Spring Semester, 2017 - Jason Gurdak is on sabbatical as a Visiting Scientist at Eawag, Department of Water Resources and Drinking Water, in the Hydrogeology research group. Eawag is the Swiss Federal Institute of Aquatic Science and Technology and is part of the ETH University domain. See more about the projects that he'll be collaborating on here.
February 8, 2017 - Invited seminar by Jason Gurdak titled "A Water-Energy-Food Nexus approach toward sustainable groundwater and agroecosystems", Institute of Environmental Engineering, Hydrology and Water Resources Management, ETH Zurich.
February 2, 2017 - Congrats to MS student Deseret Weeks who was awarded the COAST Graduate Student Research Award. This will help support Deseret's research on the biogeochemical controls of mercury fate and transport and ecological implications in Cache Creek watershed, California. Well done Deseret!
January 23, 2017 - New paper in Nature Geoscience by Jason Gurdak, titled "Groundwater: Climate-induced pumping". See paper here.
October 27-28, 2016 - Jason Gurdak is an invited keynote speaker at the American Geosciences Institute (AGI) Critical Issues Forum on Addressing Changes in Regional Groundwater Resources: Lessons from the High Plains Aquifer. Jason will be speaking about Groundwater Policy in the Face of Climate Change. This Critical Issues Forum is hosted b the Payne Institute for Earth Resources and the Colorado School of Mines.
More information about the Forum here.
October 24, 2016 - News article 'Drought not nixed despite bouts of heavy rainfall' by Katherine Minkiewicz at Golden Gate Xpress; Jason Gurdak discusses aspects of the drought in California.
September 28, 2016 - New EPA report highlights the Hydro Group's recent work (Newcomer et al., 2014) on recharge beneath low impact development. The EPA study shows long-term benefits of green infrastructure and low impact development for groundwater recharge. The new report is titled Estimating monetized benefits of groundwater recharge from stormwater retention practices. Read more here.
June 6, 2016 - Latina SF State graduates honored for academic achievement. Read article in El Tecolote newspaper about Hydro student Claudia Corona's honors at SFSU Commencement. Link to article here.
May 27, 2016 - A big congratulations to Hydro student Claudia Corona for being honored at the 2016 SFSU Commencement at AT&T Park. Claudia is recipient of the Graduate Distinguished Achievement Award and special honors as Hood Recipient for the College of Science and Engineering at SFSU. Claudia has also been invited to offer greetings at Commencement on behalf of her fellow graduate students. Well deserved Claudia!
Read more about Claudia Corona's speech at Commencement here: "My curiosity fuels my adventures and my ambitions to make the world a better place for my family and my friends and for society to grow with nature," said Corona. "So what about you? What are you curious about?"
May 6, 2016 - Congratulations to Hydro student Mehrdad Hejazian for his 3rd Place Award in the Physical Sciences category at the SFSU Student Research Competition.
Februrary 9, 2016 - News article in Circle of Blue "The Most Important Water Stories of 2015", by Brett Walton mentions the GRAPHIC project, which is led by Jason Gurdak.
December 9, 2015 - News article "Why Storing Water for the Future Means Looking Underground" by Laura Bliss at CityLab quotes Jason Gurdak and GRAPHIC's new position paper.
December 2, 2015 - Jason Gurdak gives talk on "Human-environmental security of the water-energy-food nexus in the Asia-Pacific coastal region" at the UCLA-NSF Workshop: Food-Energy-Water Nexus in California, Los Angeles, California. Workshop agenda.
December 1, 2015 - News article in Circle of Blue "Scientists urge greater attention to groundwater in climate adaptation" about Jason Gurdak's research and new (2015) GRAPHIC position paper released at COP21 in Paris, France.
December 1, 2015 - Article in BC Water News "Hydrologist calls for action on groundwater policy".
December 1, 2015 - Jason Gurdak is lead author on GRAPHIC's new (2015) position paper and call to action, which was offically released December 1, 2015 at the COP21 in Paris, France. Additional details about the new publication can be found on GRAPHIC's website here.
