John C Hammond, PhD

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 assessing patterns and drivers of non-perennial flow.



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.


Harrison, H.N., Hammond, J.C., Kampf, S.K., Kiewiet, L. (2021). On the hydrological difference between catchments above and below the intermittent-persistent snow transition in the Colorado Front Range. Hydrologic Processes.

Zipper, S. C., Hammond, J. C., Shanafield, M., Zimmer, M., Datry, T., Jones, C. N., ... & Allen, D. C. (2021). Pervasive changes in stream intermittency across the United States. Environmental Research Letters16(8), 084033. 

Hammond, J.C., Fleming, B.J. (2021). Evaluating low flow patterns, drivers and trends in the Delaware River Basin. Journal of Hyrdrology.

Hammond, J. C., Zimmer, M., Shanafield, M., Kaiser, K., Godsey, S. E., Mims, M. C., ... & Allen, D. C. (2020). Spatial patterns and drivers of non‐perennial flow regimes in the contiguous US. Geophysical Research Letters

Kampf, S.K., Dwire, K.A., Fairchild, M.P., Dunham, J., Snyder, C.D., Jaeger, K.L., Luce, C.H., Hammond, J.C., Wilson, C., Zimmer, M.A., Sidell, M. (2021). Managing non-perennial headwater streams in temperate forests of the United States. Forest Ecology and Management.

Price, A.N., Jones, C.N., Hammond, J.C., Zimmer, M.A., Zipper, S.C. (2021). The Drying Regimes of Non-Perennial Rivers and Streams. Geophysical Research Letters

Sauquet, E., Shanafield, M., Hammond, J.C., Sefton, C., Leigh, C., & Datry, T. (2021). Classification and trends in intermittent river flow regimes in Australia, northwestern Europe and USA: a global perspective. Journal of Hydrology

Eurich A., Kampf, S.K., Hammond, J.C., Ross, M., Willi, K., Vorester, A.G. (2021). Predicting mean annual and mean monthly streamflow in Colorado ungauged basins. River Research and Applications

Martin, C., Kampf, S.K., Hammond, J.C., Wilson, C., Anderson, S. (2021). Controls on Streamflow Densities in Semiarid Rocky Mountain Catchments. Water. 13(4), 521;

Robles, M.D., Hammond, J.C., Kampf, S.K., Biederman, J.C., Demaria, E.M.C. (2020). Winter Rain-on-Snow Buffers Streamflow Sensitivity to Snowpack Losses in the Salt River Watershed in Semi-Arid Southwest. Water. 13(1), 3;

Jones, J.A., Hammond, J.C. (2020). River management response to multi‐decade changes in timing of reservoir inflows, Columbia River Basin, USA. Hydrological Processes

Kampf, S.K., Burges S.J., Hammond, J.C., Covinom T.P., Eurich, A., Harrison, H., Martin, C., Puntenney-Desmond, K. (2020). The case for an open water balance: Reenvisioning network design and data analysis for a complex, uncertain world. Water Resources Research, e2019WR026699.

Hammond, J. C., & Kampf, S. K. (2020). Subannual streamflow responses to rainfall and snowmelt inputs in snow‐dominated watersheds of the western United States. Water Resources Research, 56, e2019WR026132.

Zimmer, M.A., Kaiser, K.E., Blaszczak, J.R., Zipper, S.C., Hammond, J.C., …Allen, D.C. (2020). Zero or not? Causes and consequences of zero‐flow stream gage readings. Wiley Interdisciplinary Reviews7(3).

Sexstone, G. A., Driscoll, J. M., Hay, L. E., Hammond, J. C., & Barnhart, T. B. (2020). Runoff sensitivity to snow depletion curve representation within a continental scale hydrologic model. Hydrological Processes

Hammond, J. C., Harpold, A. A., Weiss, S., and Kampf, S. K. (2019). Partitioning snowmelt and rainfall in the critical zone: effects of climate type and soil properties, Hydrol. Earth Syst. Sci.,

Hammond, J. C., Saavedra, F. A., & Kampf, S. K. (2018). How does snow persistence relate to annual streamflow in mountain watersheds of the Western U.S. with wet maritime and dry continental climates? Water Resources Research, 54.

Hammond, J. C., Saavedra, F. A., & Kampf, S. K. (2018). Global snow zone maps and trends in snow persistence 2001-2016. International Journal of Climatology.

