John C. Hammond, PhD
John Hammond is a Research Hydrologist for the U.S. Geological Survey, currently working at the MD-DE-DC Water Science Center in the Baltimore office.
John studies hydroclimatic variability and trends, seasonal snow dynamics, empirical streamflow relationships across scales, and incorporates satellite data into hydrologic models. Current projects include improving snow process representation in hydrologic models, characterizing hydrologic drought, developing drought early warning systems, and drivers of non-perennial flow, and DC StreamStats.
Research interests include:
- Runoff forecasting in snow-dominated watersheds
- Input partitioning through the critical zone
- Hydroclimatic and cryospheric trend detection
- Low-cost sensors for snow and streamflow monitoring
- Intermittent snow and streamflow occurrence and prediction
Consulting experience:
- Remote sensing of snow occurrence timing and distribution
- Flood innundation mapping
- Hydrologic and meteorologic equipment installation and maintenance
Professional Experience
Research Hydrologist, U.S. Geological Survey (USGS), November, 2022 to Present: Surface water hydrologist (Water Science Center, Water Mission Area)
Hydrologist, U.S. Geological Survey (USGS)
March, 2019 to November, 2022: Surface water hydrologist (Water Science Center, Water Mission Area)U.S. Geological Survey (USGS)
November, 2014 to December, 2015: Surface Water Research Contractor
Education and Certifications
2018. PhD, Geosciences: Watershed Science, Colorado State University. Dissertation: Effects of snow persistence on soil moisture and streamflow generation in mountain regions of the western U.S.
2014. M.S., Water Resources Science, Oregon State University. Thesis: Trends in streamflow above and below dams across the Columbia River Basin from 1950 to 2012: assessing sub-basin sensitivity.
2012. B.S., Environmental Science & Policy, University of Maryland, College Park. Concentration: Global Environmental Change. Citation: College Park Scholars – Environmental Studies. Cum Laude.
Science and Products
Filter Total Items: 34
Peak-flow and low-flow magnitude estimates at defined frequencies and durations for nontidal streams in Delaware Peak-flow and low-flow magnitude estimates at defined frequencies and durations for nontidal streams in Delaware
Reliable estimates of the magnitude of peak flows in streams are required for the economical and safe design of transportation and water conveyance structures. In addition, reliable estimates of the magnitude of low flows at defined frequencies and durations are needed for meeting regulatory requirements, quantifying base flows in streams and rivers, and evaluating time of travel and...
Authors
John C. Hammond, Edward J. Doheny, Jonathan J.A. Dillow, Mark R. Nardi, Peter A. Steeves, Daniel L. Warner
Quantifying streamflow depletion from groundwater pumping: A practical review of past and emerging approaches for water management Quantifying streamflow depletion from groundwater pumping: A practical review of past and emerging approaches for water management
Groundwater pumping can cause reductions in streamflow (“streamflow depletion”) that must be quantified for conjunctive management of groundwater and surface water resources. However, streamflow depletion cannot be measured directly and is challenging to estimate because pumping impacts are masked by streamflow variability due to other factors. Here, we conduct a management-focused...
Authors
Samuel Zipper, William H. Farmer, Andrea E. Brookfield, Hoori Ajami, Howard W. Reeves, Chloe Wardropper, John C. Hammond, Tom Gleeson, Jillian M. Deines
Pervasive changes in stream intermittency across the United States Pervasive changes in stream intermittency across the United States
Non-perennial streams are widespread, critical to ecosystems and society, and the subject of ongoing policy debate. Prior large-scale research on stream intermittency has been based on long-term averages, generally using annually aggregated data to characterize a highly variable process. As a result, it is not well understood if, how, or why the hydrology of non-perennial streams is...
Authors
Samuel Zipper, John C. Hammond, Margaret Shanafield, Margaret Zimmer, Thibault Datry, C. Nathan Jones, Kendra E. Kaiser, Sarah E. Godsey, Ryan Burrow, Joanna Blaszczak, Michelle Busch, Adam N. Price, Kate Boersma, Adam Ward, Katie Costigan, George H. Allen, Corey Krabbenhoft, Walter Dodds, Meryl C. Mims, Julian Olden, Stephanie K. Kampf, Amy J. Burgin, Daniel C. Allen
Managing nonperennial headwater streams in temperate forests of the United States Managing nonperennial headwater streams in temperate forests of the United States
Forest management guidelines are designed to protect water quality from unintended effects of land use changes such as timber harvest, mining, or forest road construction. Although streams that periodically cease to flow (nonperennial) drain the majority of forested areas, these streams are not consistently included in forest management guidelines. This paper reviews management...
