Staff profile

since 07/2024 — Associate Professor, Earth Sciences, Durham University

12/2020 - 06/2024 — Assistant Professor, Earth Sciences, Durham University

06/2020 - 11/2020 — Oberassistent (Senior Research Assistant), ETZ Zurich

05/2018 - 05/2020 — Postdoctoral Fellow, ETH Zurich

06/2017 - 04/2018 — Postdoctoral Researcher, University of Tuebingen

10/2013 - 05/2017 — PhD student, University of Tuebingen

• Catchment hydrology
• Groundwater-surface water interactions
• Hydrology
• Rivers & streams
• Stable water isotopes
• Tracers of flowpaths
• Water quality

Chapter in book

• Using diel solute signals to assess ecohydrological processing in lotic systems
  Knapp, J. (2023). Using diel solute signals to assess ecohydrological processing in lotic systems. In S. Krause, D. M. Hannah, & N. B. Grimm (Eds.), Ecohydrological Interfaces. Wiley

Journal Article

• Concentration‐Discharge Relationships Revisited: Overused But Underutilised?
  Knapp, J. L. A., & Musolff, A. (2024). Concentration‐Discharge Relationships Revisited: Overused But Underutilised?. Hydrological Processes, 38(11), Article e15328. https://doi.org/10.1002/hyp.15328
• Multi-year time series of daily solute and isotope measurements from three Swiss pre-Alpine catchments
  Knapp, J. L. A., Napitupulu, T., von Freyberg, J., Rücker, A., Studer, B., Zappa, M., & Kirchner, J. W. (2024). Multi-year time series of daily solute and isotope measurements from three Swiss pre-Alpine catchments. Scientific Data, 11(1), 393. https://doi.org/10.1038/s41597-024-03192-5
• River water quality shaped by land–river connectivity in a changing climate
  Li, L., Knapp, J. L. A., Lintern, A., Ng, G.-H. C., Perdrial, J., Sullivan, P. L., & Zhi, W. (2024). River water quality shaped by land–river connectivity in a changing climate. Nature Climate Change, 14(3), 225-237. https://doi.org/10.1038/s41558-023-01923-x
• The heat is on: Predicting urban stream temperature responses to summer storms
  Knapp, J. L. A., & Kelleher, C. (2023). The heat is on: Predicting urban stream temperature responses to summer storms. Hydrological Processes, 37(11), Article e15033. https://doi.org/10.1002/hyp.15033
• Hydrologic connectivity and source heterogeneity control concentration–discharge relationships
  Knapp, J. L., Li, L., & Musolff, A. (2022). Hydrologic connectivity and source heterogeneity control concentration–discharge relationships. Hydrological Processes, 36(9), Article e14683. https://doi.org/10.1002/hyp.14683
• Organizational Principles of Hyporheic Exchange Flow and Biogeochemical Cycling in River Networks Across Scales
  Krause, S., Abbott, B. W., Baranov, V., Bernal, S., Blaen, P., Datry, T., Drummond, J., Fleckenstein, J. H., Velez, J. G., Hannah, D. M., Knapp, J. L., Kurz, M., Lewandowski, J., Martí, E., Mendoza‐Lera, C., Milner, A., Packman, A., Pinay, G., Ward, A. S., & Zarnetzke, J. P. (2022). Organizational Principles of Hyporheic Exchange Flow and Biogeochemical Cycling in River Networks Across Scales. Water Resources Research, 58(3), Article e2021WR029771. https://doi.org/10.1029/2021wr029771
• Rapid Advances in Mobile Mass Spectrometry Enhance Tracer Hydrology and Water Management
  Popp, A. L., Manning, C. C., & Knapp, J. L. (2021). Rapid Advances in Mobile Mass Spectrometry Enhance Tracer Hydrology and Water Management. Water Resources Research, 57(6), Article e2021WR029890. https://doi.org/10.1029/2021wr029890
• Toward catchment hydro‐biogeochemical theories
  Li, L., Sullivan, P. L., Benettin, P., Cirpka, O. A., Bishop, K., Brantley, S. L., Knapp, J. L., Meerveld, I., Rinaldo, A., Seibert, J., Wen, H., & Kirchner, J. W. (2021). Toward catchment hydro‐biogeochemical theories. Wiley Interdisciplinary Reviews: Water, 8(1), Article e1495. https://doi.org/10.1002/wat2.1495
• Concentration–discharge relationships vary among hydrological events, reflecting differences in event characteristics
  Knapp, J. L., von Freyberg, J., Studer, B., Kiewiet, L., & Kirchner, J. W. (2020). Concentration–discharge relationships vary among hydrological events, reflecting differences in event characteristics. Hydrology and Earth System Sciences, 24(5), 2561-2576. https://doi.org/10.5194/hess-24-2561-2020
