Water Across Interfaces

CUAHSI's Second Biennial Science Meeting

Boulder, CO 19-21 July 2010 Acknowledgements

CUAHSI would like to acknowledge the contributions, support and assistance from the following organizations and individuals:

The National Science Foundation. This meeting is being supported, as part of a cooperative agreement with CUAHSI – NSF/EAR-07-53521.

University Consortium for Atmospheric Research (UCAR) for providing facilities and logistical support. In particular Larry Winter, NCAR Deputy Director, for authorizing sponsorship of the meeting and David Gochis NCAR Research Application Laboratory and The Institute for Integrative and Multidisciplinary Earth Studies, for serving as the official meeting host. Additionally, Debbie Griffin, Michelle Rangel and Paula Robinson, for meeting planning and facilities support.

The CUAHSI Biennial Program Planning Committee, chaired by Claire Welty, for organizing the meeting technical content. Program committee members included Adam Ward, David Chandler, Jim McNamara, Brian Waldron, Tissa Illangasekare, Juan Valdes, and Mark Hamilton.

CUAHSI member institutions for their continuing support.

And, the CUAHSI staff, Jessica Annadale, Yoori Choi, Lisa Gray, David Kirschtel, and Conrad Matiuk for their efforts in organizing and managing this meeting.

Image credit: background image for program cover and badges - “The Big Splash” by annua22a, flickr.com under creative commons type 3 license BY-NC-SA.

CUAHSI Corporate Officers

President and Executive Director - Richard Hooper Secretary - Kevin Dressler Treasurer - Brian Waldron

CUAHSI Board of Directors

Lawrence Band *, Chair

Jay Famiglietti • * Carol A. Johnston Lawrence Murdoch º * David L. Freyberg Witold Krajewski Aaron Packman Robyn Hannigan Patricia Maurice Kenneth Potter Tissa Illangasekare Jim McNamara * Scott Tyler Jennifer Jacobs * Claire Welty

* members of the executive committee • Past Chair º Chair-elect

CUAHSI Members

Institutional Members

AK University of Alaska - Fairbanks IN Purdue University NY State University of New York - AL University of Alabama University of Notre Dame Buffalo Auburn University KS University of Kansas Cornell University AR Arkansas State University Kansas State University State University of New York - ESF University of Arkansas KY Murray State University Clarkson University AZ Northern Arizona University University of Kentucky Columbia University University of Arizona LA Louisiana State University OH Ohio State University Arizona State University MA Tufts University OK Oklahoma State University CA University of California - Irvine Woods Hole Oceanographic Inst. University of Oklahoma Stanford University Massachusetts Institute of OR Oregon State University University of California - Davis Technology Portland State University University of California - Merced Northeastern University PA Carnegie Mellon University University of California - Riverside University of Massachusetts University of Pennsylvania University of California - Los Angeles Harvard University Drexel University University of California - Santa University of Massachusetts - Temple University Barbara Boston Pennsylvania State University University of California - Berkeley MD Johns Hopkins University University of Pittsburgh CO Colorado School of Mines University of Maryland - College RI University of Rhode Island University of Colorado Park SC Clemson University University of Colorado - Colorado University of Maryland - Baltimore University of South Carolina Springs County SD South Dakota State University Colorado State University MI Michigan State University TN University of Tennessee CT University of Connecticut MN University of Minnesota University of Memphis DE University of Delaware MS University of Mississippi TX Texas State University - San Marcos FL Florida State University MT Montana State University University of Texas - El Paso University of Miami University of Montana University of Texas - Arlington University of Florida NC Duke University University of Texas - San Antonio Florida International University University of North Carolina - University of Texas - Austin University of South Florida Chapel Hill Texas A&M University University of Central Florida ND University of North Dakota UT Utah State University GA Georgia Institute of Technology NE University of Nebraska University of Utah University of Georgia NH University of New Hampshire Brigham Young University IA Iowa State University Dartmouth College VA George Mason University University of Iowa NJ Princeton University Virginia Tech University ID University of Idaho Rutgers University (SUNJ) VT University of Vermont Idaho State University NM New Mexico State University WA University of Washington Boise State University University of New Mexico Washington State University IL University of Illinois New Mexico Tech WI University of Wisconsin Northwestern University NV University of Nevada - Reno WV West Virginia University Southern Illinois University University of Nevada - Las Vegas WY University of Wyoming

Affiliate Members International Affiliate Members

IL Eastern Illinois University AUS Commonwealth Scientific and DNK University of Copenhagen MA Smith College Industrial Research Org. GBR Centre for Ecology and MD Smithsonian Environmental Queensland University of Hydrology Research Center Technology ITA University of Padova NC RTI International University of Queensland University of Trento NH Plymouth State University CAN University of British Columbia JPN Yonsei University NV Desert Research Institute University of Calgary SVN University of Ljubljana OH Cleveland State University University of New Brunswick SWE Swedish Hydrological Council University of Quebec - Institute National de la Recherche Scientifique University of Waterloo

Detailed Schedule

CUAHSI 2010 Biennial Detailed Session Schedule Monday, July 19 Time Session Room

7:30 – 8:30am Registration & Breakfast Lobby

8:30 – 8:45am Rep. Grace Napolitano (CA-38), Chair, Water & Power Subcommittee of the House Natural Resources Committee Introduction by Jay Famiglietti

General Welcome 8:45 – 9:00am Richard Hooper, Executive Director, CUAHSI Auditorium Lawrence W. Band, Board Chair, CUAHSI Claire Welty, Conference Chair, CUAHSI

Welcoming Remarks: Roger Wakimoto, Director – NCAR

9:00 – 9:45am Keynote: P.C.D. (Chris) Milly, Geophysical Fluid Dynamics Laboratory - Global hydrology: riding the interface between yesterday and tomorrow

8:30am – 6:00pm Posters available for viewing 1210

9:45 – 10:15am Break

10:15am – Session 1A – The Atmosphere - Land Surface Interface 12:15pm Moderator: Jennifer Jacobs 1214

10:15 – 10:45 Jay Famiglietti – The human fingerprint on land-atmosphere interactions 10:45 – 11:15 Reed Maxwell – Development of a groundwater-atmospheric model and its use in diagnosing land-atmosphere interactions 11:15 – 11:45 Marc Parlange - Land - atmosphere interactions: field studies and simulations 11:45 – 12:15 Discussion

10:15am – Session 2A – The Groundwater - Surface Water Interface 12:15pm Moderator: Larry Murdoch 1212

10:15 – 10:45 James Kirchner – Hydrological processes revealed by high- frequency chemical dynamics spanning the periodic table 10:45 – 11:15 Judson Harvey – Ecologically relevant measures of groundwater- surface water interactions in flowing aquatic ecosystems 11:15 – 11:45 Aaron Packman – Multi-scale solute and particle transport in rivers

11:45 – 12:15 Discussion

12:15 – 2:00pm Lunch Lobby

2:00 – 4:00pm Session 1B – The Atmosphere - Land Surface Interface Moderator: David Chandler 1214

2:00 – 2:30 William Kustas – Application of thermal temote sensing for multi- scale estimation of evapotranspiration and drought 2:30 – 3:00 Guido Salvucci – The Bouchet-Morton Complementarity Hypothesis: An example of land-atmosphere coupling and an

explanation of pan evaporation 3:00 – 3:30 Peter Troch – Hydrological partitioning, vegetation water use and climate sensitivity at catchment scales 3:30 – 4:00 Discussion

Schedule - 1 Time Session Room

2:00 – 4:00pm Session 2B – The Groundwater - Surface Water Interface Moderator: David Freyberg 1212

2:00 – 2:30 Roy Haggerty – Surface water or hyporheic transient storage in streams - a false dichotomy? 2:30 – 3:00 Stefan Krause – Hot moments in cold spots - Distributed sensor networks for investigating multi-component reactive transport processes at aquifer-river interfaces 3:00 – 3:30 David Genereux – Coupled water and nitrogen fluxes through a streambed in an agricultural watershed: measurements, patterns, controls 3:30 – 4:00 Discussion

4:00 – 6:00pm Mixer Lobby

Poster presentations with author(s) present 1210

Schedule - 2 Tuesday, July 20 Time Session Room

7:30 – 8:30am Registration & Breakfast Lobby

8:30 – 9:30am Plenary – “Reds” Wolman Lecture

Auditorium Gordon Grant, Research Hydrologist, USDA Forest Service "Is it a big number or a little number?": Building a societally relevant hydrologic science for the 21st century

8:30am – 6:00pm Posters available for viewing 1210

9:30 – 10:00am Break

10:00 – noon Session 3 – The Land Surface - Groundwater Interface Moderator: Adam Ward 1214

10:00 – 10:30 Brian Smerdon – Attempting to quantify fluxes across the water table: Gleaning some insight from modeling unsaturated flow in semi-arid and sub-humid regions 10:30 – 11:00 Gene-Hua Crystal Ng – Identifying land-surface controls on diffuse recharge: What we can learn by integrating model simulations and unsaturated zone data 11:00 – 11:30 Steven Loheide – The groundwater component of ET and the groundwater subsidy provided to vegetation: Equivalent 11:30 – noon quantities? Discussion

10:00 – noon Session 4 – The Natural System - Human System Interface 1212 Moderator: Claire Welty

10:00 – 10:30 Peter Weiskel – Water-use regimes: Characterizing direct human interactions with the hydrosphere 10:30 – 11:00 Jeanne VanBriesen – Engineered and natural water systems: Sensing and modeling at the interfaces 11:00 – 11:30 Barbara Minsker – Improving management of fluxes across the human-natural interface: A real-time control system for combined sewer overflows 11:30 – noon Discussion

Noon – 2:00pm Lunch Lobby

2:00 – 4:00pm Session 5 – The Transition Zone Between Hillslope and Channel 1214 Moderator: Tissa Illangasekare

2:00 – 2:30 Kevin McGuire – The concept of hydrological connectivity of hillslopes and streams: Open questions and ways forward 2:30 – 3:00 Kelsey Jencso – Controls on landscape hydrologic connectivity and riparian buffering: Implications of catchment structure for streamflow generation and source water dynamics 3:00 – 3:30 Ciaran Harman – Scaling up hydrologic predictions from hetero- geneous soils to heterogeneous catchments - challenges and new approaches 3:30 – 4:00 Discussion

Schedule - 3 Time Session Room

2:00 – 4:00pm Session 6 – Advances in the Understanding of Floods Moderator: Brian Waldron 1212

2:00 – 2:30 Katherine Hirschboeck – Connecting flooding and climatic variability: What are the missing links? 2:30 – 3:00 Witold Krajewski – A diagnostic framework for the prediction of floods: the Iowa flood of June, 2008 3:00 – 3:30 James A. Smith – The Climatology of flooding for the United States east of the Rocky Mountains 3:30 – 4:00 Discussion

4:00 – 6:00pm Free Time

6:00 – 9:00pm Reception & Banquet (transportation will be provided to Mesa Lab leaving Center Mesa Lab Green Campus at 5:30pm with return trips to conference hotels)

Schedule - 4 Wednesday, July 21 Time Session Room

7:30 – 8:30am Registration & Breakfast Lobby

8:30 – 9:30am Plenary – Peter Eagleson Lecture

Ignacio Rodriguez-Iturbe, James S. McDonnell Auditorium Distinguished University Professor of Civil and Environmental Engineering, Princeton University