November 30, 2015 - News release: "Hydrologist leads global call for action on groundwater management" .
September 13, 2015 - Jason Gurdak organizing a Workshop titled “Groundwater and climate change” at the 42nd International Association of Hydrogeologists (IAH) Congress "Hydrogeology: Back to the Future!", Rome, Italy, September 13-18, 2015. Workshop information here.
September 2, 2015 - Hydro group members attend the Groundwater Resources Association (GRA) of California conference: The New Groundwater Sustainability Plans: Raising the Bar on Groundwater Management. Link to conference agenda here.
August 28, 2015 - Michelle Newcomer's thesis research on low impact development (LID) and managed aquifer recharge is featured in a new article in Environmental Biophysics, titled "Sensors validate California groundwater resource management technique". Link to article
July 7, 2015 - Jason Gurdak will be running a workshop on time series and spectral methods in climate variability analysis related to groundwater research at the G@GPS International Workshop, Tallinn, Estonia, July 5-9, 2015. More info about the workshop here.
May 27, 2015 - Jason Gurdak, Coordinator of UNESCO-GRAPHIC, is giving an invited keynote talk about climate change and groundwater at the World Water Congress XV, International Water Resources Association (IWRA), Edinburgh, Scotland, May 27, 2015. See Congress program here.
May 1, 2015 - Read about G@GPS research and training activities in Zhanjiang, China, here in Quaternary Perspectives (pages 16-17).
April, 2015 - Jason Gurdak is a co-author on the new report titled California's Water: Storing Water, published by the Public Policy Institute of California. This report is part of a briefing kit that highlights California's most pressing water management issues. Link to full report here.
March 4, 2015 - See California WaterBlog: Creating effective groundwater sustainability plans.
September 15, 2014 - Hydro group's new paper published in the Journal of Hydrology: Groundwater level response in U.S. Principal Aquifer to ENSO, NAO, PDO, and AMP, by Amber Kuss and Jason Gurdak. See paper here.
September 15, 2014 - Official launch of the new website for the UNESCO Groundwater Resources Assessment under the Pressures of Humanity and Climate Change (GRAPHIC) program. Visit the new GRAPHIC website here.
September 13, 2014 - Hydro group participates in SFPUC's Westside Watershed Planning workshop. See details here.
August 20, 2014 - Jason Gurdak is U.S. Collaborator on new research project funded by the Partnerships for Enhanced Engagement in Research (PEER) program of the National Science Foundation (NSF) and U.S. Agency for International Development (USAID). Link to Press Release.
Project title: Lebanon - Project 3-26: Assessment of real evapotranspiration and recharge processes on two karst pilot groundwater catchments (Lebanon) using an integrated spatially distributed numerical model: applications for water resources management purposes,
PI: Joanna Doummar, American University of Beirut
U.S. Partner: Jason Gurdak, San Francisco State University,
A complete list of the 39 PEER awards can be found here: PEER Cycle 3 Grant Recipients.
June 10, 2014 - The Hydro group's research on recharge beneath low impact development is highlighted in Eos Research Spotlight, vol. 95, no. 23, page 20. Link to Research Spotlight.
May 29, 2014 - New article in Environmental Monitor features the Hydro group's research on recharge beneath low impact development and the new publication Newcomer et al., 2014. Link to article.
May 20, 2014 - New Hydro student Claudia Corona was awarded the prestigious $10,000 ARCS Scholarship. The ARCS Foundation advances sciences and technology in the United States by providing financial awards to academically outstanding U.S. citizens studying to complete degrees in science, engineering, and medical research. Claudia's research explores the controls of interannual to multidecadal climate variability on groundwater levels and recharge rates to the Principal Aquifers of the United States. Congratulations Claudia!
April 24, 2014 - Article in The Examiner quotes Jason Gurdak: "Blending contaminated SF groundwater with Hetch Hetchy supply makes it safe to drink, experts say".
