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The People behind the UCCE Groundwater Hydrology Program



Thomas Harter, Ph.D.; Nora S. Gustavsson Endowed Professorship in Water Resources, Department of Land, Air, and Water Resources; University of California, Davis. Research Interests: Flow and transport processes in ground water and in the vadose zone; stochastic analysis of such processes in heterogeneous porous systems; numerical modeling; sustainable groundwater management; nonpoint source pollution of groundwater; assessment and remediation of ground water contamination; geostatistics. (see UCCE research). For a list of publications, check out Thomas' resume.

Short Bio

Thomas Harter holds the Nora S. Gustavsson Endowed Professorship in Water Resources at the University of California, Davis after serving as the Robert M. Hagan Endowed Chair for Water Policy and Management from 2007-2020. He has a joint appointment as Professor and as Professor in Cooperative Extension at the Department of Land, Air, and Water Resources, is currently chair of the Hydrologic Sciences Graduate Group, and, as Associate Director of the Center for Watershed Sciences, is a team partner for the World Water Center. Dr. Harter received his BS and MS in Hydrology from the Universities of Freiburg and Stuttgart, Germany; and his PhD in Hydrology from the University of Arizona.  At UC Davis since 1995, he has established a unique research program in agricultural groundwater hydrology developing novel understanding and solutions to address issues at the nexus of groundwater, the unsaturated zone, soils, and agriculture. He is a member of the American Geophysical Union, has been serving on the Board of Directors of the Groundwater Resources Association and of the Water Education Foundation. He is associate editor for the Journal of Environmental Quality. Dr. Harter's research and extension emphasizes the nexus between groundwater and agriculture. His research group focuses on nonpoint-source pollution of groundwater, sustainable groundwater management, groundwater and vadose zone modeling, groundwater resources evaluation under uncertainty, groundwater-surface water interaction, and on contaminant transport. His work uses a range of numerical, statistical, and stochastic modeling approaches, often with field research, to evaluate the impacts of agriculture and human activity on groundwater flow and contaminant transport in complex aquifer and soil systems, and to support development of tools needed in agriculture and by decision- and policy makers to effectively address sustainable groundwater management and water quality issues in agricultural regions. In 2008, Dr. Harter's research and extension program received the Kevin J. Neese Award in recognition of its efforts to engage scientists, regulators, farm advisors, dairy industry representatives, and dairy farmers to better understand the effects of dairy operations on water quality.


  Christopher Conner
  Kavitha Dhanukodi

Efstathios Diamantopoulos; Assistant Project Scientist

Efstathios works on estimating potential risk of nitrate leaching zone. He is originally from Greece and had done 6 years of post doc in Germany before coming to Davis. He considers himself an environmental soil physicist with a strong background on numerical modeling of water flow, solute transport and heat flow in the unsaturated zone. He is interested in the understanding and analysis between the discrepancy of theory predictions and actual observations in the vadose zone. This includes combining theory and observations for different problems, spanning through a variety of spatial scales, i.e. from the pore scale to the regional scale and of different time scales, i.e. days to decades.


Emily Edwards; 3rd year Master in Hydrologic Sciences

Emily's research has been centered on conducting vadose zone contaminant transport analysis for stormwater contaminants entering the subsurface through drywells. The potential for groundwater contamination caused by urban runoff bypassing surface soil and near surface sediment attenuation processes has prevented more widespread use of drywells as a recharge mechnism. She hopes to provide evidence that drywells can be used to recharge groundwater efficiently and safely.

She started as a Lit major but switched to Earth Science in senior year because of one groundwater class she loved so much. 


 Mehdi Ghasemizade; 1st year Post Doc

Mehdi works on the application of numerical and integrated modeling in hydrology with an emphasis on subsurface flow processes. His research mainly deals with reducing complexity in environmental modeling and improving predictive uncertainty of model outputs. He has done his PhD in ETH Zurich aquatic research center (eawag) in Switzerland.