• The method controls the story - Sampling method impacts on the detection of pore-water nitrogen concentrations in streambeds
  Comer-Warner, S., Knapp, J. L., Blaen, P., Klaar, M., Shelley, F., Zarnetske, J., Lee-Cullin, J., Folegot, S., Kurz, M., Lewandowski, J., Harvey, J., Ward, A., Mendoza-Lera, C., Ullah, S., Datry, T., Kettridge, N., Gooddy, D., Drummond, J., Martí, E., Milner, A., …Krause, S. (2020). The method controls the story - Sampling method impacts on the detection of pore-water nitrogen concentrations in streambeds. Science of the Total Environment, 709, https://doi.org/10.1016/j.scitotenv.2019.136075
• Spatiotemporal Variability in Transport and Reactive Processes Across a First‐ to Fifth‐Order Fluvial Network
  Gootman, K. S., González‐Pinzón, R., Knapp, J. L., Garayburu‐Caruso, V., & Cable, J. E. (2020). Spatiotemporal Variability in Transport and Reactive Processes Across a First‐ to Fifth‐Order Fluvial Network. Water Resources Research, 56(5), https://doi.org/10.1029/2019wr026303
• Technical note: Calculation scripts for ensemble hydrograph separation
  Kirchner, J. W., & Knapp, J. L. (2020). Technical note: Calculation scripts for ensemble hydrograph separation. Hydrology and Earth System Sciences, 24(11), https://doi.org/10.5194/hess-24-5539-2020
• Technical note: Evaluation of a low-cost evaporation protection method for portable water samplers
  von Freyberg, J., Knapp, J. L., Rücker, A., Studer, B., & Kirchner, J. W. (2020). Technical note: Evaluation of a low-cost evaporation protection method for portable water samplers. Hydrology and Earth System Sciences, 24(12), 5821-5834. https://doi.org/10.5194/hess-24-5821-2020
• A Perspective on the Future of Transient Storage Modeling: Let's Stop Chasing Our Tails
  Knapp, J. L., & Kelleher, C. (2020). A Perspective on the Future of Transient Storage Modeling: Let's Stop Chasing Our Tails. Water Resources Research, 56(3), https://doi.org/10.1029/2019wr026257
• Fate of wastewater contaminants in rivers: Using conservative-tracer based transfer functions to assess reactive transport
  Guillet, G., Knapp, J. L., Merel, S., Cirpka, O. A., Grathwohl, P., Zwiener, C., & Schwientek, M. (2019). Fate of wastewater contaminants in rivers: Using conservative-tracer based transfer functions to assess reactive transport. Science of the Total Environment, 656, https://doi.org/10.1016/j.scitotenv.2018.11.379
• In-situ mass spectrometry improves the estimation of stream reaeration from gas-tracer tests
  Knapp, J. L., Osenbrück, K., Brennwald, M. S., & Cirpka, O. A. (2019). In-situ mass spectrometry improves the estimation of stream reaeration from gas-tracer tests. Science of the Total Environment, 655, https://doi.org/10.1016/j.scitotenv.2018.11.300
• Co-located contemporaneous mapping of morphological, hydrological, chemical, and biological conditions in a 5th-order mountain stream network, Oregon, USA
  Ward, A. S., Zarnetske, J. P., Baranov, V., Blaen, P. J., Brekenfeld, N., Chu, R., Derelle, R., Drummond, J., Fleckenstein, J. H., Garayburu-Caruso, V., Graham, E., Hannah, D., Harman, C. J., Herzog, S., Hixson, J., Knapp, J. L., Krause, S., Kurz, M. J., Lewandowski, J., Li, A., …Wondzell, S. M. (2019). Co-located contemporaneous mapping of morphological, hydrological, chemical, and biological conditions in a 5th-order mountain stream network, Oregon, USA. Earth System Science Data, 11(4), https://doi.org/10.5194/essd-11-1567-2019
• Exploring Tracer Information and Model Framework Trade‐Offs to Improve Estimation of Stream Transient Storage Processes
  Kelleher, C., Ward, A., Knapp, J., Blaen, P., Kurz, M., Drummond, J., Zarnetske, J., Hannah, D., Mendoza‐Lera, C., Schmadel, N., Datry, T., Lewandowski, J., Milner, A., & Krause, S. (2019). Exploring Tracer Information and Model Framework Trade‐Offs to Improve Estimation of Stream Transient Storage Processes. Water Resources Research, 55(4), https://doi.org/10.1029/2018wr023585
• New water fractions and transit time distributions at Plynlimon, Wales, estimated from stable water isotopes in precipitation and streamflow
  Knapp, J. L., Neal, C., Schlumpf, A., Neal, M., & Kirchner, J. W. (2019). New water fractions and transit time distributions at Plynlimon, Wales, estimated from stable water isotopes in precipitation and streamflow. Hydrology and Earth System Sciences, 23(10), https://doi.org/10.5194/hess-23-4367-2019
