Staff information

Biography

Dr. Xingyuan Chen is an earth scientist with extensive research experience in groundwater flow and transport modeling, stochastic inverse modeling, data assimilation, geostatistics, and ecohydrology. Since joining PNNL in 2010, Dr. Chen has applied various Bayesian data assimilation techniques to characterize the heterogeneous aquifer properties of the Hanford 300 Area by integrating multi-scale and multi-type lab and field experimental data available at the site. In her research, Dr. Chen has leveraged high performance computing resources, e.g., community flow and transport code PFLOTRAN and the supercomputers at the National Energy Research Scientific Computing Center (NERSC) and Oak Ridge Leadership Computing Facility (OLCF), to enable increasingly mechanistic non-linear forward simulations for a complex system within the stochastic data assimilation framework.

Research Interests

• Uncertainty quantification and data assimilation
• Subsurface flow and transport modeling
• Watershed hydrologic and biogeochemical modeling
• Spatial-temporal data analysis using machine learning
• Ecohydrology

Education and Credentials

• Ph.D., Civil and Environmental Engineering, University of California at Berkeley, 2009
• M.A., Statistics, University of California at Berkeley, 2007
• M.Phil., Civil Engineering, Hong Kong University of Science and Technology, 2002
• B.E., Hydraulic Engineering, Tsinghua University, Beijing, 2000

Affiliations and Professional Service

• Member of American Geophysical Union (AGU)

PNNL Publications

2024

• Gonzalez-Duque D., J.D. Gomez-Velez, J.P. Zarnetske, X. Chen, and T.D. Scheibe. 2024. "Sinuosity-driven Hyporheic Exchange: Hydrodynamics and Biogeochemical Potentials." Water Resources Research 60, no. 4:Art. No. e2023WR036023. PNNL-SA-187573. doi:10.1029/2023WR036023
• Patel K.F., K.A. Rod, J. Zheng, P.J. Regier, F. Machado-Silva, B. Bond-Lamberty, and X. Chen, et al. 2024. "Time to anoxia: Observations and predictions of oxygen drawdown following coastal flood events." Geoderma 444. PNNL-SA-190684. doi:10.1016/j.geoderma.2024.116854
• Zhou Y., P. Jiang, P. Chen, E. Jia, C.S. Welch, Q. Zhao, and J.A. Dhas, et al. 2024. "Novel Principal Component Analysis Tool based on Python for Analysis of Complex Spectra of Time-of-Flight Secondary Ion Mass Spectrometry." Journal of Vacuum Science & Technology A: International Journal Devoted to Vacuum, Surfaces, and Films A42, no. 2:Art. No. 023204. PNNL-SA-189615. doi:10.1116/6.0003355