February 24, 2014 - New publication Newcomer et al. (2014) is selected for Water Resources Research Editor's Highlights: Low impact development boosts groundwater recharge.
March 5, 2014 - Gurdak chairs sessions at the 2014 NEXUS Conference on the "Human-environmental security in Asia-Pacific Ring of Fire: Water-Energy-Food Nexus", University of North Carolina, Chapel Hill, NC. Session details here.
January 29, 2014 - New book chapter publication: Gurdak, J.J., 2014, Chapter 8. Groundwater vulnerability, In Eslamian, S. (Ed.). Handbook of Engineering Hydrology, Volume 3: Environmental Hydrology and Water Management. 33 p., CRC Press.
December 27, 2013 - New publication in Water Resources Research: Newcomer, M.E., Gurdak, J.J., Sklar, L., and Nanus, L., 2013, Urban recharge beneath low impact development and the effects of climate variability and change, Water Resources Research, doi:10.1002/2013WR014282.
November 25, 2013 - New publication in EOS: Taniguchi, M., Allen, D., and Gurdak, J.J., 2013, Optimizing the Water-Energy-Food nexus in the Asia-Pacific Ring of Fire, EOS, vol. 94(47), p. 435, doi:10.1002/2013EO470005.
October 3, 2013 - Jason Gurdak has been a contributing member of the California Department of Food & Agriculture (CDFA) Climate Change Consortium for Specialty Crops. Today, the CDFA Climate Change Consortium for Specialty Crops has produced the report titled: Climate Change Consortium for Specilty Crops - Impacts and Strategies for Resilience, which identifies recommondations to address the challenges posed by climate change to producers of specialty crops in California.
The Consortium is a diverse group of individuals involved in California specialty crop agriculture that has addressed climate change impacts in the areas of temperature, water resources, pests, and pollination, with the understanding that growers will face changes in environmental averages, trends, variability, and extremes. Impacts to agriculture from changes in weather will be felt differently in different parts of California.
There was a general consensus within the Consortium that growers are already managing their lands in consideration of dynamic environmental variables. However, for specialty crop agriculture in California to adapt and be prepared for the effects of climate change, growers will require technological innovation, scientific answers to fundamental climate change impact questions, investment in planning and preparedness, and agricultural support services.
This report and the efforts of the Climate Change Consortium are an extension of Ag Vision, a blueprint for sustainability developed by the California State Board of Food and Agriculture in 2010. One of Ag Vision’s key strategies is to assure agricultural adaptation to climate change. The Climate Change Consortium report is also part of a broader body of research about the impacts of climate change in California and how the state can prepare for them.
Link here to the new report: Climate Change Consortium for Specialty Crops - Impacts and Strategies for Resilience.
August 7, 2013 - New NSF Hydrologic Sciences funded project (2013-2016): RUI: Groundwater teleconnections with interannual to multidecadal climate variability
June 19, 2013 - New publication in Journal of Hydrology: Klove, Ala-Aho, Bertrand, Gurdak, Kupfersberger, Kvaener, Muotka, Mykra, Preda, Rossi, Uvo, Velasco, and Pulido-Velazquez, 2013, Climate change impacts on groundwater and dependent ecosystems. Journal of Hydrology.
May 24, 2013 - Congratulations to hydro student Ryan Corbett (MS, Geosciences) as recipient of the 2013 Pestrong Graduate Teaching Assistant Award.
May 22, 2013 - Hydro student Elzie Velasco was awarded the prestigious $10,000 ARCS Scholarship. The ARCS Foundation advances sciences and technology in the United States by providing financial awards to academically outstanding U.S. citizens studying to complete degrees in science, engineering, and medical research. Elzie's research explores the controls of interannual to multidecadal climate variability on groundwater levels and recharge rates to the Principal Aquifers of the United States. Results of her research are important because time-varying recharge rates can be used to greatly improve local to national-scale groundwater sustainability studies. Congratulations Elzie!
May 17, 2013 - Congratulations to hydro student Ryan Corbett (MS, Geosciences) as a winner of the SFSU COSE Student Project Showcase.