8:30am – noon Posters available for viewing 1210

9:30 – 10:00am Break

10:00 – noon Session 7 – Catchment Comparison Exercise 2010 Moderator: Jim McNamara 1214

10:00 – 10:30 Jim McNamara – Storage dynamics as a metric of catchment intercomparison 10:30 – 11:00 Chris Soulsby – Reconciling storage estimates in montane catchments: hydrometric and tracer-based approaches in inter- catchment comparisons 11:00 – 11:30 Kevin Bishop – Riparian zone control on stream dissolved organic carbon dynamics: Using storage to define the limits of DOC flushing during spring flood 11:30 – noon Discussion

10:00 – noon Session 8 – Fiber optic lessons learned Moderators: Scott Tyler & John Selker 1212

10:00 – 10:30 Barry Freifeld – Distributed thermal perturbation sensing for monitoring subsurface processes 10:30 – 11:00 John Lane – Use of distributed-temperature sensing systems by the U.S. Geological Survey 11:00 – 11:30 Michael Mondanos – Distributed thermal perturbation sensing for monitoring subsurface processes 11:30 – noon Discussion

Noon – 2:00pm Lunch Lobby

Schedule - 5 CUAHSI 2010 Biennial Workshop Schedule

Wednesday, July 21 Time Workshop Room

1:00 – 6:00pm HIS Workshop Convenors: Jon Goodall, Dan Ames & Jeff Horsburgh 1212

2:00 – 4:00pm Professional Development for Students Moderator: Adam Ward 2126 Jeff McDonnell – How to write a scientific paper

2:00 – 4:00pm Catchment Comparison Workshop Convenor: Jim McNamara 1214

2:00 – 4:00pm Synthesis Town Hall 1210

Thursday, July 22 Time Workshop Room

7:30am – 7:00pm Distributed Optical Fiber Temperature Sensing Convenors: John Selker & Scott Tyler 1212

8:30 – noon NCAR Tour for Graduate students  Tour limited to 30; sign up at registration desk  Transportation to and from Mesa Lab will be provided Mesa Lab  Lunch provided back at the Center Green

8:30am – 5:00pm HIS Workshop Convenor: Yoori Choi 1214

8:30am – 4:00pm Data- and Modeling-Driven Geoinformatics Modules for Hydrology Education 1210 Convenors: Venkatesh Merwade & Ben Ruddell

10:00 – 10:15am Break

2:45 – 3:00pm Break

Noon – 1:30pm Lunch through café line Café

Schedule - 6 Schedule - 7 Schedule - 8

Plenary Speaker Biographies

P.C.D. ("Chris") Milly, U.S. Geological Survey P.C.D. ("Chris") Milly is a research hydrologist with the U.S. Geological Survey (USGS). Stationed at the National Oceanic and Atmospheric Administration's Geophysical Fluid Dynamics Laboratory (GFDL) in Princeton, NJ, since 1988, he is responsible for representation of land physics in GFDL's evolving suite of climate and earth-system models, and he uses those models in research on global hydrology. Chris's research over the last decade has addressed the issue of detection and attribution of global hydroclimatic change. His findings support the hypothesis that the global pattern of hydroclimatic change observed during the 20th century bears the signature of forced global climate change, largely anthropogenic. Recently, he forged a widely cited statement by prominent scientists, calling attention to the practical challenge of hydroclimatic non-stationarity. He has spoken for the USGS on hydrologic aspects of climate change in a U.S. Congressional briefing and in testimony before the U.S. Senate Subcommittee on Water and Power. Findings from his research project generated statements about future water availability that became highlighted conclusions of the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. He has given interviews for dozens of news media outlets, including the BBC World Service, Los Angeles Times, Le Monde, National Public Radio, Nature, New York Times, San Francisco Chronicle, TV Asahi (Japan), TV Globo (Brazil), United Press International, and Washington Post. Chris lives in the headwater area of the Raritan River, but goes for frequent runs in the adjacent Delaware River basin. He is a Fellow of the American Geophysical Union.

Gordon Grant, USDA Forest Service Gordon Grant is a Research Hydrologist with the USDA Forest Service at the Pacific Northwest Research Station in Corvallis, Oregon, and also Courtesy Professor of Geosciences at Oregon State University. Following a decade-long career as a whitewater river guide, he received his Ph.D. from Johns Hopkins University in 1986 under the tutelage of Professor M. Gordon (Reds) Wolman.

He began his career with the research branch of the Forest Service in 1985 with the overarching goal of advancing understanding of how stream networks, watersheds, and entire landscapes respond to changes in streamflow, sediment transport, and wood entrainment. Over the course of his career he has studied a wide range of drivers of fluvial regimes, including responses to natural disturbances such as fire and volcanic eruptions, changes in forest land use, effects of dam construction or removal, river restoration, climate change, and the intrinsic evolution of geomorphic systems. While his earlier research focused almost exclusively on forested mountain landscapes in the Pacific Northwest, the geographical scope of his work now encompasses entire river systems, and directly addresses scales ranging from geological provinces (i.e., Cascade Mountains) to the western U.S. to international comparisons of river systems and management in diverse terranes. This work has included extended collaborations with research groups in Japan, China, and Italy. He is the designated U.S. representative for the U.S. China Bilateral Exchange for Natural Disasters with the Chinese Academy of Science’s Institute for Mountain Research and Environment in Chengdu, and co-chairs the Large Rivers Working Group of the International Association of Geomorphology. He is a former Deputy Editor and current Associate Editor for the journal Water Resources Research, a member of the national advisory committee for the Critical Zone Observatory Program, and a newly-elected GSA Fellow.

Ignacio Rodriguez-Iturbe, Princeton University Ignacio Rodriguez-Iturbe is the James S. McDonnell Distinguished University Professor of Civil and Environmental Engineering at Princeton University. The dynamics of the interaction between climate, soil, and vegetation are the main focus of Rodriguez-Iturbe's research group. These dynamics are crucially influenced by the scale at which the phenomena are studied as well as by the type of climate, the physiological characteristics of the vegetation, and the pedology of the soil. Moreover, not only the temporal aspects but also the spatial aspects of the dynamics are crucially dependent on these factors.

The intertwined hydrologic, ecologic, and geomorphologic dynamics are responsible for a large number of crucially important environmental variables. Thus channel networks act as ecological corridors playing an important role in the biodiversity of freshwater fish populations. Similarly, soil moisture and runoff are important hydrologic drivers impacting the spatially distributed habitat capacity controlling biodiversity of vegetation. At larger spatial scales, precipitation itself is influenced by the soil moisture present in the region and this phenomenon needs to be incorporated into the modeling scheme. At intermediate scales involving river basins, the geomorphologic characteristics of the drainage network is a commanding factor in the spatial organization of soil moisture. Rodriguez-Iturbe's group is trying to link the recent advances on the scaling characteristics of the network with the dynamics of the soil moisture and some related ecological processes. With the above framework the group hopes to elucidate some of the most fundamental issues of the climate-soil-vegetation interaction that lie at the heart of hydrology.

Professor Rodriguez-Iturbe has received numerous honors and awards throughout his career, the most recent being election to the National Academy of Sciences in spring 2010. He was awarded the Stockholm Water Prize in 2002, elected as a member of the National Academy of Engineering in 1988, and was the recipient of the AGU Horton Medal in 1998 and the William Bowie Medal in 2009. Rodriguez-Iturbe received his Civil Engineering degree from Universidad del Zulia in 1963, his MSc from the California Institute of Technology in 1965 and his PhD from Colorado State University in 1967.

Abstracts – Invited Speakers (Arranged in order of presentation and grouped by Session)

Abstracts – Invited Speakers

Title Index to Speaker Abstracts

Famiglietti — The human fingerprint on land-atmosphere interactions ...... 1 Maxwell — Development of a groundwater--atmospheric model and its use in diagnosing land-atmosphere interactions ...... 1 Parlange — Land - atmosphere interactions: field studies and simulations ...... 1 Kirchner — Hydrological processes revealed by high-frequency chemical dynamics spanning the periodic table ...... 2 Harvey — Ecologically relevant measures of groundwater-surface water interactions in flowing aquatic ecosystems ...... 2 Packman — Multi-scale solute and particle transport in rivers ...... 3 Kustas — Application of thermal remote sensing for multi-Scale estimation of evapotranspiration and drought ...... 4 Salvucci — The Bouchet-Morton Complementarity Hypothesis: An example of land-atmosphere coupling and an explanation of pan evaporation ...... 4 Troch — Hydrological partitioning, vegetation water use and climate sensitivity at catchment scales ...... 5 Haggerty — Surface water or hyporheic transient storage in streams - a false dichotomy? ...... 6 Krause — Hot moments in cold spots - Distributed sensor networks for investigating multi-component reactive transport processes at aquifer-river interfaces ...... 6 Genereux — Coupled water and nitrogen fluxes through a streambed in an agricultural watershed: measurements, patterns, controls ...... 7 Smerdon — Attempting to quantify fluxes across the water table: Gleaning some insight from modeling unsaturated flow in semi-arid and sub-humid regions ...... 9 Ng — Identifying land-surface controls on diffuse recharge: What we can learn by integrating model simulations and unsaturated zone data ...... 10 Loheide — The groundwater component of ET and the groundwater subsidy provided to vegetation: Equivalent quantities? ...... 10 Weiskel — Water-use regimes: Characterizing direct human interactions with the hydrosphere ...... 11 VanBriesen — Engineered and natural water systems: Sensing and modeling at the interfaces ...... 11 Minsker — Improving management of fluxes across the human-natural Interface: A real-time control system for combined sewer overflows ...... 12 McGuire — The concept of hydrological connectivity of hillslopes and streams: Open questions and ways forward ...... 13 Jencso — Controls on landscape hydrologic connectivity and riparian buffering: Implications of catchment structure for streamflow generation and source water dynamics ...... 13 Harman — Scaling up hydrologic predictions from heterogeneous soils to heterogeneous catchments challenges and new approaches ...... 13 Hirschboeck — Connecting flooding and climatic variability: What are the missing links? ...... 15 Krajewski — A diagnostic framework for the prediction of floods: The Iowa flood of June, 2008 ...... 15 Smith — The climatology of flooding for the United States east of the Rocky Mountains ...... 16 McNamara — Storage dynamics as a metric of catchment intercomparison ...... 17 Soulsby — Reconciling storage estimates in montane catchments: Hydrometric and tracer-based approaches in inter-catchment comparisons ...... 17 Bishop — Riparian zone control on stream dissolved organic carbon dynamics: Using storage to define the limits of DOC flushing during spring flood...... 17 Freifeld — Distributed thermal perturbation sensing for monitoring subsurface processes ...... 18 Lane — Use of distributed-temperature sensing systems by the U.S. Geological Survey ...... 18 Mondanos — Field deployment guidelines for distributed temperature sensing (DTS) systems ...... 19 Abstracts – Invited Speakers

Monday Morning Session 1A: The Atmosphere – Land Surface Interface

The human fingerprint on land-atmosphere interactions J. Famiglietti* and M. Lo, UC Center for Hydrologic Modeling, University of California, Irvine

In this study we establish the importance of groundwater in land surface memory, including its role in global-scale land surface-atmosphere interaction. The critical depths over which groundwater plays a key role are established, as are their impacts on the persistence of moisture anomalies, evapotranspiration, surface temperature, the atmospheric circulation, precipitation and feedbacks. Next we use data from the GRACE mission on trends in terrestrial water storage to identify regions of significant groundwater depletion, and explore the role of human water use on groundwater-driven land-atmosphere interactions. Implications for the impact of future water use on regional and global climate.