2023

• Adebayo M.B., V.L. Bailey, X. Chen, A.M. Hopple, P. Jiang, B. Li, and Z. Li, et al. 2023. "A hydrogeophysical framework to assess infiltration during a simulated ecosystem-scale flooding experiment." Journal of Hydrology 626, no. Part A:Art. No. 130243. PNNL-SA-185996. doi:10.1016/j.jhydrol.2023.130243
• Chen K., S. Yang, E.E. Roden, X. Chen, K. Chang, Z. Guo, and X. Liang, et al. 2023. "Influence of Vertical Hydrologic Exchange Flow, Channel Flow, and Biogeochemical Kinetics on CH4 Emissions From Rivers." Water Resources Research 59, no. 12:Art. No. e2023WR035341. PNNL-SA-193786. doi:10.1029/2023WR035341
• Chen K., X. Chen, J.C. Stegen, J.A. Villa, G. Bohrer, X. Song, and K. Chang, et al. 2023. "Vertical hydrologic exchange flows control methane emissions from riverbed sediments." Environmental Science & Technology 57, no. 9:4014-4026. PNNL-SA-178729. doi:10.1021/acs.est.2c07676
• Chen X., D. Dwivedi, and H.A. Michael. 2023. "Editorial: Hydrology, Ecology, and Nutrient Biogeochemistry at the Terrestrial-Aquatic Interface." Frontiers in Environmental Science 11. PNNL-SA-191450. doi:10.3389/fenvs.2023.1322708
• Jiang P., P. Shuai, A. Sun, M. Mudunuru, and X. Chen. 2023. "Knowledge-Informed Deep Learning for Hydrological Model Calibration: An Application to Coal Creek Watershed in Colorado." Hydrology and Earth System Sciences 27, no. 14:2621-2644. PNNL-SA-175917. doi:10.5194/hess-27-2621-2023
• Jiang P., Z. Yang, J. Wang, C. Huang, P. Xue, T. Chakraborty, and X. Chen, et al. 2023. "Efficient Super-Resolution of Near-Surface Climate Modeling Using the Fourier Neural Operator." Journal of Advances in Modeling Earth Systems 15, no. 7:Art. No. e2023MS003800. PNNL-SA-186550. doi:10.1029/2023MS003800
• McDowell N.G., K.J. Anderson-Teixeira, J.A. Biederman, D.D. Breshears, Y. Fang, L. Fernandez De Una, and E.B. Graham, et al. 2023. "Ecohydrological Decoupling under Changing Disturbances and Climate." One Earth 6, no. 3:251-266. PNNL-SA-189590. doi:10.1016/j.oneear.2023.02.007
• Perez Mesa G., J.D. Gomez Velez, X. Chen, and T.D. Scheibe. 2023. "The Directional Unit Hydrograph Method: Connecting Streamflow Response to Storm Dynamics." Journal of Hydrology 627, no. Part A:130422. PNNL-SA-178480. doi:10.1016/j.jhydrol.2023.130422
• Shuai P., P. Jiang, E. Coon, and X. Chen. 2023. "The importance of explicitly representing the streambed in watershed models." Hydrological Processes 37, no. 12:Art. No. e15043. PNNL-SA-184264. doi:10.1002/hyp.15043
• Xiao Y., J.M. Sloan, C. Hepworth, M. Fradera-Soler, A. Mathers, R. Thorley, and A. Baillie, et al. 2023. "Defining the scope for altering rice leaf anatomy to improve photosynthesis: A modelling approach." New Phytologist 237, no. 2:441-453. PNNL-SA-177158. doi:10.1111/nph.18564