Busch, M.H.; Costigan, K.H.; Fritz, K.M.; Datry, T.; Krabbenhoft, C.A.; Hammond, J.C.; Zimmer, M.; Olden, J.D.; Burrows, R.M.; Dodds, W.K.; Boersma, K.S.; Shanafield, M.; Kampf, S.K.; Mims, M.C.; Bogan, M.T.; Ward, A.S.; Perez Rocha, M.; Godsey, S.; Allen, G.H.; Blaszczak, J.R.; Jones, C.N.; Allen, D.C. (2020). What’s in a Name? Patterns, Trends, and Suggestions for Defining Non-Perennial Rivers and Streams. Water12, 1980.

Kampf, S., Strobl, B., Hammond, J.C., Anenberg, A., Etter, S., Martin, C., Puntenney-Desmond, K., Seibert, J., and I. van Meerveld (2018), Testing the waters: Mobile apps for crowdsourced streamflow data, EOS, 99, 

Shanafield, M., Godsey S., Datry, T., Hale, R. , Zipper, S., Costigan, K., Krabbenhoft, C., Dodds, W., Zimmer, M., Allen, D., Bogan, M., Kaiser, K., Burrows, R., Hammond, J.C., Busch, M., Kampf, S., Mims, M., Burgin, A., and J. Olden (2020), Science gets up to speed on dry rivers, EOS, 101, Published on 13 February 2020.

In preparation or review

Barnhart, T.B., Farmer, W.H., Hammond, J.C., Sexstone, G.A., Curran, J.H., Koch, J.C., and Driscoll, J.M. (in review),  Evaluating hydrologic region assignment techniques for ungaged basins in Alaska, USA: River Research and Applications

Krabbenhoft, C.A., Allen, G.H., Lin, P., Godsey, S.E., Allen, D.C., Burrows, R.M., DelVecchia, A.G., Fritz, K.M., Shanafield, M., Burgin, A.J., Zimmer, M.A., Datry, T., Dodds, W.K., Jones, C.N., Mims, M.C., Franklin, C., Hammond, J.C., Zipper, S.C., Ward, A.S., Costigan, K.H., Beck, H.E., Olden, J.D. Assessing placement bias of the global river gauge network, Nature Geoscience.

Zipper, S.C.; Farmer, W.H.; Brookfield, A.; Ajami, H.; Reeves, H.W.; Wardropper, C.; Hammond, J.C.; Gleeson, T.; Deines, J.M. (In review). Quantifying streamflow depletion from groundwater pumping: A practical review of past and potential approaches for water management. Journal of the American Water Resources Association.

Barnhart, T.B., Farmer, W.H., Hammond, J.C., Sexstone, G.A., Curran, J.H., Koch, J.C., Driscoll, J.M. (In review). Evaluating hydrologic region assignment techniques for ungaged basins in Alaska, USA. River Research and Applications.

Hammond, J.C., Dillow, J.J., Doheny, E.J.; Nardi, M.R.; Steeves, P.A.; Warner, D.L. (In review). Peak-Flow and Low-Flow Magnitude Estimates at Defined Frequencies and Durations for Nontidal Streams in Delaware. USGS Scientific Information Report.

Kampf, S.K., Bhaskar, A.S., Green, T.R., Hammond, J.C., Erskine, R.H., Johnson, A., MacDonald, L., Schmeer, S., Sosa Pérez, G., Wagenbrenner, J., Wilson, C. (In preparation). Empirical and model-derived rainfall thresholds for infiltration excess overland flow and surface erosion. Journal of Hydrologic Engineering.

Other relevant reports

Kampf, S.K., Eurich, A., Hammond, J.C., Livneh, B., Cepeda, J. (2019). Streamflow prediction in Colorado ungauged basins. Final Report Submitted to Colorado Water Conservation Board.

Kampf, S.K., Hammond, J.C., Eurich, A., Puntenney-Desmond, K. (2018). When and where does river flow originate? Colorado Water Newsletter March/April, Colorado Water Institute, Colorado State University.

Richard, G., Eurich, A. Hammond, J.C., Kampf, S.K. (2018). Water Yield Sensitivity to Snow Loss in Colorado Headwater Streams. Colorado Water Newsletter May/June, Colorado Water Institute, Colorado State University.

Journal Reviewer

Water Resources Research (

Geophysical Research Letters (

Hydrology and Earth System Sciences (

Hydrological Sciences Journal (

Hydrological Processes (

Journal of Hydrology (

Earth's Future (

Water (

Data visualizations 

Nell, C.S., Bechtel, E., Wernimont, M., Corson-Dosch, H., Platt, L., Barnhart, T., Hammond, J.C., Putman, A., Sexstone, G., Driscoll, J. From Snow to Flow: what changing snowmelt means for water in the Western U.S. USGS Water Mission Area. 27 April 2021,