May 15, 2013 - Congratulations to hydro students Mays Danfoura, Elzie Velasco, and Mike Wrigley (MS, Geosciences) as recipients of the 2013 Dawdy Hydrology Research Grant.
November 26, 2012 - New publication in Nature Climate Change:
Taylor et al., Groundwater and climate change, doi:10.10.1038/nclimate1744.
July 5, 2012 - New publication in Climate Science and Policy:
Gurdak, J.J., 2012, Climate change goes underground: Implications for groundwater. Climate Science and Policy, July 5, 2012, (Invited contribution).
June, 2012 - New publication in Environmental Pollution:
Nanus, L., Clow, D.W., Saros, J.E., Stephens, V.C., Campbell, D.H., 2012, Mapping critical loads of nitrogen deposition for aquatic ecosystems in the Rocky Mountains, USA, Environmental Pollution
May, 2012 - New publication in Environmental Science & Technology:
Gurdak, J.J., and Qi, S.L., 2012, Vulnerability of recently recharged groundwater in principal aquifers of the United States to nitrate contamination, Environmental Science and Technology, doi:10.1021/es300688b.
April 2, 2012 - Congratulations to Hydro student Michelle Newcomer (MS, 2012 anticipated) for her acceptance into the PhD program at UC Berkeley, Department of Civil and Environmental Engineering!
March 14, 2012 - BBC article about Jason Gurdak's research on climate change and groundwater. Read here: Cambio climatico: el agua subterranea sera cada vez mas vital
March 13, 2012 - Professor's groundwater research gains international attention. Read more here.
March 13, 2012, 11:00 to 13:00 - Jason Gurdak invited panelist at the 6th World Water Forum session TSG 3.3.2 "Coping with uncertainties related to climate and global change in water planning and management", Marseille, France. Links to Session Program here. Session Flyer here.
March 12, 2012 - Climate change may reduce future use of groundwater. Read more here.
March 5, 2012 - UN scientists warn of increased groundwater demands due to climate change. Read more here.
February, 2012 - Congratulations to former Hydro student Amber Kuss (MS, 2011) for her acceptance into the PhD program in the Environmental Studies Department at U.C. Santa Cruz!
January, 2012 - Background arsenic soil concentration quantified:
Findings from Dylan Duverge's recent (2011) MS thesis is featured in the San Francisco Bay Regional Water Quality Control Board, Executive Officer's Report, January 2012. Dylan's thesis provides the first regional estimate of background arsenic concentrations (11 mg/kg) in the San Francisco Bay Region.
January, 2012 - Most downloaded Journal of Hydrology article in last 90 days:
Green, T.R., Taniguchi, M., Kooi, H., Gurdak, J.J., Allen, D.M., Hiscock, K.M., Treidel, H., and Aureli, A., 2011, Beneath the surface of global change: Impacts of climate change on groundwater, Journal of Hydrology, doi:10.1016/j.jhydrol.2011.05.002.
January, 2012 - Remote Sensing Technologies & Applications (HydroVisions page 11):
Hydro MS student Michelle Newcomer mentioned in HydroVision (California Groundwater Resource Association) for her presentation on estimating groundwater storage change in the Central Valley using GRACE (Gravity Recovery and Climate Experiment) satellite data.
January, 2012 - Climate Change/Enhancing Groundwater Reserves (HydroVisions pg 12):
Jason Gurdak mentioned in HydroVision (California Groundwater Resource Association) for his presentation on climate variability effects on groundwater in the Central Valley and Basin and Range aquifes and the importance toward better management and planning.
December, 2011 - New book and book chapter in print:
Treidel, H., Martin-Bordes, J.J., and Gurdak, J.J.,2011. Climate change effects on groundwater resources: A global synthesis of findings and recommendations, IAH - International Contributions to Hydrogeology, Taylor and Francis publishing.