His research at UC Davis is focused on water banking (managed aquifer recharge) where excess water in winter will be diverted from streams to increase the storage in aquifers. He uses integrated models such as IWFM to study how replenishing aquifers may affect stream-flows as well as urban and agricultural demand

Chris Henry

Christopher Henri; 1st year Post Doc

Christopher is interested in the fate and transport of contaminant in heterogeneous aquifers and in improving the risk estimation through stochastic modeling and numerical method development. He is originally from France where he obtained his Master and got his PhD in Civil and Environmental Engineering at UPC in Barcelona.

His research at UCD focuses on providing methods, protocals, criteria and technical tools to enable decision makers to develop policy and guidance for groundwater Anti-Degradation policy.


Jessica Ho; B.S. Environmental Science Management & B.A. Psychology

Jessica is currently responsible for the Groundwater Blog site for Professor Harter. Her research interest includes finding a way to root pro-environmental behaviors in educational settings through social sciences approach. 


Katherine Lockhart; Third Year PhD

Katherine obtained her masters at UC Davis in Civil and Environmental Engineering. She does statistical modeling of nitrate in groundwater in the Central Valley of California. She is interested in the nitrate source tracking and statistical source apportionment. This is her 6th year with Thomas and 3rd year in the hydrology graduate group.


Kimberly Miles; Second year PhD

Kimberly studys water well hydraulics. She participates in the conduction water well annular seal study GROUT. She is funded by California Water Resource Board to explore water/well policy and update well standards. She is originally from Alaska and had worked for BESSTINC. for 2 years before coming to California. 


Pavithra Mishra; Post Doc

Pavithra is a postdoctoral researcher who has been working with Thomas since 2/2016. She is interested in the application of integrated water management models. She is super thankful to find Prof. Harter as a mentor and teacher.


Taryn Parsons; Second year Masters

Taryn is interested in nitrate leaching and world water problems. Her research focuses on the nitrates being leached from dairy in the Central Valley, which is the leading agricultural area in the U.S.. She analyzes annual reports to understand validity and discover trends for the past ten years. A visit to Ghana aspired her to develop technology to take out heavy metals from water.


Ariel Sim; First year Masters

Ariel graduated from UC Davis with a B.S. in Statistics in winter of 2016, but continued pursuing her M.S. in Statistics because of her interest in big data and predictive modeling. Her passion in statistics has led her to become an ambassador for the Math and Physical Sciences Division during her undergrad years, as well as the current VP of the Actuarial Science Association at UC Davis. Ariel's current project involves performing data analysis on groundwater research under Dr. Harter, which focuses on long-term trends of water levels during periods of drought and rain. 


Gus Tolley; Fourth year PhD

Gus is working on numerical modeling (mod flow) of groundwater and surface interactions. As a geology major, he read a lot on catalog desert and is interested in groundwater policy. He then did a lot of mathematical modeling, geochemical samples during his masters in New Mexico. Now he does a lot of numerical modeling which predicts stream flow in Scott River for fish habitat. He plans to go back to consulting after his anticipated graduation by the end of 2017.

