Highlighted Publications

Leveraging structural differences in modelling approaches to learn about hydrologic drivers
The representations we use when analyzing data and modeling systems completely determine the questions we can ask. Any modeling approach may be highly suitable for learning certain things about a system but completely unsuitable for others. We explore how three different modeling approaches (one lumped water balance method and two machine learning methods) can improve understanding of catchment-scale hydrological processes across Chile.

Projecting Warming induced groundwater losses across the US
Using a high-resolution groundwater surface water model for the US we quantify the groundwater losses caused by increased plant water use in a warmer future. Warming results in increased aridification in North America and reduced groundwater surface water connections. When shallow groundwater is present it can buffer plant water stress but not indefinitely. Once this storage is depleted it does not easily recover. In the western US where groundwater is already deeper, there is a weaker connection between warming and storage loss.

Where is the bottom of a watershed?
Turns out it depends who you ask! There is great variability across the earth science community in their treatment of the subsurface both in how they handle the lower boundary condition and where they place it. This commentary explores approaches across our communities and outlines a path forward.
Complete Publication List Peer Reviewed Publications
- Condon, LE, A Farley, S Jourdain, P O’leary, P Avery, L Gallagher, C Chennault, RM Maxwell (2023). ParFlow Sand Tank: A tool for groundwater exploration. Journal of Open Source Education. 6(61), 179.
- De la Fuente, L, HV Gupta, LE Condon (2023) Toward a Multi-Representational Approach to Prediction and Understanding, in Support of Discovery in Hydrology. Water Resources Research. 59 (1).
- Gallagher, LK, AJ Farley, C Chennault, S Cerasoli, S Jourdain, P O’Leary, LE Condon & RM Maxwell (2022). The ParFlow Sandtank: An Interactive education tool making invisible groundwater visible. Frontiers in Water. 4.
- Baru C, Pozmantier M, Altintas I, LE Condon et al (2022). Enabling AI innovation via data and model sharing: An overview of the NSF Convergence Accelerator Track D. AI Magazine. 43(1):93-104.
- Steyaert, JC, LE Condon, S Turner, N Voisin (2022). ResOpsUS, A dataset of historical reservoir operations in the contiguous United States. Sci Data, 9(34). Highlights…
- Maxwell, RM, LE Condon, and P Melchior (2021). A Physics-Informed, Machine Learning Emulator of a 2D Surface Water Model: What Temporal Networks and Simulation-Based Inference Can Help Us Learn about Hydrologic Processes. Water, 13, no. 24.
- Condon, LE, S Kollet, MFP Bierkens, GE Fogg, RM Maxwell, MC Hill, HH Fransen, et al (2021). Global Groundwater Modeling and Monitoring: Opportunities and Challenges. Water Resources Research 57, no. 12: e2020WR029500.
- Gallagher, LK, JM Williams, D Lazzeri, C Chennault, S Jourdain, P O’Leary, LE Condon, and RM Maxwell (2021). Sandtank-ML: An Educational Tool at the Interface of Hydrology and Machine Learning. Water 13, no. 23.
- O’Neill, MMF, DT Tijerina, LE Condon, and RM Maxwell (2021). Assessment of the ParFlow–CLM CONUS 1.0 Integrated Hydrologic Model: Evaluation of Hyper-Resolution Water Balance Components across the Contiguous United States. Geoscientific Model Development 14, no. 12: 7223–54.
- Tran, H, E Leonarduzzi, L De la Fuente, RB Hull, V Bansal, C Chennault, P Gentine, P Melchior, LE Condon, and RM Maxwell (2021). Development of a Deep Learning Emulator for a Distributed Groundwater–Surface Water Model: ParFlow-ML. Water 13, no. 23.
- Turner, SWD, JC Steyaert, LE Condon, and N Voisin (2021). Water Storage and Release Policies for All Large Reservoirs of Conterminous United States. Journal of Hydrology 603: 126843.
- Gleeson T, T Wagener, P Döll, SC Zipper, C West, Y Wada, R Taylor, B Scanlon, R Rosolem, S Rahman, N Oshinlaja, R Maxwell, MH Lo, H Kim, M Hill, A Hartmann, G Fogg, JS Famiglietti, A Ducharne, I de Graaf, M Cuthbert, LE Condon, E Bresciani, MFP Bierkens,(2021) GMD Perspective: The Quest to Improve the Evaluation of Groundwater Representation in Continental to Global Scale Models. Geosci. Model Dev. Discuss. 1–59.