Development of a groundwater--atmospheric model and its use in diagnosing land-atmosphere interactions Reed M. Maxwell, Department of Geology and Geologic Engineering; Hydrologic Science and Engineering Program; International Groundwater Modeling Center, Colorado School of Mines, Golden, CO

Complete models of the hydrologic cycle have gained recent attention as research has shown interdependence between the coupled land and energy balance of the subsurface, land surface and lower-atmosphere. Here the coupling strategy behind “groundwater to atmospheric models” is discussed and two different models are presented, PF.WRF and PF.ARPS. These models are combinations of the of the Weather Research and Forecasting (WRF) and Advanced Regional Prediction System (ARPS) atmospheric models and ParFlow (PF) a parallel hydrology model that fully integrates three-dimensional, variably-saturated subsurface flow with overland flow. These models are coupled in an explicit, operator- splitting manner via the land surface model (LSM). The coupled model formulations will be presented and a very accurate balance of water between the subsurface, land surface and atmosphere is verified. A number of examples are then used to demonstrate the improvement in important physical processes afforded by the coupled models. These include idealized and semi-idealized simulations with multiple surface spin-ups and different microphysics parameterizations. These simulations illustrate enhancements to coupled model physics for a range of applications in water resources, hydrology and wind energy forecasting.

Land - atmosphere interactions: field studies and simulations Marc Parlange, Laboratory of Environmental Fluid Mechanics and Hydrology, École Polytechnique Fédérale de Lausanne, Lausanne Switzerland

Recent advances in Large Eddy Simulation (LES), distributed environmental sensors, and active remote sensing (lidar) are opening new opportunities to understand the interaction between the land and the atmosphere. This talk will present results from two field campaigns in the Swiss Plateau and the Swiss Alps. Lidar measurements of water vapor are used in the Tables experiment to understand Taylor's hypothesis and LES is applied to further study under ideal conditions. This is one of the fundamental assumptions used in all data analysis at the land-atmosphere interface and is studied experimentally and computationally. First results of Alpine sensor deployments at La Fouly catchment as related to air flow patterns is presented along with recent observations on snow - turbulence interactions. The talk will finish with new simulations of wind blown snow using LES and recent advances in the representation of mountain topography. The possibility to have simulations that are faithful to the air flow physics in Alpine environments encourages us to rethink how catchment hydrology forecasts might be run in the future.

Spk -1 Abstracts – Invited Speakers

Monday Morning Session 2A: The Groundwater – Surface Water Interface

Hydrological processes revealed by high-frequency chemical dynamics spanning the periodic table James W. Kirchner1,2* and Colin Neal3

1Swiss Federal Institute for Forest, Snow, and Landscape Research (WSL), Birmensdorf, Switzerland 2Swiss Federal Institute of Technology (ETH), Zürich, Switzerland 3Centre for Ecology and Hydrology, Wallingford, UK

Catchment tracer studies have typically suffered from a stark mismatch of measurement timescales: water fluxes are typically measured sub-hourly, but their chemical signatures are typically sampled only weekly or monthly. More intensive measurement campaigns usually last only for short periods, such as individual storm cycles. At the Plynlimon catchment in mid-Wales, however, precipitation and streamflow have now been sampled every seven hours for nearly two years, and analyzed for water isotopes and more than 40 chemical tracers spanning the periodic table.

Here we explore these unique tracer time series, and compare them to longer-term (~20 years) but less frequently sampled (weekly) hydrochemical data from the same catchment. The high-frequency sampling reveals clear diurnal cycles in many chemical species, including some that are not normally thought to be biologically controlled. Passive tracers such as chloride and water isotopes are very strongly damped in streamflow relative to precipitation, implying that the catchment stores and mixes volumes of water that are much larger than individual storms, on timescales that are much longer than the intervals between events. However, other chemical species show strong coupling to streamflow on timescales of hours, implying that the catchment can rapidly re-set the chemical signature of "old water" in response to changes in the flow regime. The implications of these observations for catchment flowpaths, runoff generation, and biogeochemical processes will be discussed.

Ecologically relevant measures of groundwater-surface water interactions in flowing aquatic ecosystems Jud Harvey, USGS, Reston, VA

Surface-subsurface water exchange occurs in all aquatic ecosystems, influencing remarkably similar hydroecological processes in diverse systems such as steep mountain streams, lowland rivers and floodplains, coastal wetlands, and subtidal marine ecosystems. Localized recharge of surface water from the aquatic ecosystems enter subsurface flow paths, bringing labile carbon and other energy-rich substrates into contact with high concentrations of microbes on sediments that stimulate organic matter decomposition. Discharge from those flow paths returns the products of decomposition, inorganic nutrients and other energy-rich compounds, back to surface water where they are utilized for primary production by algae and aquatic macrophytes. In this manner surface-subsurface exchange modulates aquatic ecosystem metabolism and sustains detrital-based components of food webs. The role of advection in delivering dissolved constituents to sites of reactions in aquatic sediments has grown to be appreciated following decades when the focus was on diffusion and bioturbation as the dominant transport processes. The challenge in characterizing advection across interfaces and its role in ecological processes stems from several factors. First, surface-subsurface water exchange involves more than just gravity and elevation components of the driving force, and may also include turbulence and mean velocity-driven components. In fast flowing channels the latter driving forces may easily dominate the former, thus vastly extending the range of processes that may need to be considered. Measurements are difficult because no single hydraulic approach encompasses all of the relevant physical processes. Nor is there a tracer approach, utilizing either an introduced tracer or tracer that is naturally present, which is sensitive to the entire distribution of spatial and temporal scales of surface-subsurface exchange that may be important. Second, the factors that determine driving forces and flow resistance vary at relatively small spatial scales (e.g. centimeters to tens of meters), whereas the cumulative effects on ecological processes are relevant at much larger scales (hundreds of meters to tens of kilometers). As a consequence, even the hydrology components of hydroecological models tend to be empirical with transport parameters that have little meaning outside of very specific circumstances. As an example, Spk -2 Abstracts – Invited Speakers

typical stream tracer experiments are analyzed using models with highly empirical parameters that cannot easily be transferred to other systems or adjusted to accommodate changing flow conditions. This presentation summarizes progress in improving prediction of surface-subsurface exchange and its relevance to ecological processes using 1) data synthesis from a variety of aquatic ecosystems (streams, rivers and floodplains and coastal wetlands), and 2) simple predictive models that unify essential physics with ecologically relevant biogeochemical reactions. An important goal is to improve the transferability of hydroecological simulations across changing flow and geomorphic conditions in aquatic ecosystems. Examples feature research that is designed to improve water management and restoration strategies to protect valued ecological functions of aquatic ecosystems as they respond to stresses imposed by changing land use.

Multi-scale solute and particle transport in rivers Aaron I. Packman1*, Judson W. Harvey2, Susa H. Stonedahl1, Antoine F. Aubeneau1, Jennifer Drummond1, and Anders Wörman3

1 Northwestern University, Department of Civil and Environmental Engineering, Evanston IL, USA 2 U.S. Geological Survey, National Research Program, Reston VA, USA 3 KTH Royal Institute of Technology, Division of Water Resources Engineering, Stockholm, Sweden

There is currently broad interest in understanding surface-groundwater interactions because of their importance to diverse processes such as carbon and nutrient dynamics, contaminant transport, and connectivity in river ecosystems. Recently, considerable progress has been made in understanding many individual mechanisms of both large-scale surface-groundwater interactions and more local-scale hyporheic exchange. However, the linkage of flows across this continuum is not well understood. Here we present a framework for assessing surface-subsurface interactions and induced hyporheic flow paths from the bedform scale to the reach scale, and use this approach to interpret multi-scale interactions. Small-scale features appear to dominate the overall interfacial flux, as has been suggested in prior studies, but rates and patterns of hyporheic exchange are substantially modified by larger-scale flows imposed by channel morphology and groundwater inputs. For example, reach-scale stream-groundwater interactions produce sequences of gaining and losing reaches that can suppress or enhance local-scale hyporheic exchange. The residence time of exchanged water generally increases with the size of the feature that induces it, leading to a wide distribution of residence times. Natural fluvial topography has fractal properties with defined scaling regimes, leading to broad, multi-scale surface-groundwater interactions that produce complex patterns in porewater flows. As a result, interfacial fluxes do not average in a simple fashion because of the competitive effects of flows induced at different scales, and it is not possible to estimate exchange simply by summing a series of independent process models. The broad range of exchange timescales also means that it is not possible to infer the full spectrum of exchange using a single experimental method. In particular, whole-stream tracer injection methods generally resolve only a narrow window of exchange timescales because of limitations associated with sampling frequency, measurement sensitivity, and experiment duration. This is especially problematic when in-stream measurements are used to infer non-conservative processes occurring at or beneath the streambed surface, such as nutrient uptake and fine particle capture. Subsurface measurements provide much greater sensitivity for longer timescales of exchange, but suffer from a limited ability to resolve heterogeneity in interfacial fluxes and porewater flows. The complexity of these process interactions requires careful consideration of the range of spatial and temporal scales that are relevant to the transport, retention, reaction, or consumption of any stream-borne solutes or particles of interest.

Spk -3 Abstracts – Invited Speakers

Monday Afternoon Session 1B: The Atmosphere – Land Surface Interface

Application of thermal remote sensing for multi-Scale estimation of evapotranspiration and drought William P. Kustas* and Martha C. Anderson, USDA-ARS, Hydrology and Remote Sensing Laboratory, Beltsville, MD

Thermal infrared (TIR) remote sensing of land-surface temperature (LST) provides valuable information about the sub-surface moisture status affecting evapotranspiration and detecting the onset and severity of drought. While empirical indices measuring anomalies in LST and vegetation amount (e.g., as quantified by the Normalized Difference Vegetation Index; NDVI) have demonstrated utility in monitoring ET and drought conditions over large areas, they may provide ambiguous results when other factors (radiation, advection, air temperature) are affecting plant stress. A more physically based interpretation of LST and NDVI and their relationship to surface and sub-surface moisture conditions can be obtained with a surface energy balance model that considers soil and vegetative canopy radiation and turbulent exchange driven by TIR remote sensing. This approach, the Atmosphere-Land Exchange Inverse (ALEXI) model, couples a two-source (soil + canopy) land-surface model with an atmospheric boundary layer model in time-differencing mode to routinely and robustly map fluxes across the U.S. continent at 5- 10 km resolution using thermal band imagery from the Geostationary Operational Environmental Satellites (GOES). The moisture stress is quantified in terms of the reduction of evapotranspiration (ET) from the potential rate (PET) expected under non-moisture limiting conditions. A derived Evaporative Stress Index (ESI), given by anomalies in 1-ET/PET, shows good correspondence with standard drought metrics and with patterns of antecedent precipitation, but at significantly higher spatial resolution due to limited reliance on ground observations. Higher resolution drought and ET assessments can be generated through spatial disaggregation scheme (DisALEXI) using TIR data from polar orbiting instruments such as Landsat (60-120m) and MODIS (1km). This allows monitoring of ET at the sub- watershed and field scales, and moreover permits validation of the ET product using tower-based flux observations. The ALEXI algorithm is diagnostic and does not require precipitation or soil texture information, unlike most other physically-based ET models. This is a significant advantage for monitoring many areas where such information is not locally available, particularly precipitation which often must be extrapolated from a sparse observation network. It has also prompted the development of assimilation schemes using ALEXI model output of ET and a soil moisture proxy to constrain water balance-SVAT model predictions.