  Recent and Past Students, Postdocs, and Visitors
Megan Young; Postdoctoral Scientist, LAWR, UC Davis and USGS, Menlo Park. Megan Young is working jointly with UC Davis and the U.S .Geological Survey Isotope Tracers Project. Megan uses stable isotopes and geochemistry to trace nutrient sources and better understand the impacts of various land uses on surface and groundwater quality. Her current research is focused on using multiple stable isotopes and chemical constituents to examine how different land uses within dairies influence shallow groundwater composition and biogeochemical processes within the groundwater.
 Aaron King's profile photo Aaron King, M.S., EIT.  PhD student in Civil and Environmental Engineering.  Aaron is using census, land-ownership, soils and other data to model septic system densities throughout California.  This product will be used to evaluate the impact of septic systems on ground and surface water quality in the state by comparison with known water quality issues. 
Alex Lam. B.S. student in Civil Engineering at UC Davis (expected graduation: 2014). Born and raised in Paris, France, he moved to San Francisco during his high school years. At UC Davis, he is the Assistant Transportation Director for Picnic Day, a member of Theta Tau, a professional engineering  fraternity, and active in other activities on campus. In our group, he is currently working on a large project collecting and analzying data to better understand nitrogen fluxes in the Central Valley.
  Alison McNally. Ph.D. student in the Geography Graduate Group.  
Antonio Chaj.  B.S. student in Civil Engineering at UC Davis (expected graduation: 2013). Antonio grew up in Guatemala, a country with abundant natural resources. In California, scarcity of water and other natural resources in California piqued his interest. His interest is in creative ways to manage water resources innovatively and sustainably. He is part of our nitrogen flux data and analysis group.
Courtney Hall. Graduate student in Civil and Environmental Engineering at UC Davis. As engineering undergraduate student, Courtney has enjoyed building homes for those in need. Her focus i her graduate studies will be on water quality. She currently works on collecting and analyzing Scott Valley climate and streamflow data.
Emily Chen. B.S. in Environmental Policy Analysis and Planning with an emphasis on City and Regional Planning. She has grown up in an environment where efficient use of resources around the home and in everyday life was an important value. Her interest and focus is on environmental policies and helping communities tweak their daily lifestyle into a more sustainable way of life.
  Giorgos Kourakos, Ph.D., Postdoctoral Researcher. 
Ka Tammy Lau. B.S. in Civil and Environmental Engineering, UC Davis (2012). Her major interests are in hydraulics, soil mechanics, and sustainable design and she is pursuing a career in structural engineering and management.
  Katherine Lockhart. M.S. in Civil and Environmental Engineering, UC Davis (2012), now Ph.D. student in the Hydrologic Sciences Graduate Group.
Kevin Leung. B.S. in Civil and Environmental Engineering, UC Davis (2012). Kevin has a passion for environmental engineering, specifically for learning about and addressing water quality and air pollution issues. He is currently researching nitrogen fluxes in dairy farms in California.
Kristin Dzurella
Kristin Dzurella, Research Analyst.  MSc. Sustainable Resource Management, Technische Universität München (Germany), 2010. BSc. Environmental Horticulture and Restoration Ecology, UC Davis, 2004. Her current work focuses on cropland nitrate fluxes, cropland vulnerability to nitrate leaching, and farm best management practices that increase plant recovery of nitrogen and reduce nitrate loss below the rootzone and to groundwater.
  Laura Foglia, Ph.D., Postdoctoral Researcher.
Olin Applegate 2012
Olin Applegate, B.S. in Environmental Policy Analysis and Planning (UC Davis, 2010).  Currently a graduate student in the Hydrologic Sciences graduate group.  Olin is interested in non-point source contaminant transport of groundwater.  His current project examines the relationship between levels of groundwater nitrate and landuse in California’s San Joaquin Valley.
Stuart Dooley. B.S. student in Civil Engineering at UC Davis (expected graduation: 2013). Stuart enjoys water in many ways: on the UC Davis ICA Water Polo team, river rafting, or in doing research on water quality impacts from dairies.
Triet Nguyen. B.S. student in Exercise Biology at UC Davis (expected graduation: 2013). Growing up in Vietnam, Triet was intimately familiar with an agricultural landscape of field crops and dairy farms. That experience got him interested in working with us on understanding the role of agricultural practices in groundwater quality dynamics and how consumer food choices ultimately effect groundwater quality at the large scale.
William Widger. B.S. student in Civil Engineering at UC Davis (expected graduation: 2013). While on an Education Abroad study year at the university in Freiburg, Germany, Bill - then an economics major - discovered his love for understanding and working with sustainable water systems, energy systems, transportation systems, and waste handling systems. He made the switch to engineering and is engaged in research on understanding groundwater nonpoint source pollution dynamics.


Naoko Watanabe, Ph.D. ; Postdoctoral Research Scientist, LAWR, UC Davis. Naoko received her Ph.D. from the Department of Civil and Environmental Engineering at UC Davis. As an environmental engineer, Naoko is predominantly interested in the fate and transport of emerging contaminants. She is the leading researcher in a several studies on the occurrence and fate of emerging contaminants such as antibiotics and pathogens in confined animal farming (specifically, dairies). Naoko is now a professor at Hokkaido University, Japan.