Authors
Stephanie K. Kampf, Kathleen Dwyer, Matthew P. Fairchild, Jason B. Dunham, Craig D. Snyder, Kristin L. Jaeger, Charles H. Luce, John C. Hammond, Codie Wilson, Margaret Zimmer, Marielle Sidell
The drying regimes of non-perennial rivers and streams The drying regimes of non-perennial rivers and streams
The flow regime paradigm is central to the aquatic sciences, where flow drives critical functions in lotic systems. Non-perennial streams comprise the majority of global river length, thus we extended this paradigm to stream drying. Using 894 USGS gages, we isolated 25,207 drying events from 1979 to 2018, represented by a streamflow peak followed by no flow. We calculated hydrologic...
Authors
Adam N. Price, C. Nathan Jones, John C. Hammond, Margaret Zimmer, Samuel Zipper
Evaluating low flow patterns, drivers and trends in the Delaware River Basin Evaluating low flow patterns, drivers and trends in the Delaware River Basin
In the humid, temperate Delaware River Basin (DRB) where water availability is generally reliable, summer low flows can cause competition between various human and ecological water uses. As temperatures continue to rise, population increases and development expands, it is critical to understand historical low flow variability to anticipate and plan for future flows. Using a sample of 325...
Authors
John C. Hammond, Brandon J. Fleming
Spatial patterns and drivers of nonperennial flow regimes in the contiguous United States Spatial patterns and drivers of nonperennial flow regimes in the contiguous United States
Over half of global rivers and streams lack perennial flow, and understanding the distribution and drivers of their flow regimes is critical for understanding their hydrologic, biogeochemical, and ecological functions. We analyzed nonperennial flow regimes using 540 U.S. Geological Survey watersheds across the contiguous United States from 1979 to 2018. Multivariate analyses revealed...
Authors
John C. Hammond, Margaret Zimmer, Margaret Shanafield, Kendra E. Kaiser, Sarah E Godsey, Meryl C. Mims, Samuel Zipper, Ryan Burrow, Stephanie K. Kampf, Walter Dodds, C. Nathan Jones, Corey Krabbenhoft, Kate Boersma, Thibault Datry, Julian D. Olden, George H. Allen, Adam N. Price, Katie H. Costigan, Rebecca Hale, Adam S Ward, Daniel C. Allen
Zero or not? Causes and consequences of zero-flow stream gage readings Zero or not? Causes and consequences of zero-flow stream gage readings
Streamflow observations can be used to understand, predict, and contextualize hydrologic, ecological, and biogeochemical processes and conditions in streams. Stream gages are point measurements along rivers where streamflow is measured, and are often used to infer upstream watershed‐scale processes. When stream gages read zero, this may indicate that the stream has dried at this location...
Authors
Margaret Zimmer, Kendra E. Kaiser, Joanna Blaszczak, Samuel Zipper, John C. Hammond, Ken M. Fritz, Katie H. Costigan, Jacob D. Hosen, Sarah E Godsey, George H. Allen, Stephanie K. Kampf, Ryan Burrow, Corey Krabbenhoft, Walter Dodds, Rebecca Hale, Julian D. Olden, Margaret Shanafield, Amanda DelVecchia, Adam S Ward, Meryl C. Mims, Thibault Datry, Michael A. Bogan, Kate Boersma, Michelle Busch, Nathan M. Jones, Amy Burgin, Daniel C. Allen
Sub-annual streamflow responses to rainfall and snowmelt inputs in snow-dominated watersheds of the western U.S. Sub-annual streamflow responses to rainfall and snowmelt inputs in snow-dominated watersheds of the western U.S.
Streamflow generation in mountain watersheds is strongly influenced by snow accumulation and melt, and multiple studies have found that snow loss leads to earlier snowmelt timing and declines in annual streamflow. However, hydrologic responses to snow loss are heterogeneous, and not all areas experience streamflow declines. This research examines whether streamflow generation is...