The Bouchet-Morton Complementarity Hypothesis: An example of land-atmosphere coupling and an explanation of pan evaporation Guido D. Salvucci, Boston University

Archived global measurements of water loss from evaporation pans constitute an important indirect measure of evaporative flux. Historical data from evaporation pans shows a decreasing trend over the last half century, but the relationship between pan evaporation and moisture-limited terrestrial evaporation is complex, leading to ambiguities in the interpretation of this data. Under energy-limited conditions, pan evaporation (Epan) and moisture-limited terrestrial evaporation (E) increase or decrease together, while in moisture-limited conditions these fluxes form a complementary relation in which increases in one rate accompany decreases in the other. This has lead to debate about the meaning of the observed trends in the context of changing climate. Here a two-dimensional numerical model of a wet pan in a drying landscape is used to demonstrate that, over a wide range of realistic atmospheric and surface conditions, the influence that changes in E have on Epan (1) are complementary and linear, (2) do not depend upon surface wind speed, and (3) are strikingly asymmetrical, in that a unit decrease in E causes approximately a five-fold increase in Epan, as found in a recent analysis of daily evaporation from US grasslands (Kahler and Brutsaert, 2006). Previous attempts to explain the CR have been based on one dimensional diffusion and energy balance arguments, leading to analytic solutions based on Penman-type bulk difference equations. But without acknowledging the spatially complex two dimensional humidity and temperature field around the pan, and specifically how these fields change as the contrast between the wet pan and the drying land surface increases, such integrated bulk difference equations are a priori

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incomplete (they ignore important divergence terms), and thus these explanations must be considered physically incomplete. Results of the present study improve the theoretical foundation of the CR, thus increasing the reliability with which it can be applied to estimate water balance and to understand the pan evaporation record of climate change.

Hydrological partitioning, vegetation water use and climate sensitivity at catchment scales Peter Troch, Department of Hydrology and Water Resources, The University of Arizona

This presentation reviews results from the UIUC Hydrologic Synthesis Summer Institute held at the University of British Columbia in Vancouver during the summer of 2009. One of the themes at the Summer Institute was “Hydrosphere and biosphere interactions” and several students and faculty mentors worked together to investigate spatial and temporal patterns in hydrological partitioning, vegetation water use and climate sensitivity in catchments across the conterminous US. We adopted the theoretical framework pioneered by L’vovich (1979), and subsequently extended by Ponce and Shetty (1995a,b), to analyze annual water balance variability: (i) regional (between-catchment) variability of mean annual water balances, and (ii) between-year (inter-annual) variability in selected individual catchments, and the symmetry between the two. This involved analysis of the annual water balance in terms of a two-stage partitioning, firstly, of annual precipitation into quick flow and soil wetting, and subsequently, of the resulting soil wetting into slow flow and vaporization (i.e., evaporation + transpiration). We fitted theoretical relationships suggested by Ponce and Shetty (1995a,b) to the partitioning at each stage, producing expressions for the three components of quick flow, slow flow and vaporization. The associated parameter values for 377 catchments exhibited coherent regional patterns. Conversion of the Ponce and Shetty-type analytical relationships into non-dimensional forms showed that the partitioning at each stage can be expressed as a competition between alternative catchment functions, the form of which appears to be universal. They indicate that the spatial heterogeneity of water balance partitioning amongst the MOPEX catchments is underlain by a parameter-free universal relationship that is transferable regionally. Key non-dimensional similarity parameters are identified that then serve to connect this invariant regional relationship to site-specific response characteristics. Our analyses have highlighted a close symmetry between spatial (regional) variability of mean annual water balances and general trends of temporal (inter-annual) variability in individual catchments. The L’vovich- Ponce-Shetty theory can thus be the basis for data-based assessments of hydrologic similarity, and to assist with predictions of the effects of long-term climate variability and change, through providing a theoretical framework for "space for time" substitutions. Using the Ponce and Shetty models we derived streamflow, quick flow and slow flow sensitivities to precipitation change. Our analysis revealed that these sensitivities are function of the average catchment-scale water use efficiency as quantified by the Horton index (Troch et al., 2009). This interesting result links inter-annual variability of all runoff components to long-term hydrologic functionality related to climate, vegetation, soil and topography.

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Monday Afternoon Session 2B: The Groundwater – Surface Water Interface

Surface water or hyporheic transient storage in streams - a false dichotomy? Roy Haggerty1*, Alba Argerich1, and Eugènia Martí2

1Department of Geosciences, Oregon State University, Corvallis, OR 2Limnology Group, Centre d'Estudis Avançats de Blanes, Consejo Superior de Investigaciones Científicas, Blanes, Spain

Hydrologists and stream ecologists have spent considerable effort understanding transient storage in streams. Some of this effort, particularly by hydrologists, and including the first author of this abstract, has focused on understanding how much transient storage exists in the surface and hyporheic compartments. This has been and will continue to be helpful because surface transient storage (STS) and hyporheic transient storage (HTS) are physically distinct. However, transient storage is primarily important because of its biogeochemical properties – as a source/sink for nutrients and other important chemical species, and because of its ability to transform these as well as pollutants. We propose that another way to look at transient storage is to divide it into zones that are biogeochemically active and relatively inactive. We refer to these as metabolically active transient storage (MATS) and metabolically inactive transient storage (MITS). For example, the benthic zone of STS and the near-surface HTS may be biogeochemically very similar as MATS, although their physics are quite different. Similarly, the water column within STS and the downstream part of HTS flowpaths may both be MITS, at least in terms of aerobic metabolism.

We have developed a tracer to investigate and measure MATS. The tracer is resazurin (“Raz”), which is a weakly-fluorescent redox-sensitive phenoxazine compound that undergoes an irreversible reaction to resorufin (“Rru”) in the presence of aerobic metabolism. We have conducted 7 field tracer tests with Raz and have characterized many of its properties as a tracer. We are now moving toward using Raz to learn about streams in ways that have not previously been possible. For example, we have found in a comparison of two reaches of a stream in the HJ Andrews Experimental Forest, that a reach with only STS has very active MATS but there is very little total MATS volume. Consequently, the overall metabolism in this reach is low. In an adjacent reach with large HTS has a much less active MATS. Because of the large HTS, however, the overall metabolism in the reach is higher than in the STS- dominated reach.

Results from this and other experiments will be shown that show the current capabilities with the new tracer.

Hot moments in cold spots - Distributed sensor networks for investigating multi-component reactive transport processes at aquifer-river interfaces Stefan Krause, Earth Science and Geography Department, Keele University, Keele, UK

The mixing of groundwater and surface water in hyporheic zones, with often increased redox-reactivity and chemical transformation rates, can have substantial impact on the transformation of solutes transported over the aquifer-river interface. Depending on redox-status and reaction types, hyporheic mixing of groundwater and surface water can lead to either attenuation or enrichment of pollutants and nutrients with diametrical implications for stream and aquifer hydro-ecological conditions.

Here we present the combined application of distributed sensor networks, in-stream geophysical exploration techniques and multi-scale approaches of hyporheic pore water sampling for investigating multi-component reactive transport of nitrate and a chlorinated solvent (Trichloroethylene - TCE) at the aquifer-river interface of a UK lowland river.

Spatial patterns of hyporheic redox-conditions, dissolved oxygen and organic carbon content as well as concentrations of major anions, TCE and its decay products have been observed in 48 nested multi-level mini piezometers and passive gel probe samplers. The hyporheic pore water sampling identified hot spots of increased nitrate attenuation beneath semi-confining peat lenses in the streambed which appeared to

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coincide with increased TCE breakdown and decay. The intensity of concentration changes underneath the confining peat pockets has been found to correlate with the state of anoxia in the pore water as well as the supply of organic carbon and hyporheic residence times. In contrast, at locations where flow inhibiting peat layers were absent or disrupted – fast exchange between aquifer and river caused a break through of nitrate without significant concentration changes along the hyporheic flow path.

In order to identify the spatial patterns of reactivity hot spots in the streambed, distributed temperature sensor networks and hydro-geophysical exploration methods have been applied to identify the structural streambed heterogeneity including location and extend of flow inhibiting structures and to trace the exchange flow patterns between groundwater and surface water. At focus areas characterising representative streambed geomorphic features, the complex spatial distribution of highly conductive sandy and gravely sediments in contrast to semi-confining, low conductivity peat lenses has been identified by in-stream ground penetrating radar. Reach scale spatial patterns and temporal dynamics of aquifer-river exchange fluxes have been analysed by heat tracer experiments based on Fibre-Optic Distributed Temperature Sensing (FO-DTS) in combination with 2D thermocouple arrays and a small scale heat pulse injection methods for tracing shallow (25 cm) hyporheic flow paths. Temperature survey results indicate that during summer, patterns of cold spots in the investigated streambed sediments can be attributed to fast groundwater up-welling in sandy and gravely sediments resulting in low hyporheic residence times. Contrasting conditions were found at warmer areas at the streambed surface where groundwater – surface water exchange was inhibited by the existence of peat or clay lenses within the streambed. FO-DTS observations of regional groundwater up-welling patterns were complemented by heat pulse injection experiments which provided essential information of the shallow (< 25 cm) aquifer- river exchange fluxes.

The investigations supported the development of a conceptual model of aquifer - river exchange and hyporheic reactivity in lowland rivers including temperature traceable “hyporheic super-reactors” of great importance for river restoration, water quality and ecology status.

Coupled water and nitrogen fluxes through a streambed in an agricultural watershed: measurements, patterns, controls David Genereux1*, Casey Kennedy2, Helena Mitasova1, D. Reide Corbett3

1 Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University 2 Department of Earth and Atmospheric Sciences, Purdue University 3 Department of Geological Sciences and Institute for Coastal Science and Policy, East Carolina University

We studied the coupled water and nitrogen (N) fluxes through a streambed in an agricultural watershed in North Carolina. Over a year we returned bimonthly to 46 streambed points to measure hydraulic conductivity (K) and vertical head gradient (J) in the streambed, and collect streambed groundwater - + (below the depth of penetration of surface water) for analysis of N species (TDN, NO3 , NH4 , DON) and other solutes. Water and N fluxes through the streambed were calculated as v = KJ and fN = v[N], respectively, where [N] is the groundwater concentration of an N species. For each bimonthly run, we interpolated among the point values to produce raster maps of v, fN, and related variables in the streambed, and integrated over the interpolated surfaces to quantify net fluxes of N and water into the reach. Mean K, J, and v were 18 m/d, 0.046, and 0.51 m/d, respectively. TDN flux through the streambed -2 -1 -2 -1 was equal to fNO3 (mean = 154 mmol m day ) plus fDON (mean = 17 mmol m day ); ammonium was negligible. Localized zones of high and low fNO3 changed size and shape over the study year but - remained in basically the same locations (the same was true of K, J, and [NO3 ]). Temporal variability in - fNO3 was controlled largely by changes in v rather than changes in [NO3 ]. Changes in v were in turn caused by temporal variation in both J and K (K, not only J, varied over time). The physical variables K, J, and v were symmetrically distributed across the channel; J was lowest in the center where K and v were highest. Higher K in the center of the channel seemed to focus groundwater discharge there. However, N concentrations and fluxes were not symmetrically distributed across the channel; on average, they were lowest in the center (where v was highest) and highest on the left side. To explore this asymmetry, we repeated the measurements described above along with simultaneous measurements of dissolved gases in the streambed groundwater: Ar and N2 to estimate “excess air” and excess N2 from denitrification, and

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CFCs to estimate groundwater age. We found a band of greater groundwater age in the center of the - channel, coinciding with bands of lower groundwater [NO3 ] and fNO3 that were due to the discharge of older, less-contaminated groundwater (not greater denitrification) in the center of the channel. However, - denitrification contributed to the asymmetry of [NO3 ] and fNO3, lower values of which occurred on the right side in association with greater denitrification on the right. Discharge to streams and denitrification - represent roughly equal sinks for groundwater NO3 at the site. Finally, v and age (τ) at the same points allowed estimation of the mean transit time (MTT) of the groundwater discharging to the stream reach, as the flow-weighted mean age of the groundwater: MTT = Στν/Σν = 30 yr. A more complicated spatial interpolation and integration procedure gave essentially the same result. This MTT value may be an overestimate if, as we suspect, sampling missed some shallow young groundwater discharge near the waterline.