2022

• Chen K., X. Chen, X. Song, M. Briggs, P. Jiang, P. Shuai, and G.E. Hammond, et al. 2022. "Using Ensemble Data Assimilation to Estimate Transient Hydrologic Exchange Flow under Highly Dynamic Flow Conditions." Water Resources Research 58, no. 5:Art. No. e2021WR030735. PNNL-SA-165451. doi:10.1029/2021WR030735
• Dwivedi D., C.I. Steefel, B. Arora, J.F. Banfield, J.R. Bargar, J.R. Bargar, and M.I. Boyanov, et al. 2022. "From Legacy Contamination to Watershed Systems Science: A Review of Scientific Insights and Technologies Developed through DOE-Supported Research in Water and Energy Security." Environmental Research Letters 17, no. 4:Art. No. 043004. PNNL-SA-161347. doi:10.1088/1748-9326/ac59a9
• Jiang P., X. Chen, J.E. Missik, Z. Gao, H. Liu, and B.A. Verbeke. 2022. "Encoding Diel Hysteresis and the Birch Effect in Dryland Soil Respiration Models through Knowledge-Guided Deep Learning." Frontiers in Environmental Science 10. PNNL-SA-179483. doi:10.3389/fenvs.2022.1035540
• Mudunuru M., E. Cromwell, H. Wang, and X. Chen. 2022. "Deep Learning to Estimate Permeability using Geophysical Data." Advances in Water Resources 167. PNNL-SA-175440. doi:10.1016/j.advwatres.2022.104272
• Mudunuru M., K. Son, P. Jiang, G.E. Hammond, and X. Chen. 2022. "Scalable Deep Learning for Watershed Model Calibration." Frontiers in Earth Science 10. PNNL-SA-176859. doi:10.3389/feart.2022.1026479
• Ren H., E. Cromwell, B.S. Kravitz, and X. Chen. 2022. "Technical note: Using Long Short-term Memory Models to Fill Data Gaps in Hydrological Monitoring Networks." Hydrology and Earth System Sciences 26, no. 7:1727-1743. PNNL-SA-161724. doi:10.5194/hess-26-1727-2022
• Shuai P., X. Chen, U. Mital, E. Coon, and D. Dwivedi. 2022. "The Effects of Spatial and Temporal Resolution of Gridded Meteorological Forcing on Watershed Hydrological Responses." Hydrology and Earth System Sciences 26, no. 8:2245-2276. PNNL-SA-167101. doi:10.5194/hess-26-2245-2022
• Son K., Y. Fang, J.D. Gomez Velez, and X. Chen. 2022. "Spatial microbial respiration variations in the hyporheic zones within the Columbia River Basin." Journal of Geophysical Research: Biogeosciences 127, no. 11:Art. No. e2021JG006654. PNNL-SA-178479. doi:10.1029/2021JG006654
• Son K., Y. Fang, J.D. Gomez Velez, K. Byun, and X. Chen. 2022. "Combined effects of stream hydrology and land use on basin-scale hyporheic zone denitrification in the Columbia River Basin." Water Resources Research 58, no. 12:Art. No. e2021WR031131. PNNL-SA-165887. doi:10.1029/2021WR031131
• Sun A., P. Jiang, Z. Yang, Y. Xie, and X. Chen. 2022. "A graph neural network (GNN) approach to basin-scale river network learning: The role of physics-based connectivity and data fusion." Hydrology and Earth System Sciences 26, no. 19:5163-5184. PNNL-SA-177141. doi:10.5194/hess-26-5163-2022
• Yao J., W. Yuan, Z. Gao, H. Liu, X. Chen, Y. Ma, and E.V. Arntzen, et al. 2022. "Impact of shifts in vegetation phenology on the carbon balance of a semiarid sagebrush ecosystem." Remote Sensing 14, no. 23:Art. No. 5924. PNNL-SA-179255. doi:10.3390/rs14235924