Gurdak, J.J., McMahon, P.B., and Bruce, B.W., 2011, Vulnerability of groundwater quality to human activity and climate change and variability, High Plains aquifer, USA, In Treidel, H., Martin-Bordes, J.J., and Gurdak, J.J., (Eds.). Climate change effects on groundwater resources: A global synthesis of findings and recommendations, IAH - International Contributions to Hydrogeology, Taylor and Francis publishing.
September 12, 2011 - New article by Amber Kuss, a recent MS graduate (2011) of our Hydrogeology group, in HydroVisions, a publication of the Groundwater Resources Association of California:
July, 2011 - New paper about climate variability and groundwater in England:
Holman, I., Rivas-Casado, M., Bloomfield, J., and Gurdak, J.J., 2011, Identifyin non-stationary groundwater level response to North Atlantic ocean-atmosphere teleconnection patterns using wavelet coherence, Hydrogeology Journal, doi:10.1077/s10040-011-075509.
July, 2011 - New review paper about climate climate and groundwater:
Green, T.R., Taniguchi, M., Kooi, H., Gurdak, J.J., Allen, D.M., Hiscock, K.M., Treidel, H., and Aureli, A., 2011, Beneath the surface of global change: Impacts of climate change on groundwater, Journal of Hydrology, doi:10.1016/j.jhydrol.2011.05.002
May 19, 2011 – Congratulations to hydrogeology student Ryan Corbett (MS, Geosciences) as recipient of the 2011 Dawdy Hydrology Research Grant.
April 14, 2011 – Congratulations to hydrogeology student Michelle Newcomer (MS, Geosciences) as recipient of a 2011 Geological Society of America (GSA) Graduate Student Research Grant.
March 9, 2011 – Congratulations to hydrogeology student Amber Kuss (MS, Geosciences) for winning the Physical and Mathematical Sciences category of the 2011 SFSU Student Research Competition. Amber will represent SFSU later this year in Fresno at the CSU-wide competition. The title of her talk was "Effects of climate variability on recharge in regional aquifers of the United States".
March 4, 2011 – Congratulations to hydrogeology student Michelle Newcomer (MS, Geosciences) as recipient of the 2011 G.A. Harris Research Instrumentation Fellowship. Michelle will use Decagon Devices field instruments to quantify the quantity and quality of infiltration beneath rain gardens and subsequent recharge to the Westside Basin aquifer in San Francisco.
December 13-17, 2010 – Jason Gurdak is co-chair of the session H08: Water-resource science and strategies for adaptaion to climate variability and change, American Geophysical Union (AGU) Fall Meeting 2010, San Francisco, California.
September 29, 2010 – Hydrogeology student and NASA Ames DEVELOP team member Michelle Newcomer (MS Geosciences) is quoted in NASA Ames news article: NASA Ames Scientists Train the Next Generation of Earth Explorers. "I heard about the internship program while attending San Francisco State University, said Michelle Newcomer. "I applied because it sounded really exciting. I wanted to apply my geographic information system (GIS) and remote sensing skills to real-world projects."
June 18, 2010 – Gurdak and hydrogeology group awarded $11k from SFSU Office of Research and Sponsored Projects (ORSP) Funding Opportunities Announcement: Facilitating Research at San Francisco University (ORSP FOA 2010-11). The project titled "Preparing the SF State Community to Understand Climate Change Effects on Groundwater Resources in San Francisco" and will support the installation of a long-term research and teaching "Hydroclimatology Field Lab" site on campus to study the effects of climate change and variability on recharge and contamination transport to the Westside Basin Aquifer located beneath SF State. Michelle Newcomer will use data from the Hydroclimatology Field Lab for her MS thesis research.
June 13-15, 2010 – National Center for Atmospheric Research (NCAR), Advanced Study Program, Junior Faculty Forum on Future Scientific Directions (2010). Gurdak co-chair for session #1: Climate and Water: Advancing adaptation science and strategies for water-resource vulnerability from climate variability and change. Additional info posted on Climate and Water Wiki page.