- Zhang, J, LE Condon, H Tran and RM Maxwell (2021). A National topographic dataset for hydrological modeling over the contiguous United States, Earth System Science data, Earth Syst. Sci. Data, 13, 3263–3279.
- Tijerina, D, LE Condon, K FitzGerald, A Dugger, MM O’Neil, K Sampson, D Gochis and RM Maxwell (2021), Continental Hydrologic Intercomparison Project, Phase 1: A Large-Scale Hydrologic Model Comparison Over the Continental United States. Water Resources Research, 57, e2020WR028931
- Markovich, KH, LE Condon, KC Carroll R Purtschert, and JC McIntosh (2021). A mountain-front recharge component characterization approach combining groundwater age distributions, noble gas thermometry, and fluid and energy transport modeling, Water Resources Research 57, e2020WR027743
- Rapp, G, LE Condon, KH Markovich (2020). Sensitivity of Simulated Mountain-Block Hydrology to Subsurface Conceptualization, Water Resources Research, 56, e2020WR027714.
- DeGraaf, I, LE Condon and RM Maxwell (2020). Hyper-resolution continental-scale 3D-aquifer parameterization for groundwater modelling, Water Resources Research,56, e2019WR026004, https://doi.org/10.1029/2019WR026004.
- Tran, H, J Zhang, JM Cohard, LE Condon and RM Maxwell (2020). Simulating groundwater-streamflow connections in the Upper Colorado River Basin, Groundwater, 58:392-405.
- Fayaz, N, LE Condon and DG Chandler (2020). Evaluating the sensitivity of projected reservoir reliability to the choice of climate projection: A case study of Bull Run Watershed, Portland, Oregon, Water resources Management, https://doi.org/10.1007/s11269-020-02542-3.
- Kuffour, BNO, NB Engdahl, CS Woodward, LE Condon, S Kollet, and RM Maxwell (2020). Simulating coupled surface–subsurface flows with ParFlow v3.5.0: capabilities, applications, and ongoing development of an open-source, massively parallel, integrated hydrologic model. Geosci. Model Dev., 13(3), 1373-1397.
- Condon, LE, KH Markovich, CA Kelleher, JJ McDonnell, G Ferguson and JC McIntosh (2020). Where is the bottom of a watershed? Water Resources Research, 56, e2019WR026010, https://doi.org/10.1029/2019WR026010.
- Van Dusen, P, B Rajagopalan, DJ Lawrence, LE Condon, G Smilie, S Gangopadhyay and T Pruitt (2020). 21st Century Flood Risk Projections and Selected Sites for the U.S. National Parks Service, Climate Risk Management, 28,100211.
- Condon, LE, AL Atchley and RM Maxwell (2020). Evapotranspiration depletes groundwater under warming over the contiguous United States. Nature Communications, 11(873).
- Markovich, KH, AH Manning, LE Condon, JC McIntosh (2019). Mountain-block Recharge: A Review of Current Understanding. Water Resources Research, 55, https://doi.org/10.1029/2019WR025676.
- Condon, LE and RM Maxwell (2019). Simulating the sensitivity of evapotranspiration and streamflow to large-scale groundwater depletion. Science Advances 5(6): eaav4574. https://doi.org/10.1126/sciadv.aav4574
- Hein, A, LE Condon and RM Maxwell (2019). Evaluating the relative importance of precipitation, temperature and land-cover change in the hydrologic response to extreme meteorological drought conditions over the North American High Plains. Hydrol. Earth Syst. Sci, https://doi.org/10.5194/hess-23-1931-2019.
- Condon, LE and RM Maxwell (2019). Modified priority flood and global slope enforcement algorithm for topographic processing in physically based hydrologic modeling applications. Computers & Geosciences, https://doi.org/10.1016/j.cageo.2019.01.020.
- Ehmann, K, C Kelleher, LE Condon (2018). Monitoring turbidity from above: Deploying small unoccupied aerial vehicles to image in-stream turbidity. Hydrological Processes https://doi.org/10.1002/hyp.13372.
- Maxwell, RM, LE Condon, M Danesh-Yazdi, and LA Bearup (2018).Exploring source water mixing and transient residence time distributions of outflow and evapotranspiration with an integrated hydrologic model and Lagrangian particle tracking approach. Ecohydrology, 2018;e2042, doi:10.1002/eco.2042, 2018.
- Kelleher, C, CA Scholz, LE Condon, and M Reardon (2018), Drones in geoscience research: The sky is the only limit, Eos, 99, https://doi.org/10.1029/2018EO092269.