2021

• Chen X., R.M. Lee, D. Dwivedi, K. Son, Y. Fang, X. Zhang, and E.B. Graham, et al. "Integrating Field Observations and Reactive Transport Modeling to Predict Watershed Water Quality under Environmental Perturbations."
• Chen X., R.M. Lee, D. Dwivedi, K. Son, Y. Fang, X. Zhang, and E.B. Graham, et al. 2021. "Integrating Field Observations and Process-based Modeling to Predict Watershed Water Quality under Environmental Perturbations." Journal of Hydrology 602. PNNL-SA-148272. doi:10.1016/j.jhydrol.2020.125762
• Chu H., X.R. Luo, Z. Ouyang, W.S. Chan, S. Dengel, S. Biraud, and M.S. Torn, et al. 2021. "Representativeness of Eddy-Covariance flux footprints for areas surrounding AmeriFlux sites." Agricultural and Forest Meteorology 301. PNNL-SA-157254. doi:10.1016/j.agrformet.2021.108350
• Conner A., M. Gooseff, X. Chen, E.V. Arntzen, and V.A. Garayburu-Caruso. 2021. "Groundwater Inflows to the Columbia River Along the Hanford Reach and Associated Nitrate Concentrations." Frontiers in Water 3. PNNL-SA-161403. doi:10.3389/frwa.2021.574684
• Cromwell E., P. Shuai, P. Jiang, E. Coon, S.L. Painter, D. Moulton, and Y. Lin, et al. 2021. "Estimating Watershed Subsurface Permeability From Stream Discharge Data using Deep Neural Networks." Frontiers in Earth Science 9. PNNL-SA-156876. doi:10.3389/feart.2021.613011
• Hou Z., H. Ren, C.J. Murray, X. Song, Y. Fang, E.V. Arntzen, and X. Chen, et al. 2021. "A Novel Construct for Scaling Groundwater-River Interactions Based on Machine-Guided Hydromorphic Classification." Environmental Research Letters 16, no. 10:104016. PNNL-SA-151112. doi:10.1088/1748-9326/ac24ce
• Jiang P., X. Chen, K. Chen, J. Anderson, N. Collins, and M. Gharamti. 2021. "DART-PFLOTRAN: An Ensemble-based Data Assimilation System for Estimating Subsurface Flow and Transport Model Parameters." Environmental Modelling & Software 142. PNNL-SA-160802. doi:10.1016/j.envsoft.2021.105074
• Missik J.E., H. Liu, Z. Gao, M. Huang, X. Chen, E.V. Arntzen, and D.P. McFarland, et al. 2021. "Groundwater regulates interannual variations in evapotranspiration in a riparian semiarid ecosystem." Journal of Geophysical Research: Atmospheres 126, no. 7:Article No. e2020JD033078. PNNL-SA-153611. doi:10.1029/2020jd033078
• Moghaddam M., T.P. Ferre, X. Chen, K. Chen, X. Song, and G. Hammond. 2021. "Can Simple Machine Learning Tools Extend and Improve Temperature-Based Methods to Infer Streambed Flux?." Water 13, no. 20:Art. No. 2837. PNNL-SA-151168. doi:10.3390/w13202837
• Wu R., X. Chen, G.E. Hammond, G. Bisht, X. Song, M. Huang, and G. Niu, et al. 2021. "Coupling Surface Flow with High-performance Subsurface Reactive Flow and Transport Code PFLOTRAN." Environmental Modelling & Software 137. PNNL-SA-156109. doi:10.1016/j.envsoft.2021.104959
• Xiao Y., J.M. Sloan, C. Hepworth, C.P. Osborne, A.J. Flemming, X. Chen, and X. Zhu. 2021. "Estimating uncertainty: A Bayesian approach to modelling photosynthesis in C3 leaves." Plant, Cell & Environment 44, no. 5:1436-1450. PNNL-SA-161702. doi:10.1111/pce.13995
• Zhang Y., D. Zhou, W. Wei, J.M. Frame, H. Sun, A. Sun, and X. Chen. 2021. "Hierarchical Fractional Advection-Dispersion Equation (FADE) to Quantify Anomalous Transport in River Corridor over a Broad Spectrum of Scales: Theory and Applications." Mathematics 9, no. 7:790. PNNL-SA-160334. doi:10.3390/math9070790
• Zhu B., M. Huang, Y. Cheng, X. Xie, Y. Liu, G. Bisht, and X. Chen. 2021. "Impact of vegetation physiology and phenology on watershed hydrology in a semiarid watershed in the Pacific Northwest in a changing climate." Water Resources Research 57, no. 3:e2020WR028394. PNNL-SA-154491. doi:10.1029/2020WR028394