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Tuesday Morning Session 3: The Land Surface – Groundwater Interface

Attempting to quantify fluxes across the water table: Gleaning some insight from modeling unsaturated flow in semi-arid and sub-humid regions Brian D. Smerdon1*, Jaime J. Carrera-Hernández2, Carl A. Mendoza3, and Diana M. Allen4

1 CSIRO Land and Water, Waite Campus, South Australia, Australia 2 Institute for Scientific and Technological Research, San Luis Potosi, Mexico 3 University of Alberta, Department of Earth and Atmospheric Sciences, Alberta, Canada 4 Simon Fraser University, Department of Earth Sciences, British Columbia, Canada

Different techniques have been used to quantify the rate of groundwater recharge, including direct physical measurements (e.g. lysimeters, soil moisture profiles, fluctuations in the water table) and interpretation of naturally occurring and applied tracers (e.g. isotopic, solute, heat). For specific areas, these techniques have been proven to describe the physical process governing groundwater recharge very well. However, at broader-scales, upscaling techniques rely on mathematical models to quantify the spatial and temporal dynamics of the recharge process. Such modeling approaches advance the ability to predict water fluxes across the water table, but require adequate representation of moisture migration through the unsaturated zone in combination with variables readily acquired at large spatial scales. This presentation focuses on unsaturated flow modeling using Richards’ equation to estimate fluxes across the water table, and some of the underlying choices when attempting to develop such models.

First, factors that govern the ‘calculation’ of flux rates in Richards’ equation-based models are investigated. Numerical experiments illustrate the effect of numerical model discretization and boundary condition selection on predicting fluxes across the water table. These experiments are based on hypothetical one-dimensional, monolithic soil columns having water table depths of 2, 4, 6, and 12 m. The investigation centers on a sub-humid forested region, where the climatic record contains periods of wet and dry cycles. Transient simulation of water fluxes requires that vertical discretization toward the upper and lower boundary of the model columns be spaced at 0.001 m and gradually increase to a spacing of 0.1 m within the middle of the model column. Furthermore, it is illustrated that a specified-head lower boundary condition is preferred over a unit-gradient approach, to facilitate discharge from the water table during extended dry conditions.

Second, factors that govern the ‘context’ of estimating fluxes within broad regions are discussed. Spatially distributed rates of recharge and actual evapotranspiration are estimated for a semi-arid region using different treatments of meteorological input data (a single climate station vs. gridded climate surface) and different basis for reference evapotranspiration (Thornthwaite vs. Penman-Monteith). The selection of these data are shown to have a greater influence on estimating flux across the water table during wet periods when recharge occurs, compared to dry periods when discharge from the water table is dominant. Although the difference between results is subtle when compared at seasonal timeframes, findings reveal that the additional spatial elements included with a gridded climate surface help define recharge rates across a larger-scale.

Investigating these ‘calculation’ and ‘context’ factors provides some general guidance on the application of unsaturated flow models to quantify fluxes across the water table. While the modeling approaches require parameterization, some insight of the underlying processes may be gleaned from simulation, especially when combined with physical measurements and tracers.

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Identifying land-surface controls on diffuse recharge: What we can learn by integrating model simulations and unsaturated zone data Gene-Hua Crystal Ng1*, Dennis McLaughlin2, Dara Entekhabi2, Bridget R Scanlon3

1U.S. Geological Survey, Menlo Park, CA 2Department of Civil and Environmental Engineering, MIT, Cambridge, MA 3Bureau of Economic Geology, Jackson School of Geosciences, University of Texas at Austin, Austin, TX

Unsaturated zone modeling provides a powerful means for probing connections between land-surface controls and recharge. Unlike observations, models are not hampered by limitations in spatial or temporal coverage, and thus, they can in theory provide complete analyses of land surface-groundwater interactions. However, in semiarid environments, where groundwater resources may be most critical, precipitation and evapotranspiration nearly balance. This makes numerical models of diffuse recharge highly sensitive to model errors. Natural chloride concentrations in the unsaturated zone provide more robust indicators of low recharge rates, but they yield estimates at coarse time scales that can mask most control mechanisms. This talk presents a data assimilation framework that combines model predictions and chloride-based estimates to use the advantages of both methods. The model-data integration approach produces probabilistic distributions of soil and vegetation parameters and time series of potential recharge. An application of this approach is shown for rain-fed agricultural study sites in the U.S. southern High Plains. The data assimilation results demonstrate that recharge at the sites occurs episodically, and it is produced only when certain meteorological and vegetation conditions coincide. Data assimilation methods that combine modeling and chloride observations provide the high temporal resolution information needed to identify mechanisms controlling diffuse recharge and offer a way to examine the effects of land use and climatic variability on groundwater resources.

The groundwater component of ET and the groundwater subsidy provided to vegetation: Equivalent quantities? Steven Loheide, Department of Civil and Environmental Engineering, University of Wisconsin

For more than a century it has been recognized that phreatophytic vegetation uses and benefits from shallow groundwater. Diurnal water table fluctuations are a common feature of well hydrographs recorded in wetlands, riparian areas, and similar groundwater dependent ecosystems. This periodic signal can be used to estimate the groundwater consumption (ETG) by phreatophytic vegetation, which is defined as the portion of total evapotranspiration that comes directly from groundwater. Our research shows that ETG can be quantified at sub hourly time scales by exploiting the observed rates of water table declines during transpiration (daylight) periods while carefully accounting for recovery fluxes that are observable during non-transpiration (nighttime) periods. Quantifying ETG is important from a water resources perspective because this is the loss term from the groundwater system; however, ETG may not be the critical quantity from the vegetation perspective. We instead propose the concept of a groundwater subsidy (GWsubsidy) to plants, which is defined as the additional water available for root water uptake due to shallow water table conditions. Unlike ETG, the concept of GWsubsidy is not intended to quantify water extracted solely from the phreatic zone but rather to quantify additional root water uptake within the phreatic zone, capillary fringe and vadose zone, which is made available by shallow groundwater conditions. While plants may be consuming groundwater, this water is not considered a subsidy unless or until the water would be unavailable if not for the presence of shallow groundwater. Additionally, vadose zone water used by plants that would not be available except for the influence of the nearby water table is included in the GWsubsidy term. Through variably-saturated modeling, we were able to quantify the GWsubsidy by comparing the difference in root water uptake between a case with a specified water table regime and one with free drainage. This newly defined GWsubsidy better quantifies the benefit plants receive from shallow groundwater whereas the more traditionally estimated ETG quantifies the movement of water across the water table due to plant water use. When GWsubsidy and ETG are evaluated together, a more complete description of the ecohydrology of groundwater dependent ecosystems is revealed.

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Tuesday Morning Session 4: The Natural System – Human System Interface

Water-use regimes: Characterizing direct human interactions with the hydrosphere Peter K. Weiskel, USGS, Northborough, MA

Humans interact with hydrologic systems both directly and indirectly. Direct interactions include water withdrawals and return flows, whereby water is exchanged between natural water systems (aquifers and stream basins) and human water and wastewater infrastructure. Indirect interactions include processes and activities such as anthropogenic climate change, dam construction, stream channelization, and land- cover change (urbanization, deforestation, agricultural development, and wetland filling), among many others. To characterize direct human interactions with hydrologic systems in a comprehensive way, the water-use regime indicator framework has been developed. In contrast to scalar indicators of anthropogenic water stress in the literature, the water-use regime is a two-dimensional, vector indicator that defines human-induced hydrologic stress in terms of four possible end-members: (1) depleted (where human withdrawals dominate all outflows from a hydrologic system); (2) surcharged (human return flows and imports dominate system inflows); (3) churned (human flows dominate both inflows and outflows from a system); and (4) natural-flow-dominated (no human water use). The water-use regime of system during any time period of interest may be specified by a position on an x-y plot of normalized human inflows vs. outflows, where the corners of the plot denote the four end-member regimes. Examples of developed hydrologic systems that approach end-member water-use regimes are presented and discussed, including the California Central Valley Aquifer (churned); the Yellow River Basin (depleted); and aquifers receiving large volumes of irrigation return flow from imported surface water (surcharged).

Engineered and natural water systems: Sensing and modeling at the interfaces Jeanne M. VanBriesen, Department of Civil and Environmental Engineering and Center for Water Quality in Urban Environmental Systems (Water-QUEST), Carnegie Mellon University

Water is a central actor in engineered and natural systems. It moves through pores, channels and the atmosphere under the influence of natural physical processes as well as those that are engineered for control and management of quantity and quality. Drinking water and wastewater treatment plants are sited on riverbanks, while collection and distribution systems trace paths under our cities. Water moves in and out of these systems in ways that are complex and sometimes difficult to predict. In many older cities, sewers overflow regularly during rainfall events, leading to direct discharge from engineered collection systems into natural waterways. Drinking water distributions systems, too, suffer from significant leaks due to their age, leading to transfer of treated chlorinated drinking water to the subsurface, to streams and creeks, or sometimes directly to wastewater pipes.

Thus, urban water systems are complex systems-of-systems, with natural water flow and engineered water flow interacting through multiple connections. In all parts of the coupled engineered-natural water cycle, water quality changes along with quantity – again, through natural or engineered transformations, some achieved through significant energy investments.

While many engineered systems are extensively monitored to ensure adequate water and wastewater treatment as well as to manage the flooding and flows, the points at which the natural and engineered water systems interact are often poorly assessed. For example, most wastewater collection systems do not monitor overflow points to know when overflows occur, or how much wastewater is released. Drinking water systems often have only grab sample data for quality at locations within the distribution system far from the plant. It is critical that sensor networks being deployed throughout natural water systems also consider the potential for engineered water system sensing. Engineered systems deserve monitoring for the inherent value in managing water that is on its way to people and wastewater that must be treated before release to the environment. But, engineered system sensing can also serve another purpose. Engineered systems often sit at interfaces. Thus, data collected at drinking water intake locations on the quality of the source water is also data that can be used to understand that natural water system.