- Danesh-Yazdi, M., J Klaus, LE Condon and RM Maxwell (2018). Bridging the gap between numerical solutions of travel time distributions and analytical storage selection functions. 32(8): p. 1063-1076, doi:10.1002/hyp.11481
- Condon, LE and RM Maxwell (2017). Systematic shifts in Budyko relationships caused by groundwater storage changes. Hydrol. Earth Syst. Sci., 21(2): p. 1117-1135, doi:10.5194/hess-21-1117-2017
- Maxwell, RM and LE Condon (2016). Connections between groundwater flow and transpiration partitioning. Science, 353:6297, 377-380 doi:10.1126/science.aaf7891.
- Maxwell, RM, LE Condon, SJ Kollet, K Maher, R Haggerty, and MM Forrester (2016). The imprint of climate and geology on the residence times of groundwater. Geophysical Research Letters, 43:2, 701-708, doi:10.1002/2015GL066916
- Condon, LE and RM Maxwell (2015). Evaluating the relationship between topography and groundwater using outputs from a continental-scale integrated hydrology model. Water Resources Research, doi:10.1002/2014WR016774
- Condon, LE, AS Hering, and RM Maxwell (2015). Quantitative assessment of groundwater controls across major US river basins using a multi-model regression algorithm. Advances in Water Resources, 82, 106-123. doi:10.1016/j.advwatres.2015.04.008
- Maxwell, RM, LE Condon, and SJ Kollet (2015). A high resolution simulation of groundwater and surface water over most of the continental US with the integrated hydrologic model ParFlow v3. Geoscientific Model Development, 8, 923-937. doi:10.5194/gmd-8-1-2015
- Bierkens, MFP, V Bell, P Burek, N Chaney, LE Condon, C David, A de Roo, P Doell, N Drost, J Famiglietti, M Florke, D Gochis, P Houser, R Hut, J Keune, S Kollet, RM Maxwell, J Reager, L Samaniego, E Sutandudjaja, N van de Giesen, H Winsemius, E Wood (2015). Hyper-resolution global hydrological modelling: what’s next? Hydrologic Processes, 29(2), 310-320. doi:10.1002/hyp.10391
- Condon, LE, S Gangopadhyay, and T Pruitt (2015). Climate change and non-stationary flood risk for the Upper Truckee River Basin. Hydrol. Earth Syst., 19(1), 159-175. doi: 10.5194/hess-19-159-2015
- Condon, LE and RM Maxwell (2014). Feedbacks between managed irrigation and water availability: Diagnosing temporal and spatial patterns using an integrated hydrologic model. Water Resources Research, 50(3), 2600-2616. doi:10.1002/2013WR014868
- Condon, LE and RM Maxwell (2014). Groundwater-fed irrigation impacts spatially distributed temporal scaling behavior of the natural system: A spatio-temporal framework for understanding water management impacts. Environmental Research Letters, 9(3), 034009. doi:10.1088/1748-9326/9/3/034009
- Condon, LE and RM Maxwell (2013). Implementation of a linear optimization water allocation algorithm into a fully integrated physical hydrology model. Advances in Water Resources, 60, 135-147. doi:10.1016/j.advwatres.2013.07.012
- Condon, LE, RM Maxwell, and S Gangopadhyay (2013). The impact of subsurface conceptualization on land energy fluxes. Advances in Water Resources, 60, 188-203. doi:10.1016/j.advwatres.2013.08.001
- Gong, G, L Wang, LE Condon, A Shearman, and U Lall (2010). A Simple Framework for Incorporating Seasonal Streamflow Forecasts into Existing Water Resources Management Practices. JAWRA, 46(3), 574-585. doi:10.1111/j.1752-1688.2010.00435.x
Technical Reports
- Maxwell, RM, SJ Kollet, SG Smith, CS Woodward, RD Falgout, IM Ferguson, N Engdahl, LE Condon, S Lopez, J Gilbert, L Bearup, J Jefferson, C Prubilick, C Baldwin, WJ Bosl, R Hornung, and S Ashby (2014). ParFlow User’s Manual, International Ground Water Modeling Center, GMWI 2014-01 v.693.
- Condon, LE, K Blickenstaff, and S Gangopadhyay (2013). Mojave River Watershed Climate Change Assessment. US Department of the interior, Bureau of Reclamation, Technical Memorandum No. 86-68210-2013-04.
- Blickenstaff, K, SG Gangopadhyay, I Ferguson, LE Condon, and T Pruitt (2013). Climate Change Analysis for the Santa Ana River Watershed. US Department of the Interior, Bureau of Reclamation, Technical Memorandum No. 86-68210-2013-02.