2020

• Chen X., J.M. Zachara, V.R. Vermeul, G. Hammond, M.D. Freshley, and Y. Fang. 2020. "Understanding Contaminant Migration within a Dynamic River Corridor through Field Experiments and Reactive Transport Modeling." Frontiers in Water 2. PNNL-SA-151389. doi:10.3389/frwa.2020.533796
• Fang Y., X. Chen, J.D. Gomez Velez, X. Zhang, Z. Duan, G. Hammond, and A.E. Goldman, et al. 2020. "A multirate mass transfer model to represent the interaction of multicomponent biogeochemical processes between surface water and hyporheic zones (SWAT-MRMT-R 1.0)." Geoscientific Model Development 13, no. 8:3553-3569. PNNL-SA-148784. doi:10.5194/gmd-13-3553-2020
• Fang Y., X. Song, H. Ren, W.A. Perkins, P. Shuai, M.C. Richmond, and Z. Hou, et al. 2020. "High-performance simulation of dynamic hydrologic exchange and implications for surrogate flow and reactive transport modeling in a large river corridor." Frontiers in Water 2. PNNL-SA-153319. doi:10.3389/frwa.2020.564211
• Gao Z., H. Liu, E.V. Arntzen, D.P. McFarland, X. Chen, and M. Huang. 2020. "Uncertainties in turbulent statistics and fluxes of CO2 associated with density effect corrections." Geophysical Research Letters 47, no. 15:Article No. e2020GL088859. PNNL-SA-153577. doi:10.1029/2020GL088859
• Gao Z., H. Liu, X. Chen, M. Huang, J.E. Missik, J. Yao, and E.V. Arntzen, et al. 2020. "Enlarged Nonclosure of Surface Energy Balance With Increasing Atmospheric Instabilities Linked to Changes in Coherent Structures." Journal of Geophysical Research: Atmospheres 125, no. 14:Article No. e2020JD032889. PNNL-SA-151292. doi:10.1029/2020JD032889
• Li B., X. Liu, M.H. Kaufman, A. Turetcaia, X. Chen, and M.B. Cardenas. 2020. "Flexible and Modular Simultaneous Modeling of Flow and Reactive Transport in Rivers and Hyporheic Zones." Water Resources Research 56, no. 2:e2019WR026528. PNNL-SA-153132. doi:10.1029/2019WR026528
• Rizzo C., X. Song, F. De Barros, and X. Chen. 2020. "Temporal flow variations interact with spatial physical heterogeneity to impact solute transport in managed river corridors." Journal of Contaminant Hydrology 235. PNNL-SA-153233. doi:10.1016/j.jconhyd.2020.103713
• Song H., J.C. Stegen, E.B. Graham, J. Lee, V.A. Garayburu-Caruso, W.C. Nelson, and X. Chen, et al. 2020. "Representing Organic Matter Thermodynamics in Biogeochemical Reactions via Substrate-Explicit Modeling." Frontiers in Microbiology 11. PNNL-SA-151734. doi:10.3389/fmicb.2020.531756
• Song X., X. Chen, J.M. Zachara, J. Gomez-Velez, P. Shuai, H. Ren, and G.E. Hammond. 2020. "River Dynamics Control Transit Time Distributions and Biogeochemical Reactions in a Dam-Regulated River Corridor." Water Resources Research 56, no. 9:Article No. e2019WR026470. PNNL-SA-146640. doi:10.1029/2019WR026470
• Tso C., T.C. Johnson, X. Song, X. Chen, O. Kuras, P. Wilkinson, and S. Uhlemann, et al. 2020. "Integrated hydrogeophysical modelling and data assimilation for geoelectrical leak detection." Journal of Contaminant Hydrology 234. PNNL-SA-152552. doi:10.1016/j.jconhyd.2020.103679
• Villa J.A., G. Smith, Y. Ju, L. Renteria, J.C. Angle, E.V. Arntzen, and S.F. Harding, et al. 2020. "Methane and nitrous oxide porewater concentrations and surface fluxes of a regulated river." Science of the Total Environment 715. PNNL-SA-149661. doi:10.1016/j.scitotenv.2020.136920
• Yabusaki S.B., A.N. Myers-Pigg, N.D. Ward, S.R. Waichler, A. Sengupta, Z. Hou, and X. Chen, et al. 2020. "Floodplain inundation and salinization from a recently restored first-order tidal stream." Water Resources Research 56, no. 7:Article No. e2019WR026850. PNNL-SA-149723. doi:10.1029/2019WR026850
• Yao J., H. Liu, J. Huang, Z. Gao, G. Wang, D. Li, and H. Yu, et al. 2020. "Accelerated dryland expansion regulates future variability in dryland gross primary production." Nature Communications 11, no. 1:1665. PNNL-SA-151970. doi:10.1038/s41467-020-15515-2
• Zachara J.M., X. Chen, X. Song, P. Shuai, C.J. Murray, and C.T. Resch. 2020. "Kilometer-scale hydrologic exchange flows in a gravel bed river corridor and their implications to solute migration." Water Resources Research 56, no. 2:Article NO. e2019WR025258. PNNL-SA-137616. doi:10.1029/2019WR025258
• Zhu B., M. Huang, Y. Cheng, X. Xie, Y. Liu, X. Zhang, and G. Bisht, et al. 2020. "Effects of irrigation on water, carbon, and nitrogen budgets in a semi-arid watershed in the Pacific Northwest: A modelling study." Journal of Advances in Modeling Earth Systems 12, no. 9:Article No. e2019MS001953. PNNL-SA-149346. doi:10.1029/2019MS001953