June, 2010 – New (invited) article by Gurdak in Prairie Fire (a Great Plains regional journal of public policy and the arts): "The High Plains aquifer, part two"
May, 2010 – New (invited) article by Gurdak in Prairie Fire (a Great Plains regional journal of public policy and the arts): "The High Plains aquifer, part one"
April, 2010 – Congratulations to hydrogeology student Michelle Haskins (BS, Geology) for selection to the 2010 National Science Foundation (NSF) Research Experience for Undergraduates (REU) at SUNY New Paltz, New York. This summer Michelle will work with other undergraduate researchers on a comprehensive approach to watershed characterization of the source water for New York City. Details about NSF REU SUNY New Paltzt: http://www.newpaltz.edu/geology/nsf-reu/
April, 2010 – Congratulations to hydrogeology student Amber Kuss (MS, Geosciences) for selection to the 2010 NASA DEVELOP National summer internship program, NASA Ames Research Center, Moffett Field, CA. Amber will work on an earth science research project, mentored by science advisors from NASA and partner agencies, and extend research results to local communities. Details about NASA DEVELOP internship program: http://develop.larc.nasa.gov/index.html
November 6, 2009 – Obi Nzewi (Groundwater Specialist with the San Francisco Public Utility Commission) leads groundwater-quality sampling demonstration for the GEOL 475&775 Hydrogeology class. Photos: pic 1, pic 2, pic 3, pic 4, pic 5, and pic 6.
October 28, 2009 – Gurdak invited talk titled "Recharge and chemical transport and storage in the vadose zone, High Plains aquifer" at the Nebraska Grout Study report release and conference, sponsored by the University of Nebraska - Lincoln.
October 22, 2009 – Gurdak co-chair with Shannon McNeeley (NCAR) of selected forum topic titled "Climate and Water: Advancing adaptation science and strategies for water-resource vulnerability from climate variability and change" for the National Center for Atmospheric Research (NCAR) 2010 Junior Faculty Forum on Future Scientific Directions, to be held in Summer 2010, Boulder, CO.
October 14, 2009 – Dr. Yossi Yechieli (Geological Survey of Israel), international expert on saltwater intrusion in coastal aquifers, guest lectures to GEOL 475&775 Hydrogeology class about saltwater intrusion of coastal groundwater resources in the Middle East.
Newspaper, Book, and Radio Interviews
2009 – “High Plains Water Currently "Acceptable"", The Aquifer: A publication fo the Groundwater Foundatio (http://www.groundwater.org/au/archives/AQ_2402.pdf), vol. 24, no. 2, Fall 2009
2009 – “USGS: Ogallala aquifer water quality currently acceptable": JournalStar.com, July 19, 2009
2009 – “High Plains aquifer water ok for now”, Associated Press.
2009 – "Future aquifer water supplies could be in jeopardy", Denver Post.
2009 – “High Plains aquifer water quality currently acceptable but human activities could limit future use”, USGS News Release.
2008 – “Recharge to the Ogallala aquifer beneath Playas”, Playa Lake Joint Venture Radio program aired on National Public Radio (NPR) affiliates across the Great Plains region, aired August 2008.
2008 – “Japan’s Food Security” by Tokuji Hisada, The Hokkaido Shimbun Press (1.8 million readers and 7th largest newspaper in Japan).
Recent Scientific Manuscripts
Nitrate Contamination of Groundwater:
Gurdak, J.J., and Qi, S.L., 2006. Vulnerability of recently recharged ground water in the High Plains regional aquifer to nitrate contamination. USGS Scientific Investigations Report 2006-5050.
Global Change and Groundwater:
United Nations Educational, Scientific and Cultural Organization (UNESCO) (Gurdak, J.J. is one of 19 contributing authors), 2008. Groundwater resources assessment under the pressures of humanity and climate change (GRAPHIC) – A framework document, GRAPHIC Series N°2, UNESCO Pub., Paris, France, 31 p.