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The present talk will detail our work with deployment of sensors in drinking water distribution systems and integration of these data into operational control and management. Also discussed will be a sensor network deployed at multiple drinking water intakes on the Monongahela River in collaboration with the River Alert Information Network (RAIN) to create a sensor network for early warning of contamination events. Eventually sensor network data will be integrated through coupled models of the watershed and the water treatment and distribution systems.

Improving management of fluxes across the human-natural Interface: A real-time control system for combined sewer overflows Barbara Minsker1*, Andrea Zimmer1, Art Schmidt1, and Avi Ostfeld2

1Department of Civil & Environmental Engineering, University of Illinois Urbana-Champaign 2Technion University, Israel

The potential for real-time cyberinfrastructure, modeling, and decision support systems to improve management of fluxes across the human-natural interface is demonstrated for a case study examining combined sewer overflows along the North Branch of the Chicago River. To dynamically optimize complex sewer hydraulics, a generalized stepwise steady hydraulic model is coupled with a genetic algorithm (GA) to minimize overflow volume while using constraints to ensure that hydraulic transients do not occur. Sluice gate positions that direct potential CSOs into a deep tunnel instead of the waterway as well as a treatment plant pumping rate that alleviates interceptor pressure constitute the management decisions that affect CSO volume. Several approaches for improving computational performance of the online control system are evaluated to enable new strategies to be presented to operators every 15 minutes as storms unfold, considering a sliding two-hour forecasting window.

An advanced information system for real-time decision making will also be presented as an example of cyberinfrastructure that enables easier implementation of this type of real-time application. The system supports real-time geospatial visual analytics through a loosely-coupled, reconfigurable service-oriented architecture. A user-friendly and interactive Web 2.0 AJAX interface is supported by a data and workflow layer that provide support for streaming data fetching and indexing services, workflow services with model integration, virtual sensor services, provenance management, and virtual machine hosting.

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Tuesday Afternoon Session 5: The Transition Zone Between Hillslopes and Channels

The concept of hydrological connectivity of hillslopes and streams: Open questions and ways forward Kevin J. McGuire, Virginia Water Resources Research Center, Virginia Tech

The production of runoff from hillslopes is widely recognized as an important contributor to streamflow generation; however, processes that control how, when, and to what extent hillslopes connect to streams remain unclear. The term hydrological connectivity is increasingly found in the hydrology literature, yet there is lack of consensus on what connectivity is and how it relates to physical processes and field observations. The hydrological connection of hillslopes to the stream network is regarded as one of the key controls in determining catchment runoff response and has also been theorized to influence the export of solutes from uplands to streams. This talk will explore how hydrological connectivity in catchment hydrology is being used to develop conceptualizations of runoff sources and processes. Examples will be drawn from observations of hydrometric, stable isotope, and applied tracer responses and used to suggest considerations for future research on this topic.

Controls on landscape hydrologic connectivity and riparian buffering: Implications of catchment structure for streamflow generation and source water dynamics Kelsey Jencso, Montana State University

Hydrologic connectivity between catchment upland and near stream areas is essential for the transmission of water and solutes to streams. However, our current understanding of factors affecting hydrologic connectivity and the role of riparian zones in mediating the catchment scale export of water and solutes is limited. We tested the relationships between catchment topography, the duration of hillslope-riparian-stream (HRS) hydrologic connectivity, and the rate and degree of riparian shallow groundwater turnover along HRS well transects within a set of nested mountain catchments (Tenderfoot Creek Experimental Forest, MT). Transect HRS water table connectivity ranged from 0 to 100 percent of the year as a function of hillslope upslope accumulated area. During the annual snowmelt hydrograph hillslope water was always characterized by low specific conductance (~27 µS cm-1). In transects with transient hillslope water tables, riparian groundwater SC was elevated during baseflow conditions (~127 µS cm-1), but shifted towards hillslope signatures once a HRS groundwater connection was established. The degree of riparian groundwater turnover was proportional to the duration of HRS connectivity and inversely related to the riparian: hillslope area ratios. We applied this relationship to the stream network in 7 nested catchments within the TCEF and compared their turnover distributions to source water contributions measured at each catchment outlet. The amount of riparian groundwater exiting each of the 7 catchments was linearly related (r2 = 0.92) to the median riparian turnover time. Our observations suggest that the size and spatial arrangement of hillslope and riparian zones along a stream network and the timing and duration of groundwater connectivity between them is a first order control on the magnitude and timing of water and solutes observed at the catchment outlet.

Scaling up hydrologic predictions from heterogeneous soils to heterogeneous catchments challenges and new approaches Ciaran Harman* and Siva Sivapalan, Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign

Despite their central importance to hillslope hydrology, predictions of hillslope discharge to streams that are right "for the right reasons" have proved exceedingly difficult. Finding an appropriate, general framework for doing so would have a transformative impact on hydrologic forecasting of stream flow; water supply; and fluxes of pollutants, nutrients, pathogens and sediment. A primary obstacle to such predictions is the heterogeneity in landscape properties within a hillslope, and its interaction with the boundary conditions operating on the hillslope, such as the spatiotemporally varying climatic inputs, and connection to receiving landscape units. In this talk I will discuss recent progress towards an understanding of these interactions in saturated subsurface lateral flow. In particular I will discuss A) efforts to develop a similarity framework that can be used to understand the relative roles of internal

Spk -13 Abstracts – Invited Speakers structure and boundary conditions in controlling hillslope dynamics B) observations of the role of internal heterogeneity in controlling transient discharge from hillslopes and C) efforts to develop an upscaled model of hillslope flows that accounts for the effects of heterogeneity based on a continuous time random walk (CTRW).

The importance of understanding the landscape as a dynamic filter of hydrologic variability will be emphasized. The physical structure of landscapes, including unresolved spatial heterogeneity, alters the variability of water flows generated by the precipitation in a manner analogous to a (non-linear, but sometimes nearly linear) signal filter. This is the origin of unit hydrograph and other linearized approaches to runoff prediction. However, in certain circumstances of subsurface lateral flow, the flow itself is able to generate potential gradients that alter the local flow direction towards areas of high conductivity, and these lead to the reorganization of flowpaths through the hillslope as a whole. It is shown that this reorganization makes the hillslope response highly sensitive to the connection with the downslope boundary (as expressed in the boundary condition), and reduces our ability to make inferences about the variability of residence times in the hillslope from the discharge signal alone.

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Tuesday Afternoon Session 6: Advances in the Understanding of Floods

Connecting flooding and climatic variability: What are the missing links? Katherine K. Hirschboeck, The University of Arizona

Recent reports synthesizing the science of ongoing climate change have projected that due to rising global mean temperatures, “a higher fraction of rainfall will fall in the form of heavy precipitation, increasing the risk of flooding…” (Advancing the Science of Climate Change, National Research Council 2010). While increasing trends in extreme precipitation in the United States and elsewhere have been observed, it is unclear whether similar trends have occurred in extreme flooding. Some studies have not identified any systematic trends in peak streamflow, while others have found trends in some watersheds but not others. This lack of a systematic correspondence between changing precipitation extremes and flooding extremes has been attributed to many factors, including the overriding effects of land use changes, stream channel adjustments, issues related to record length, or basin scale. An additional explanation is that the relationship between flooding variability and climatic variability may need to be explored in new ways to identify connections that exist.

This presentation offers five insights on ways to identify flood-climate linkages that might be missed when using other analytical approaches: (1) Our understanding of climate and its variability should be expanded beyond statistical definitions and indices (e.g., average weather, shifting means, ENSO) to include a suite of process-based information, such as that proposed by Harman and Winkler (1991) “the study of climate from the viewpoint of its constituent weather components or events and the way in which these components are related to atmospheric circulation at all scales.” (2) This expanded understanding of climate can be linked both deterministically and probabilistically to flooding through a process-sensitive “bottom up” approach in which individual peaks are grouped according to their flood-causing storm types and circulation patterns. This approach highlights the underlying physical reasons for flood variations in specific watersheds, defines how mixed flood distributions and outlier events may be linked to climate, and challenges the underlying "iid" assumption that flood peaks are independently, identically distributed. (3) A deeper understanding of flood-climate linkages can be obtained by examining all observed flood peaks at a given gauge (e.g., the peaks-above-base record), not just the annual flood series. For example, climate variability may manifest itself in a shift to more frequent, smaller floods in a given year which would be missed due to an overemphasis on the annual or most extreme floods. (4) Watersheds located in transition zones between climate regions, or at the margins of influence by a specific storm type are likely to exhibit the greatest sensitivity to climatic variability. (5) The dominant flood-producing storm type can vary with basin size and topographic influence, resulting in a varied response to climatic variability depending on a basin’s scale and hierarchical position. Studies which have used one or more of these insights to identify linkages between climatic variability and flooding will be highlighted and preliminary mapping of watersheds and regions in the United States that are likely to be especially sensitive to climatic variability will be presented.

A diagnostic framework for the prediction of floods: The Iowa flood of June, 2008 Witold F. Krajewski1*, Ricardo Mantilla1, Vijay K. Gupta2, Luciana Cunha1

1IIHR-Hydroscience & Engineering, University of Iowa 2Department of Civil and Environmental Engineering, University of Colorado

Skilful prediction of floods across an array of spatial scales and for temporal scales ranging from real-time to decadal requires hydrologic models with correct but parsimonious representation of the dominant processes. Such representation will eliminate the need for calibration of the models that is widespread in the hydrology literature. We explain a nonlinear geophysical flood theory that is built on a diagnostic framework. It incorporates the role of space-time rainfall intensity, runoff generation, and water transport in the drainage network as three distinct and dominant aspects of flood genesis. The framework uses the observed power law, or scaling, relationship, of peak flows with respect to drainage area as the main diagnostic tool. We will illustrate the diagnostic concept using the 2008 Eastern Iowa floods and discuss development of flood forecasting models underway at the Iowa Flood Center. These models investigate the effect of different conceptual schemes of water delivery from hillslopes to channels of the river

Spk -15 Abstracts – Invited Speakers

network that include storage capacity, infiltration thresholds, and delay aspects, because a geophysical understanding of runoff generation is in a research stage. The main conclusion from the study is that the model is capable of reproducing not only the outlet hydrograph but also the scaling behavior of the peak flows at other observed locations within the Iowa River basin by parameterizing physically relevant features and without resorting to parameter calibration.

The climatology of flooding for the United States east of the Rocky Mountains James A. Smith, Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ

Flooding in the US east of the Rocky Mountains reflects a mixture of flood generating mechanisms, with extratropical systems and landfalling tropical cyclones playing central roles. We examine the climatology of heavy rainfall and flood magnitudes for the region through analyses of long rainfall and flood peak records and through case study analyses of major flood episodes. Spatial heterogeneities in flood peak distributions due to orographic precipitation mechanisms in mountainous terrain, coastal circulations near land-ocean boundaries and urbanization impacts on regional climate are central elements of flood peak distributions. Lagrangian analyses of rainfall distribution and storm evolution are presented for major flood events and used to motivate new directions for modeling of spatial extremes of flood peak magnitudes. Tropical cyclones are an important element of the upper tail of flood peak distributions throughout the eastern US, but their relative importance varies widely, and abruptly, in space over the region. Some of the largest rainfall accumulations in the world for time periods less than 6 hours are from orographic thunderstorm systems in the central Appalachian region. Warm season thunderstorm systems, and their alteration by the urban heat island, urban canopy and urban aerosols, are principal flood agents for urban environments throughout the study region. Analyses of flood frequency for the study region provide useful insights to emerging problems in flood science due to the range of flood mechanisms in the region and the extraordinary density of long-term stream gaging records maintained by the US Geological Survey.