2019

• Dai H., M. Ye, B.X. Hu, A.W. Niedoroda, X. Zhang, X. Chen, and X. Song, et al. 2019. "Hierarchical sensitivity analysis for simulating barrier island geomorphologic responses to future storms and sea-level rise." Theoretical and Applied Climatology 136, no. 3-4:1495-1511. PNNL-SA-142865. doi:10.1007/s00704-018-2700-5
• Dai H., X. Chen, M. Ye, X. Song, G. Hammond, B.X. Hu, and J.M. Zachara. 2019. "Using Bayesian Networks for Sensitivity Analysis of Complex Biogeochemical Models." Water Resources Research 55, no. 4:3541-3555. PNNL-SA-141922. doi:10.1029/2018WR023589
• Fang Y., S.B. Yabusaki, A. Ahkami, X. Chen, and T.D. Scheibe. 2019. "An efficient three-dimensional rhizosphere modeling capability to study the effect of root system architecture on soil water and reactive transport." Plant and Soil 441, no. 1-2:33-48. PNNL-SA-138450. doi:10.1007/s11104-019-04068-z
• Gao Z., H. Liu, J.E. Missik, J. Yao, M. Huang, X. Chen, and E.V. Arntzen, et al. 2019. "Mechanistic links between underestimated CO2 fluxes and non-closure of the surface energy balance in a semi-arid sagebrush ecosystem." Environmental Research Letters 14, no. 4:Article Number 044016. PNNL-SA-142139. doi:10.1088/1748-9326/ab082d
• Graham E.B., J.C. Stegen, M. Huang, X. Chen, and T.D. Scheibe. 2019. "Subsurface biogeochemistry is a missing link between ecology and hydrology in dam-impacted river corridors." Science of the Total Environment 657. PNNL-SA-132468. doi:10.1016/j.scitotenv.2018.11.414
• Missik J.E., H. Liu, Z. Gao, M. Huang, X. Chen, E.V. Arntzen, and D.P. McFarland, et al. 2019. "Groundwater-River Water Exchange Enhances Growing Season Evapotranspiration and Carbon Uptake in a Semiarid Riparian Ecosystem." Journal of Geophysical Research: Biogeosciences 124, no. 1:99-114. PNNL-SA-142097. doi:10.1029/2018JG004666
• Rockhold M.L., X. Song, and X. Chen. 2019. "Complex Sources and Impacts on Remediation and Monitoring Approaches." In WM SYMPOSIA (WM 2019), March 3-7, 2019, Phoenix, AZ, Paper No. 19058. Tempe, Arizona:WM Symposia, Inc. PNNL-SA-139412.
• Shuai P., X. Chen, X. Song, G. Hammond, J.M. Zachara, P.D. Royer, and H. Ren, et al. 2019. "Dam Operations and Subsurface Hydrogeology Control Dynamics of Hydrologic Exchange Flows in a Regulated River Reach." Water Resources Research 55, no. 4:2593-2612. PNNL-SA-138598. doi:10.1029/2018WR024193
• Song X., X. Chen, M. Ye, Z. Dai, G.E. Hammond, and J.M. Zachara. 2019. "Delineating Facies Spatial Distribution by Integrating Ensemble Data Assimilation and Indicator Geostatistics with Level-Set Transformation." Water Resources Research 55, no. 4:2652-2671. PNNL-SA-141921. doi:10.1029/2018WR023262
• Yang Q., X. Zhang, J.E. Almendinger, M. Huang, X. Chen, G. Leng, and Y. Zhou, et al. 2019. "Climate change will pose challenges to water quality management in the St. Croix River basin." Environmental Pollution 251. PNNL-SA-143598. doi:10.1016/j.envpol.2019.04.129