Authors
John C. Hammond, Stephanie K. Kampf
Runoff sensitivity to snow depletion curve representation within a continental scale hydrologic model Runoff sensitivity to snow depletion curve representation within a continental scale hydrologic model
The spatial variability of snow water equivalent (SWE) can exert a strong influence on the timing and magnitude of snowmelt delivery to a watershed. Therefore, the representation of subgrid or subwatershed snow variability in hydrologic models is important for accurately simulating snowmelt dynamics and runoff response. The U.S. Geological Survey National Hydrologic Model infrastructure...
Authors
Graham A. Sexstone, Jessica M. Driscoll, Lauren Hay, John C. Hammond, Theodore B. Barnhart
Filter Total Items: 25
Contiguous US and Global streamflow gages measuring zero flow Contiguous US and Global streamflow gages measuring zero flow
We report the site number and locations of 5798 streamflow gages displaying zero flow for at least one day in their daily records. 4891 of these gages are from the GRDC network, and 906 are USGS gages in the contiguous US. Additionally, provisional data for two USGS gages 1) Rio Puerco near Bernardo, NM (USGS site: 08353000) and 2) Agua Fria River Near Mayer, AZ (USGS site: 09512500) are...
Science and Products
Filter Total Items: 34
Peak-flow and low-flow magnitude estimates at defined frequencies and durations for nontidal streams in Delaware Peak-flow and low-flow magnitude estimates at defined frequencies and durations for nontidal streams in Delaware
Reliable estimates of the magnitude of peak flows in streams are required for the economical and safe design of transportation and water conveyance structures. In addition, reliable estimates of the magnitude of low flows at defined frequencies and durations are needed for meeting regulatory requirements, quantifying base flows in streams and rivers, and evaluating time of travel and...
Authors
John C. Hammond, Edward J. Doheny, Jonathan J.A. Dillow, Mark R. Nardi, Peter A. Steeves, Daniel L. Warner
Quantifying streamflow depletion from groundwater pumping: A practical review of past and emerging approaches for water management Quantifying streamflow depletion from groundwater pumping: A practical review of past and emerging approaches for water management
Groundwater pumping can cause reductions in streamflow (“streamflow depletion”) that must be quantified for conjunctive management of groundwater and surface water resources. However, streamflow depletion cannot be measured directly and is challenging to estimate because pumping impacts are masked by streamflow variability due to other factors. Here, we conduct a management-focused...
Authors
Samuel Zipper, William H. Farmer, Andrea E. Brookfield, Hoori Ajami, Howard W. Reeves, Chloe Wardropper, John C. Hammond, Tom Gleeson, Jillian M. Deines
Pervasive changes in stream intermittency across the United States Pervasive changes in stream intermittency across the United States
Non-perennial streams are widespread, critical to ecosystems and society, and the subject of ongoing policy debate. Prior large-scale research on stream intermittency has been based on long-term averages, generally using annually aggregated data to characterize a highly variable process. As a result, it is not well understood if, how, or why the hydrology of non-perennial streams is...
Authors
Samuel Zipper, John C. Hammond, Margaret Shanafield, Margaret Zimmer, Thibault Datry, C. Nathan Jones, Kendra E. Kaiser, Sarah E. Godsey, Ryan Burrow, Joanna Blaszczak, Michelle Busch, Adam N. Price, Kate Boersma, Adam Ward, Katie Costigan, George H. Allen, Corey Krabbenhoft, Walter Dodds, Meryl C. Mims, Julian Olden, Stephanie K. Kampf, Amy J. Burgin, Daniel C. Allen
Managing nonperennial headwater streams in temperate forests of the United States Managing nonperennial headwater streams in temperate forests of the United States
Forest management guidelines are designed to protect water quality from unintended effects of land use changes such as timber harvest, mining, or forest road construction. Although streams that periodically cease to flow (nonperennial) drain the majority of forested areas, these streams are not consistently included in forest management guidelines. This paper reviews management...
Authors
Stephanie K. Kampf, Kathleen Dwyer, Matthew P. Fairchild, Jason B. Dunham, Craig D. Snyder, Kristin L. Jaeger, Charles H. Luce, John C. Hammond, Codie Wilson, Margaret Zimmer, Marielle Sidell
The drying regimes of non-perennial rivers and streams The drying regimes of non-perennial rivers and streams
The flow regime paradigm is central to the aquatic sciences, where flow drives critical functions in lotic systems. Non-perennial streams comprise the majority of global river length, thus we extended this paradigm to stream drying. Using 894 USGS gages, we isolated 25,207 drying events from 1979 to 2018, represented by a streamflow peak followed by no flow. We calculated hydrologic...