Spk -16 Abstracts – Invited Speakers

Wednesday Morning Session 7: Catchment Comparison

Storage dynamics as a metric of catchment intercomparison Jim McNamara, Boise State University

Further advances in catchment hydrology hinge on establishing meaningful metrics for catchment inter- comparison to somehow make sense of the wealth of case studies documenting the hydrologic functions of individual catchments. Numerous comparison metrics have been proposed based on some ratio of fluxes. Fluxes, however, are just one side of the water balance equation. It is essential to understand how a catchment retains water as well as how it releases water. Changes in storage – the filling and releasing of soil moisture, the accumulation and decline of snow, the rise and fall of groundwater –moderate the fluxes and exert critical controls on a wide range of hydrologic and biologic functions of a catchment. It is volume of water stored within a basin and its partitioning between groundwater, soil moisture, snowpack, vegetation, and surface water that ultimately characterizes the state of the hydrologic system. Accordingly, catchment water storage dynamics may serve as insightful metrics for catchment inter- comparison. CUAHSI has initiated a Catchment Intercomparison Exercise to assess the value of using storage dynamics as an intercomparison metric. This talk summarizes some initial results from catchments in the US, Scotland, and Sweden.

Reconciling storage estimates in montane catchments: Hydrometric and tracer-based approaches in inter-catchment comparisons C. Soulsby*, D. Tetzlaff and M. Hrachowitz Northern Rivers Institute, School of Geosciences, University of Aberdeen, Aberdeen, UK

Estimating water storage is a major challenge in catchment hydrology, both in terms of empirical investigations and modelling studies. Whether attempting to quantify storage in individual system components (e.g. snowpack, soils, aquifers etc) or the whole catchment; heterogeneity, temporal dynamics and measurement uncertainty invariably result in poorly constrained estimates. In this contribution we examine the different insights gained into storage from hydrometric observations, modelling studies and the input-output relationships of natural tracers in different catchments in the Scottish Highlands. While hydrometric data and modelling results reveal largely consistent magnitude and temporal dynamic of “active” storage, damping of natural tracers strongly infers a much larger “total” storage at the catchment scale. The reasons for this discrepancy are examined. The potential for using natural tracers to estimate storage in different types of catchment will be explored and the limitations of the approach discussed.

Riparian zone control on stream dissolved organic carbon dynamics: Using storage to define the limits of DOC flushing during spring flood Kevin Bishop, Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences,

Where does runoff get its chemistry? Defining the sources, flow pathways and residence times of water in catchments has been one key to answering questions about terrestrial controls on water chemistry. The storage of water in the catchment is an additional source of information that can further constrain the origin of water chemistry. This presentation uses information about water storage along flow pathways in a boreal catchment to investigate whether the pulse of dissolved organic carbon during spring flood has been ”flushed” from the catchment. In contrast to many minerogenic constituents of runoff, DOC concentrations can increase as flow increases two orders of magnitude from winter base flow to the peak of spring flood. This single event can account for 25-50% of annual runoff and a similar proportion of annual the aquatic carbon flux. One possible mechanism for this is that the C leaving the catchment during spring flood accumulated in soil solution during a long period of low flow. Analysis of stored water that can be hydrologically connected to the stream during spring melt, however, suggests that while an initial increase of DOC can be ”flushed” from the catchment soil solution, ca 80% of the DOC in spring flood was in the solid phase when spring flood began and had to enter soil solution during the course of the event. This is one demonstration of how knowledge about storage can be used to improve the understanding of biogeochemical processes controlling water quality.

Spk -17 Abstracts – Invited Speakers

Wednesday Morning Session 8: Distributed Temperature Sensing: Lessons Learned

Distributed thermal perturbation sensing for monitoring subsurface processes Barry M. Freifeld, Lawrence Berkeley National Laboratory, Berkeley, CA

A novel thermal borehole-measurement method has being applied to enhance monitoring of subsurface heat- and mass-transport processes. The distributed thermal perturbation sensor (DTPS) consists of two elements, a linear heater that provides constant heating along the axis of the wellbore, and a distributed temperature sensor (DTS) for measuring temperatures. By creating a heat pulse and simultaneous registration of the change in temperature along a borehole, we can draw conclusions regarding the thermal properties of the formation and infer flow processes inside the reservoir. To date, the DTPS has been utilized for monitoring fluid flow, estimating formation thermal conductivity, and estimating phase saturation over a diverse range of projects spanning diverse lithologies and environments. While the experiments have varied objectives, the experimental methodology remained consistent—the boreholes are heated with a power of ~20 W/m for intervals of about two days, during which the borehole temperature increases ~4–10°C, depending on the lithology of the formation. The cooling profiles are subsequently monitored, and the collected data are interpreted using an applicable conceptual model.

At the High Lake field site in Nunuvut Territory, Canada, DTPS data were interpreted to determine basal heat flux and formation thermal conductivities in a deep permafrost environment. This information, along with the borehole thermal profile, was used to estimate the ground surface-temperature history. Similarly, a DTPS sensor was deployed at the CO2SINK CO2 sequestration demonstration project in Ketzin, Germany. Baseline DTPS data provided a thermal conductivity log for the injection well and two monitoring wells. Changes in the thermal conductivities after the start of CO2 injection were used to infer zones of CO2 flow and increases in CO2 saturation. Development of hybrid DTPS cables is an area of active research, particularly for deployment within the hostile environment of geothermal systems. Some of the latest technological advances are presented, along with upcoming deployments.

Use of distributed-temperature sensing systems by the U.S. Geological Survey John W. Lane1*, Frederick D. Day-Lewis1, Lee D. Slater2, Carole D. Johnson1, and Rory D. Henderson1 1U.S. Geological Survey, Storrs, CT 2Rutgers University, Newark, NJ

The U.S. Geological Survey (USGS) began using Fiber-Optic Distributed-Temperature Sensing Systems (DTS) in 2006, with the initiation of a national DTS demonstration and evaluation project through the Office of Groundwater. At that time, DTS applications were generally directed toward (1) assessment of groundwater/surface-water interaction through the delineation of gaining reaches and focused discharge to identify locations for hydraulic testing, geochemical sampling, and installation of vertical thermal monitoring arrays; and (2) the assessment of aquifer-estuary dynamics and hyporheic exchange. Since 2006, the use of DTS in the USGS has expanded to include ecological assessments of rivers and streams (e.g., the thermal effects of urban runoff and power production on aquatic health); borehole monitoring of aquifer storage and recovery (ASR); and aquifer monitoring in volcanically active areas. Integration of DTS with other geophysical exploration methods [such as land or waterborne electrical resistivity imaging (ERI) and induced polarization (IP)] has proven an extremely useful strategy for hydrogeophysical characterization and monitoring. Whereas the ERI and IP methods provide information on aquifer structure, grain-size distribution, pore-fluid chemistry, and lithologic indicators such as the presence of clays, DTS permits the delineation of hydraulically active zones and thermal changes in response to hydraulic forcings such as recharge events or changes in stage.

Interest and application of DTS methods within the USGS is increasing rapidly, with some barriers to entry beginning to dissipate while others emerge. DTS instruments are changing: capabilities are improving while costs are decreasing. As the cost of DTS systems and instrument power requirements both fall, the potential applications for routine (and remote) DTS deployments expand, as does the possibility for DTS to contribute to the long-term record. However, the pace of innovation also presents an internal training burden, and as use of DTS spreads beyond a core group of skilled users, codes written for specific platforms (e.g., Matlab) are not always useful. New techniques (e.g., time-frequency analysis)

Spk -18 Abstracts – Invited Speakers

are needed to mine and interpret large DTS datasets. Finally, the lack of an industry-wide standardized data file format presents a data archiving challenge and a further barrier to entry to those new to the field or those interested in analysis of data collected from different instruments. Adoption of a common data format (similar to the SEG-Y standard for seismic data) would facilitate growth in the use of DTS methods, aid the development of common analysis software, and ensure that data collected today will be useful to future generations of earth scientists.

Field deployment guidelines for distributed temperature sensing (DTS) systems Michael Mondanos, Sensornet Ltd.

Distributed Temperature Sensing (DTS) is a technology used to monitor the temperature distribution along an optical fiber. The technology based on the principle of Optical Time Domain Reflectometry (OTDR) uses the spectral lines of inelastic scattering interactions in standard communication optical fibers to quantify for localized thermal effects. The technology although mainly driven by applications in the oil and gas exploration is proven to be a powerful tool for many branches of geology and geophysics for hydrological processes and ecological monitoring.

The application and measurement requirements determine the type of instrument to be used. Parameters to be considered such as the distance, dynamic range, spatial, temporal and temperature resolution are usually associated with the characteristics of the system. Others such as accuracy and error performance although related to the specifications of the instrument are dependent to the DTS configuration and calibration of the installation. User or instrument defined reference points are required to calibrate against temperature slope and offset variations often related to external induced attenuations on the optical fiber cable. In addition the environment temperature dependence of the optoelectronic demodulator needs to be considered.

System defined configuration options such as Dynamic Temperature & Slope Correction, Double Ended and Matched Sections are calibration utilities designed to overcome step attenuations and differential attenuation along the optical fiber. It is recommended that all installations should include a minimum of two fibers in the cable to allow for Double Ended or U-Turn deployment. It is also recommended prior to any measurements to optimize the fiber cable installation ensuring attenuations are kept to a minimum.

Spk -19 Abstracts – Invited Speakers

Name Index to Speaker Abstracts

Bishop ...... Spk-17 Maxwell ...... Spk-1 Famiglietti ...... Spk-1 McGuire ...... Spk-13 Freifeld ...... Spk-18 McNamara ...... Spk-17 Genereux ...... Spk-7 Minsker ...... Spk-12 Haggerty ...... Spk-6 Mondanos ...... Spk-19 Harman ...... Spk-13 Ng...... Spk-10 Harvey ...... Spk-2 Packman ...... Spk-3 Hirschboeck ...... Spk-15 Parlange ...... Spk-1 Jencso ...... Spk-13 Salvucci ...... Spk-4 Kirchner ...... Spk-2 Smerdon ...... Spk-9 Krajewski ...... Spk-15 Smith ...... Spk-16 Krause ...... Spk-6 Soulsby ...... Spk-17 Kustas ...... Spk-4 Troch ...... Spk-5 Lane ...... Spk-18 VanBriesen ...... Spk-11 Loheide ...... Spk-10 Weiskel ...... Spk-11