2018

• Freedman V.L., P.D. Royer, X. Chen, S.A. Montgomery, and J.J. Garza. 2018. "ATLAS: Story Maps for Communicating Groundwater Cleanup Status - 18510." In Proceedings of the 44th Annual Waste Management Conference (WM2018): Nuclear and Industrial Robotics, Remote Systems and Other Emerging Technology, March 18-22, 2018, Phoenix, AZ, 8, 5530-5538. Tempe, Arizona:Waste Management Symposia, Inc. PNNL-SA-130420.
• Gao M., H. Li, D. Liu, J. Tang, X. Chen, X. Chen, and G. Bloschl, et al. 2018. "Identifying the Dominant Controls on Macropore Flow Velocity in Soils: A Meta-analysis." Journal of Hydrology 567. PNNL-SA-139024. doi:10.1016/j.jhydrol.2018.10.044
• Song X., X. Chen, J.C. Stegen, G. Hammond, H. Song, H. Dai, and E.B. Graham, et al. 2018. "Drought Conditions Maximize the Impact of High-Frequency Flow Variations on Thermal Regimes and Biogeochemical Function in the Hyporheic Zone." Water Resources Research 54, no. 10:7361-7382. PNNL-SA-123922. doi:10.1029/2018WR022586
• Yang Q., J.E. Almendinger, X. Zhang, M. Huang, X. Chen, G. Leng, and Y. Zhou, et al. 2018. "Enhancing SWAT simulation of forest ecosystems for water resource assessment: A case study in the St. Croix River basin." Ecological Engineering 120. PNNL-SA-128496. doi:10.1016/j.ecoleng.2018.06.020
• Zhou T., J. Bao, M. Huang, Z. Hou, E.V. Arntzen, X. Song, and S.F. Harding, et al. 2018. "Riverbed Hydrologic Exchange Dynamics in a Large Regulated River Reach." Water Resources Research 54, no. 4:2715-2730. PNNL-SA-123666. doi:10.1002/2017WR020508

2017

• Bisht G., M. Huang, T. Zhou, X. Chen, H. Dai, G. Hammond, and W. Riley, et al. 2017. "Coupling a Three-Dimensional Subsurface Flow and Transport Model with a Land Surface Model to Simulate Stream-Aquifer-Land Interactions (CP v1.0)." Geoscientific Model Development 10, no. 12:4539-4562. PNNL-SA-123895. doi:10.5194/gmd-10-4539-2017
• Dai H., M. Ye, A.P. Walker, and X. Chen. 2017. "A new process sensitivity index to identify important system processes under process model and parametric uncertainty." Water Resources Research 53, no. 4:3476-3490. PNNL-SA-120642. doi:10.1002/2016WR019715
• Gao Z., E. Russell, J.E. Missik, M. Huang, X. Chen, C.E. Strickland, and R.E. Clayton, et al. 2017. "A novel approach to evaluate soil heat flux calculation: An analytical review of nine methods." Journal of Geophysical Research: Atmospheres 122, no. 13:6934-3649. PNNL-SA-127368. doi:10.1002/2017JD027160
• Johnson T.C., G. Hammond, and X. Chen. 2017. "PFLOTRAN-E4D: A parallel open source PFLOTRAN module for simulating time-lapse electrical resistivity data." Computers & Geosciences 99. PNNL-SA-113670. doi:10.1016/j.cageo.2016.09.006
• Song H., D.G. Thomas, J.C. Stegen, M. Li, C. Liu, X. Song, and X. Chen, et al. 2017. "Regulation-structured dynamic metabolic model provides a potential mechanism for delayed enzyme response in denitrification process." Frontiers in Microbiology 8. PNNL-SA-129317. doi:10.3389/fmicb.2017.01866
• Stegen J.C., C.G. Anderson, B. Bond-Lamberty, A.R. Crump, X. Chen, and N.J. Hess. 2017. "Soil respiration across a permafrost transition zone: spatial structure and environmental correlates." Biogeosciences 14, no. 18:4341-4354. PNNL-SA-122396. doi:10.5194/bg-14-4341-2017
• Wan H., K. Zhang, P.J. Rasch, B. Singh, X. Chen, and J. Edwards. 2017. "A new and inexpensive non-bit-for-bit solution reproducibility test based on time step convergence (TSC1.0)." Geoscientific Model Development 10, no. 2:537-552. PNNL-SA-118076. doi:10.5194/gmd-10-537-2017