Yeonjeong Park, Ph.D. ; Postdoctoral Research Scientist, LAWR, UC Davis. Yeonjeong received her Master's degree at Cornell University in 2002 and her Ph.D. at UCLA in 2007. Her research interests include contaminant monitoring and control using sensor networks, contaminant transport modeling in soil and groundwater, risk assessment, and data analysis. She is currently working on Cryptosporidium oocyst transport modeling in porous media. Yeonjeong is now a project scientist with the National Environmental Science Laboratory (Ministry of Environment) in South Korea.
Wei Li, Ph.D.; Postdoctoral Research Scientist, LAWR, UC Davis. Wei is one of our core numerical modelers. His research interests are: numerical simulations of  flow and reactive solute transport in groundwater and the unsaturated zone; geostatistical inference and  uncertainty assessment of parameter distributions from measured data; aquifer tests/field studies to identify hydraulic parameters. He is currently part of the team developing a long-term assessment of groundwater nitrate impacts including those from dairies. Wei is now a researcher at the Universitaet Tuebingen, Germany.
Bill Samuels ; Staff Research Associate, LAWR, UC Davis. Bill ran our dairy field groundwater monitoring program and maintained our database. He is now working the California Department of Water Resources.
Frank Klein ; Postgraduate Researcher, LAWR, UC Davis. Frank's work primarily consists of modeling groundwater systems related to nonpoint sources, especially dairies.  Specifically, he works with nonpoint source nitrate contamination in association with agriculture.  His modeling also involves work with GIS.  Outside of work he does his best to enjoy all that California has to offer, but he usually ends up in the Sierra Nevada on weekends!  He has made his hobby a career, now working for the U.S. Forest Service.


Ryan Hines : Graduate Student Researcher, LAWR, UC Davis. Ryan is developing the Scott Valley Community Groundwater Model. The groundwater model will be used to investigate the effects of various conjunctive use (groundwater and surface water) management approaches in the Scott Valley with respect to preserving and improving the salmon fisheries and beneficial uses of the Scott River while sustaining the nature of a healthy, locally based agricultural economy. Ryan’s research has also focused on groundwater–surface water interactions using temperature as a tracer to determine the variability and localized scale of gains/losses and hyporheic flows. Temperature measurements have been collected using a Distributed Temperature Sensing (DTS) survey technique that provides continuous, high-resolution temperature measurements. These measurements have been combined with fish observation surveys in order to determine if a correlation exists between areas of hyporheic inflow and groundwater accretion, and beneficial salmonid habitats.  Ryan has moved on into the consulting world.
Reid Bryson; Graduate Student Researcher, LAWR, UC Davis. Reid is investigating the fate and transport of steroid hormones originating on beef and dairy cattle facilities. Steroid hormones have been shown to impact water quality by causing sex reversal and endocrine system disruption in aquatic wildlife at very low concentrations. Recent research has detected steroid hormones in surface waters receiving runoff from cattle facilities, particularly those classified as concentrated animal feeding operations. Reid’s research seeks to understand the processes (e.g. microbial degradation and soil adsorption) affecting steroid hormones excreted by cattle under conditions relevant to concentrated cattle production. Plot-scale runoff experiments will generate samples to be analyzed for steroid hormone concentrations and other water quality constituents. Data from these experiments will be used to develop a runoff flow and transport model to evaluate the processes affecting cattle-derived steroid hormones in surface runoff. Additional analysis will attempt to correlate the transport of steroid hormones with more easily quantified water quality constituents. Key project partners included the University of California-Berkeley and the University of Nevada-Reno. Reid is now working as a consultant.

Niall McCarten; Former Graduate Student Researcher, LAWR, UC Davis. Niall McCarten is interested in the hydrology of vernal pool wetlands in the Central Valley of California, working as a consultant.