed with a handheld thermal infrared camera in September and December 2015 along the...
Air-water temperature data for the study of groundwater influence on stream thermal regimes in Shenandoah National Park, Virginia (ver. 2.0, May 3, 2018) Air-water temperature data for the study of groundwater influence on stream thermal regimes in Shenandoah National Park, Virginia (ver. 2.0, May 3, 2018)
USGS Leetown Science Center scientists collected hourly air and water temperature data at 79 site locations within nine watersheds in Shenandoah National Park, Virginia over four water years (2012-2015). Data were collected using HOBO Pro V2 thermographs (accuracy = 0.2 degrees Celsius, drift = less than 0.1 degrees Celsius per year per year).