2016

• Stegen J.C., A.H. Hurlbert, B. Bond-Lamberty, X. Chen, C.G. Anderson, R.K. Chu, and F. Dini-Andreote, et al. 2016. "Aligning the Measurement of Microbial Diversity with Macroecological Theory." Frontiers in Microbiology 7. PNNL-SA-122085. doi:10.3389/fmicb.2016.01487
• Zachara J.M., X. Chen, C.J. Murray, and G. Hammond. 2016. "River Stage Influences on Uranium Transport in a Hydrologically Dynamic Groundwater-Surface Water Transition Zone." Water Resources Research 52, no. 3:1568-1590. PNNL-SA-112480. doi:10.1002/2015WR018009

2015

• Johnson T.C., R. Versteeg, J.N. Thomle, G.E. Hammond, X. Chen, and J.M. Zachara. 2015. "Four-dimensional electrical conductivity monitoring of stage-driven river water intrusion: Accounting for water table effects using a transient mesh boundary and conditional inversion constraints." Water Resources Research 51, no. 8:6177-6196. PNNL-SA-103949. doi:10.1002/2014WR016129
• Scheibe T.D., E.M. Murphy, X. Chen, A.K. Rice, K.C. Carroll, B.J. Palmer, and A.M. Tartakovsky, et al. 2015. "An Analysis Platform for Multiscale Hydrogeologic Modeling with Emphasis on Hybrid Multiscale Methods." Groundwater 53, no. 1:38-56. PNNL-SA-93006. doi:10.1111/gwat.12179
• Scheibe T.D., X. Yang, X. Chen, and G.E. Hammond. 2015. "A Hybrid Multiscale Framework for Subsurface Flow and Transport Simulations." Procedia Computer Science 51. PNNL-SA-107927. doi:10.1016/j.procs.2015.05.276

2014

• Freedman V.L., X. Chen, S.A. Finsterle, M.D. Freshley, I. Gorton, L.J. Gosink, and E. Keating, et al. 2014. "A high-performance workflow system for subsurface simulation." Environmental Modelling & Software 55. PNNL-SA-92680. doi:10.1016/j.envsoft.2014.01.030

2013

• Chen X., G.E. Hammond, C.J. Murray, M.L. Rockhold, V.R. Vermeul, and J.M. Zachara. 2013. "Applications of Ensemble-based Data Assimilation Techniques for Aquifer Characterization using Tracer Data at Hanford 300 Area." Water Resources Research 49. PNNL-SA-91954. doi:10.1002/2012WR013285
• Over M., Y. Yang, X. Chen, and Y. Rubin. 2013. "A strategy for improved computational efficiency of the method of anchored distributions." Water Resources Research 49, no. 6:3257-3275. PNNL-SA-90988. doi:10.1002/wrcr.20182
• Stegen J.C., X. Lin, J.K. Fredrickson, X. Chen, D.W. Kennedy, C.J. Murray, and M.L. Rockhold, et al. 2013. "Quantifying Community Assembly Processes and Identifying Features that Impose Them." The ISME Journal 7. PNNL-SA-86535. doi:10.1038/ismej.2013.93

2012

• Chen X., G.R. Miller, Y. Rubin, and D. Baldocchi. 2012. "A statistical method for estimating wood thermal diffusivity and probe geometry using in situ heat response curves from sap flow measurements." Tree Physiology 32, no. 12:1458-1470. PNNL-SA-78550. doi:10.1093/treephys/tps100
• Chen X., H. Murakami, H. Murakami, M.S. Hahn, G.E. Hammond, M.L. Rockhold, and J.M. Zachara, et al. 2012. "Three-Dimensional Bayesian Geostatistical Aquifer Characterization at the Hanford 300 Area using Tracer Test Data." Water Resources Research 48. PNNL-SA-78432. doi:10.1029/2011WR010675