Interannual to Multidecadal Climate Variability and Water Resources:
Gurdak, J.J., Hanson, R.T., McMahon, P.B., Bruce, B.W., McCray, J.E., Thyne, G.D., and R.C. Reedy, 2007. Climate variability controls on unsaturated water and chemical movement, High Plains aquifer, USA. Vadose Zone Journal 6(3), 533-547, doi: 10.2136/vzj/2006.0087.
Groundwater and Climate Change:
Gurdak, J.J., Hanson, R.T., and Green, T.R., 2009. Effects of climate variability and change on groundwater resources of the United States, U.S. Geological Survey Fact Sheet 2009–3074, 4 p.
Vulnerability Assessment of Water Resources:
Gurdak, J.J., 2008. Ground-water vulnerability: Nonpoint-source contamination, climate variability, and the High Plains aquifer, VDM Verlag Publishing, Saarbrucken, Germany, ISBN: 978-3-639-09427-5, 223 p.
Vulnerability of Public-Supply Wells to Land-Use Change (Central Valley):
McMahon, P. B., K. R. Burow, L. J. Kauffman, S. M. Eberts, J. K. Böhlke, and Gurdak, J.J., 2008. Simulated response of water quality in public supply wells to land use change, Water Resources Research, 44, W00A06, doi:10.1029/2007WR006731,
Nonpoint-Source Groundwater Contamination:
Gurdak, J.J., McMahon, P.B., Dennehy, K.F., and Qi, S.L., 2009. Water quality in the High Plains Aquifer, Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming, 1999–2004: U.S. Geological Survey Circular 1337, 63 p.
Gurdak. J.J., and Roe, C.D, Gurdak. J.J., and Roe, C.D, 2009. Recharge rates and chemistry beneath playas of the High Plains aquifer – A literature review and synthesis, U.S. Geological Survey Circular 1333, 39 p.
Gurdak, J.J., Walvoord, M.A., and McMahon, P.B., 2009. Susceptibility to enhanced chemical migration from depression-focused preferential flow, High Plains aquifer, Vadose Zone Journal, v. 7, no. 4, 1172–1184, doi: 10.2136/vzj2007.0145.
Gurdak, J. J., Greve, A. I., and Spahr, N. E., 2002. Water-quality data analysis of the Upper Gunnison River Watershed, Colorado, 1989-99. USGS Water-Resources Investigations Report 02-4001, 61 p.
Agricultural Effects on Groundwater:
Bruce, B.W., Becker, M.F. Pope, L.M., and Gurdak, J.J., 2003. Ground-water quality beneath irrigated agriculture in the Central High Plains aquifer, 1999-2000. USGS Water-Resources Invest. Report 03-4219, 39 p.
High Plains (Ogallala) Aquifer:
McMahon, P.B., Dennehy, K.F., Bruce, B.W., Gurdak, J.J., and Qi, S.L., 2007. Water-quality assessment of the High Plains aquifer, 1999-2004, USGS Professional Paper 1749, 212 pp.
Gurdak, J.J., and McCray, J.E., 2005. Groundwater vulnerability to pesticides: statistical approaches, in Lehr, J.H. and Keeley, J., Water Encyclopedia: Ground Water, John Wiley & Sons, ISBN: 0-471-44164-3, 594–599
Gurdak, J.J., McCray, J.E., Thyne, G.D., and Qi, S.L., 2007. Latin hypercube approach to estimate uncertainty in ground water vulnerability. Ground Water, 45, 3, 348-361, doi: 10.1111/j.1745-6584.2006.00298.x.
Geographic Information System (GIS) Model Development:
Gurdak, J.J. Qi, S.L., and Geisler, M.L., 2009. Estimating prediction uncertainty from geographical information system raster processing: A user’s manual for the Raster Error Propagation Tool (REPTool), U.S. Geological Survey Techniques and Methods 11–C3, 71p.
Gurdak, J. J., Spahr, N., E., and Smijtzer, R., 2002. Traveltime characteristics of Gore Creek and Black Gore Creek, Upper Colorado River Basin, Colorado, USGS Water-Resources Invest. Report 02-4037, 14 p.
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