• Spatial and temporal variation in river corridor exchange across a 5th-order mountain stream network
  Ward, A. S., Wondzell, S. M., Schmadel, N. M., Herzog, S., Zarnetske, J. P., Baranov, V., Blaen, P. J., Brekenfeld, N., Chu, R., Derelle, R., Drummond, J., Fleckenstein, J. H., Garayburu-Caruso, V., Graham, E., Hannah, D., Harman, C. J., Hixson, J., Knapp, J. L., Krause, S., Kurz, M. J., …Wisnoski, N. I. (2019). Spatial and temporal variation in river corridor exchange across a 5th-order mountain stream network. Hydrology and Earth System Sciences, 23(12), https://doi.org/10.5194/hess-23-5199-2019
• Solute Transport and Transformation in an Intermittent, Headwater Mountain Stream with Diurnal Discharge Fluctuations
  Ward, A. S., Kurz, M. J., Schmadel, N. M., Knapp, J. L., Blaen, P. J., Harman, C. J., Drummond, J. D., Hannah, D. M., Krause, S., Li, A., Marti, E., Milner, A., Miller, M., Neil, K., Plont, S., Packman, A. I., Wisnoski, N. I., Wondzell, S. M., & Zarnetske, J. P. (2019). Solute Transport and Transformation in an Intermittent, Headwater Mountain Stream with Diurnal Discharge Fluctuations. Water, 11(11), Article 2208. https://doi.org/10.3390/w11112208
• The Resazurin-Resorufin System: Insights From a Decade of “Smart” Tracer Development for Hydrologic Applications
  Knapp, J. L., González-Pinzón, R., & Haggerty, R. (2018). The Resazurin-Resorufin System: Insights From a Decade of “Smart” Tracer Development for Hydrologic Applications. Water Resources Research, 54(9), https://doi.org/10.1029/2018wr023103
• A Critical Assessment of Relating Resazurin–Resorufin Experiments to Reach‐Scale Metabolism in Lowland Streams
  Knapp, J. L., & Cirpka, O. A. (2018). A Critical Assessment of Relating Resazurin–Resorufin Experiments to Reach‐Scale Metabolism in Lowland Streams. Journal of Geophysical Research: Biogeosciences, 123(12), https://doi.org/10.1029/2018jg004797
• Woody debris is related to reach-scale hotspots of lowland stream ecosystem respiration under baseflow conditions
  Blaen, P., Kurz, M., Drummond, J., Knapp, J., Mendoza-Lera, C., Schmadel, N., Klaar, M., Jäger, A., Folegot, S., Lee-Cullin, J., Ward, A., Zarnetske, J., Datry, T., Milner, A., Lewandowski, J., Hannah, D., & Krause, S. (2018). Woody debris is related to reach-scale hotspots of lowland stream ecosystem respiration under baseflow conditions. Ecohydrology, 11(5), https://doi.org/10.1002/eco.1952
• Tracer‐based characterization of hyporheic exchange and benthic biolayers in streams
  Knapp, J. L., González‐Pinzón, R., Drummond, J. D., Larsen, L. G., Cirpka, O. A., & Harvey, J. W. (2017). Tracer‐based characterization of hyporheic exchange and benthic biolayers in streams. Water Resources Research, 53(2), https://doi.org/10.1002/2016wr019393
• Determination of hyporheic travel time distributions and other parameters from concurrent conservative and reactive tracer tests by local‐in‐global optimization
  Knapp, J. L., & Cirpka, O. A. (2017). Determination of hyporheic travel time distributions and other parameters from concurrent conservative and reactive tracer tests by local‐in‐global optimization. Water Resources Research, 53(6), https://doi.org/10.1002/2017wr020734
• Stream solute tracer timescales changing with discharge and reach length confound process interpretation
  Schmadel, N. M., Ward, A. S., Kurz, M. J., Fleckenstein, J. H., Zarnetske, J. P., Hannah, D. M., Blume, T., Vieweg, M., Blaen, P. J., Schmidt, C., Knapp, J. L., Klaar, M. J., Romeijn, P., Datry, T., Keller, T., Folegot, S., Arricibita, A. I. M., & Krause, S. (2016). Stream solute tracer timescales changing with discharge and reach length confound process interpretation. Water Resources Research, 52(4), https://doi.org/10.1002/2015wr018062
• Impact of non-idealities in gas-tracer tests on the estimation of reaeration, respiration, and photosynthesis rates in streams
  Knapp, J. L., Osenbrück, K., & Cirpka, O. A. (2015). Impact of non-idealities in gas-tracer tests on the estimation of reaeration, respiration, and photosynthesis rates in streams. Water Research, 83, https://doi.org/10.1016/j.watres.2015.06.032