Authors
Adam N. Price, C. Nathan Jones, John C. Hammond, Margaret Zimmer, Samuel Zipper
Evaluating low flow patterns, drivers and trends in the Delaware River Basin Evaluating low flow patterns, drivers and trends in the Delaware River Basin
In the humid, temperate Delaware River Basin (DRB) where water availability is generally reliable, summer low flows can cause competition between various human and ecological water uses. As temperatures continue to rise, population increases and development expands, it is critical to understand historical low flow variability to anticipate and plan for future flows. Using a sample of 325...
Authors
John C. Hammond, Brandon J. Fleming
Spatial patterns and drivers of nonperennial flow regimes in the contiguous United States Spatial patterns and drivers of nonperennial flow regimes in the contiguous United States
Over half of global rivers and streams lack perennial flow, and understanding the distribution and drivers of their flow regimes is critical for understanding their hydrologic, biogeochemical, and ecological functions. We analyzed nonperennial flow regimes using 540 U.S. Geological Survey watersheds across the contiguous United States from 1979 to 2018. Multivariate analyses revealed...
Authors
John C. Hammond, Margaret Zimmer, Margaret Shanafield, Kendra E. Kaiser, Sarah E Godsey, Meryl C. Mims, Samuel Zipper, Ryan Burrow, Stephanie K. Kampf, Walter Dodds, C. Nathan Jones, Corey Krabbenhoft, Kate Boersma, Thibault Datry, Julian D. Olden, George H. Allen, Adam N. Price, Katie H. Costigan, Rebecca Hale, Adam S Ward, Daniel C. Allen
Zero or not? Causes and consequences of zero-flow stream gage readings Zero or not? Causes and consequences of zero-flow stream gage readings
Streamflow observations can be used to understand, predict, and contextualize hydrologic, ecological, and biogeochemical processes and conditions in streams. Stream gages are point measurements along rivers where streamflow is measured, and are often used to infer upstream watershed‐scale processes. When stream gages read zero, this may indicate that the stream has dried at this location...
Authors
Margaret Zimmer, Kendra E. Kaiser, Joanna Blaszczak, Samuel Zipper, John C. Hammond, Ken M. Fritz, Katie H. Costigan, Jacob D. Hosen, Sarah E Godsey, George H. Allen, Stephanie K. Kampf, Ryan Burrow, Corey Krabbenhoft, Walter Dodds, Rebecca Hale, Julian D. Olden, Margaret Shanafield, Amanda DelVecchia, Adam S Ward, Meryl C. Mims, Thibault Datry, Michael A. Bogan, Kate Boersma, Michelle Busch, Nathan M. Jones, Amy Burgin, Daniel C. Allen
Sub-annual streamflow responses to rainfall and snowmelt inputs in snow-dominated watersheds of the western U.S. Sub-annual streamflow responses to rainfall and snowmelt inputs in snow-dominated watersheds of the western U.S.
Streamflow generation in mountain watersheds is strongly influenced by snow accumulation and melt, and multiple studies have found that snow loss leads to earlier snowmelt timing and declines in annual streamflow. However, hydrologic responses to snow loss are heterogeneous, and not all areas experience streamflow declines. This research examines whether streamflow generation is...
Authors
John C. Hammond, Stephanie K. Kampf
Runoff sensitivity to snow depletion curve representation within a continental scale hydrologic model Runoff sensitivity to snow depletion curve representation within a continental scale hydrologic model
The spatial variability of snow water equivalent (SWE) can exert a strong influence on the timing and magnitude of snowmelt delivery to a watershed. Therefore, the representation of subgrid or subwatershed snow variability in hydrologic models is important for accurately simulating snowmelt dynamics and runoff response. The U.S. Geological Survey National Hydrologic Model infrastructure...
Authors
Graham A. Sexstone, Jessica M. Driscoll, Lauren Hay, John C. Hammond, Theodore B. Barnhart
Filter Total Items: 25
Contiguous US and Global streamflow gages measuring zero flow Contiguous US and Global streamflow gages measuring zero flow
We report the site number and locations of 5798 streamflow gages displaying zero flow for at least one day in their daily records. 4891 of these gages are from the GRDC network, and 906 are USGS gages in the contiguous US. Additionally, provisional data for two USGS gages 1) Rio Puerco near Bernardo, NM (USGS site: 08353000) and 2) Agua Fria River Near Mayer, AZ (USGS site: 09512500) are...