Poster Abstracts

Poster Abstracts Title Index to Poster Abstracts

Poster Abstract Title Abstracts Tab Location page number

1. Nolin — Modeling watershed-scale distributions of snow for present-day and future climate in the Pacific Northwest, United States ...... 1 2. Mahat — Modeling the effect of vegetation on the accumulation and melting of snow ...... 1 3. Raleigh — A snow hydrologist’s time machine: determining winter snow accumulation with springtime mass and energy exchanges at the air-snow interface ...... 2 4. Lo — The role of groundwater in AGCM precipitation simulations ...... 2 5. Lundquist — Relationships between barrier jet heights, precipitation distributions, and streamflow in the Northern Sierra Nevada ...... 3 6. Hwang, Syewoon — Spatial variance correction technique for downscaled climate modeling results ...... 3 7. Kumar — Evaluation of NARR and CLM3.5 outputs for surface water and energy budgets in the Mississippi River Basin ...... 4 8. Hsu, Chengmin — Downscaling of AMSR-E soil moisture using thermal sensors and a physically- based model ...... 4 9. Flores — Data assimilation can improve hydrological applications at hillslope scales: an example using synthetic SMAP observations ...... 5 10. Gleeson — Compiling regional-scale permeability estimates for a global map of near-surface permeability ...... 6 11. de Linage — Extraction of the surface water contribution from GRACE total water storage anomalies in the Amazon Basin and contribution to the study of the kinematics of surface waters ...... 6 12. Reager — Application of a frequency-domain terrestrial water balance using GRACE ...... 6 13. Voss — A global groundwater stress index from estimates of groundwater withdrawal and recharge ...... 7 14. Williams — Quantifying and reducing hydrogeologic uncertainty in a fully-coupled land-atmosphere model ...... 7 15. Ferguson — Groundwater—land surface—atmosphere feedbacks: Impacts of groundwater pumping and irrigation on land-atmosphere interactions ...... 7 16. Kustu — Large-scale water cycle perturbation due to irrigation pumping in the US High Plains: Observational evidence of increased summer streamflow downwind ...... 8 17. Biggs — Vulnerability of irrigated agriculture to water supply shocks in river basins: The spatial structure of agricultural response to drought in India ...... 8 18. Choi — Expanding the role of drought in the hydrologic cycle ...... 9 19. Weider — The relationship between water table response and climatic variables in the New England region over the last 60 years ...... 9 20. Al-Gamal — An assessment of recharge possibility to North-Western Sahara Aquifer System (NWSAS) using environmental isotopes ...... 10 21. Chen — Determination of stream-aquifer hydrological connectedness in the Platte River, Nebraska ...... 10 22. McEnery —Flux of a conserved contaminant between stream beds of varying composition and overlying stream flow ...... 11 23. Fryar — Groundwater discharge and contaminant fluxes along a channelized coastal plain stream ...... 11 24. Cowie — Use of isotopic and geochemical tracers to identify source waters and subsurface residence times within headwater catchments in Boulder Creek Watershed, Colorado ...... 12 25. Zarnetske — Labile dissolved organic carbon supply limits hyporheic denitrification ...... 12 26. Ivanov — A study of water uptake by a mature Amazonian rainforest ...... 13 27. Voepel — Hydrologic controls on catchment-scale vegetation productivity ...... 13 28. Hwang, Taehee — Hydrologic gradients of vegetation density as an indicator for lateral connectivity of headwater catchments ...... 14 Poster Abstracts Title Index to Poster Abstracts

Poster Abstract Title Abstracts Tab Location page number

29. Duncan — Quantifying landscape controls on riparian biogeochemical hotspots in a Piedmont forested catchment ...... 14 30. Tetzlaff — Hydrological resistance, resilience and hydro-climatic controls on dissolved organic carbon fluxes in northern catchments: Insights from the North-Watch intercomparison ...... 15 31. Hawthorne — Stream directed airflow and anabatic/katabatic dynamics at a headwater stream in a Pacific North-Western Douglas-fir forest ...... 15 32. Johnson — Carbon drainage pathways in a Douglas-fir headwater catchment in the Pacific Northwest ...... 16 33. Hinshaw — Denitrification and the production of nitrous oxide in subtropical riparian zones ...... 17 34. Basu — Anthropogenic signatures in nutrient loads exported from managed catchments: Emergence of effective biogeochemical stationarity ...... 17 35. Ward — Hydrostatic pumping as a mass transport mechanism during storm events and diel flow cycles ...... 18 36. Ward — How do hyporheic flowpaths change as a result of in-channel restoration structure installation? ...... 18

37. Siirila — A quantitative methodology to assess the risks to human health from CO2 leakage into groundwater ...... 18 38. Sun — SWMM-based green infrastructure enhanced storm water modeling ...... 19 39. Lindner — Hydraulic modeling of discharge rating curves in urban streams ...... 19 40. Bhaskar — Water balances in urbanized metropolitan Baltimore ...... 20 41. Seck — Implementation of an integrated distributed model of the Chesapeake Bay Watershed using ParFlow ...... 20 42. Starzyk — Integrating a surface water-groundwater model with robust estimates of baseflow: Bertrand Creek Watershed, BC ...... 21 43. Atchley — Influences of subsurface heterogeneity and vegetation cover on soil moisture, surface temperature, and evapotranspiration at hillslope scales ...... 21 44. Meyerhoff — Quantifying the effects of subsurface heterogeneity on hillslope runoff using a stochastic approach ...... 22 45. Srivastava — An integrated approach to investigate the hydrological behavior of the Santa Fe River Basin, north central Florida ...... 22 46. Martinez — Implementing complexity criteria into diagnostic evaluation methods for water balance models (in a large national dataset) ...... 23 47. Tan — A methodology for evaluating alternative long-term monitoring networks for water quality in large watersheds with uncertain weather ...... 23 48. Woodbury — Modeling variable source area hydrology on flow and phosphorus transport predicted by a SWAT model for the Cannonsville Watershed ...... 24 49. Newman — Hydrologic function in large floodplains ...... 24 50. Schneider — The Hydrometeorology Testbed (HMT): Developing new tools to address water resources challenges in a changing climate ...... 24 51. Shaw — Assessing possible changes in flood frequency due to climate change in mid-sized watersheds in New York State, USA ...... 25 52. Briggs — A comparison of distributed temperature sensing to traditional methods of evaluating groundwater influx to streams ...... 25 53. Hatch — Using distributed temperature sensing (DTS) as tool for identifying thermal refugia in headwater streams ...... 26 54. Williamson — Assessing spatial variability of soil thermal properties using distributed temperature sensing ...... 27 Poster Abstracts Title Index to Poster Abstracts

Poster Abstract Title Abstracts Tab Location page number

55. Suárez — Monitoring the temperature profile in a solar pond using a vertical high-resolution distributed-temperature-sensing system ...... 27 56. Hausner — Evidence of seasonal convective mixing in Devils Hole, Death Valley National Park, Nevada ...... 28 57. Hsu, Kevin (Wei-Te) — Client-side Web services for water resources management: Russian River case study ...... 28 58. Woldt — The WATER Machine: A large format water education system for insights into water across interfaces ...... 29

Poster Abstracts

1 Modeling watershed-scale distributions of snow for present-day and future climate in the Pacific Northwest, United States

Anne Nolin* and Eric Sproles, Department of Geosciences, Oregon State University, Corvallis, OR

The snowmelt-dominated Cascade Mountains provide critical water supply for agriculture, hydropower, ecosystems, and municipalities throughout the Pacific Northwest. Empirical analyses and models of projected climate change show rising temperatures in the region. This temperature trend is accompanied by a shift from snowfall to rainfall at lower elevations and earlier snowmelt. In this study we model the spatial distribution of Snow Water Equivalent (SWE) in the McKenzie River Basin, Oregon (3000 km2). We use the physically based SnowModel with a grid resolution of 100 m and a daily time step. Model inputs include meteorological data, a digital elevation model, and land cover information. We compute the ratio of SWE to total winter precipitation (SWE/PRE) for the period of 2000-2009. The model is evaluated using point-based measurements of SWE, precipitation, and temperature and spatially, using snow cover extent from the MODIS instrument. SnowModel simulations are in very good agreement with measured SWE for most stations with Nash-Sutcliffe model efficiency values exceeding 0.9 in most cases. Agreement with MODIS snow cover data show a total difference of 7.1% at the time of peak SWE with the largest difference in valley bottoms (where vegetation is dense and snow cover is difficult to view with the satellite data).

For the future climate scenarios, meteorological inputs are perturbed based upon downscaled Intergovernmental Panel on Climate Change model predictions. The temperature and precipitation forcing data for 2000-2009 were perturbed to represent projected climate changes based on a composite of nineteen IPCC climate models (scenario A1B) downscaled to the Pacific Northwest region for the period 2030-2050. These perturbations were computed using the change from present-day climate to a projected future climate (delta value). The delta value was applied to daily temperature and precipitation data using a prescribed monthly value and the model was rerun using these perturbed values. Our perturbed simulations show substantial losses in SWE throughout the watershed. However, interannual variability under projected climate change can generate increases in SWE at high elevations but overall declines in basin-wide SWE. Thus, while there is a significant loss of snow covered area and volumetric water storage in the form of snow, the spatial changes in SWE are highly heterogeneous. This has important implications for runoff predictions as well as for design and implementation of snow monitoring networks.

2 Modeling the effect of vegetation on the accumulation and melting of snow Vinod Mahat and David G. Tarboton, Department of Civil and Environmental Engineering, Utah State University, Logan, UT

To model the effects of canopy on snow processes new parameterizations of snow interception, unloading and melt from the canopy; radiation transfer through the canopy; and heat and vapor transfer processes between snow on the ground, in the canopy and the atmosphere above were developed for a physically based energy balance snowmelt model. The enhanced model was driven by the weather data comprised of hourly measurements of precipitation, temperature, wind speed and relative humidity from open (grass/shrub) area. These measurements were taken to represent weather condition above the canopy. The model then simulated snow processes in the open (grass/shrub) as well as in and beneath different forest canopies (evergreen/deciduous). We report the comparison of model simulation of meteorological conditions (temperature, wind, radiation) and snow properties (water equivalent, depth, temperature) with observations made in the open, evergreen and deciduous forest at the TW Daniel Experimental forest (TWDEF) located 30 miles N-E of Logan. Observations showed approximately 10- 20% more snow accumulation in open area than in forested area. Ablation rates were also found to be higher in open area than in forested area. In comparison to evergreen forest, deciduous forest had higher rates of accumulation and ablation. The model performed well in representing these effects based on inputs such as canopy height, canopy coverage and leaf area index; thereby improving our ability to simulate and predict snow processes across heterogeneous watersheds.

Pst-1 Poster Abstracts

3 A snow hydrologist’s time machine: determining winter snow accumulation with springtime mass and energy exchanges at the air-snow interface Mark S. Raleigh* and Jessica D. Lundquist, Department of Civil and Environmental Engineering, University of Washington

In the maritime mountains of Washington, Oregon, and California, snowfall is a major component of the hydrologic cycle, comprising 50-67% of annual precipitation. In this region, 85-95% of annual precipitation falls between October and May, making snowmelt a critical resource during the dry summer months. Because of gauge scarcity and heterogeneous precipitation distributions in this region, it is difficult to know how much snow accumulated across a basin by the end of winter. While water supply forecasters avoid this uncertainty by using regression models with weather station and stream gauge data, these regression models cannot reliably estimate snow accumulation at unmonitored sites within the basin. Knowledge of snow distributions across a basin is important because seasonal snowpack has critical interactions with mountain ecology. Additionally, snowfall distributions are required to drive distributed hydrologic models. Thus, there is a need for a reliable method to estimate unmonitored snow patterns.

Spatial distributions of winter snow accumulation can be derived from the mass and energy exchanges at the air-snow interface during the spring melt season. To “hindcast” peak accumulation of snow water equivalent (SWE) at the end of winter, total spring season snowmelt is summed and any new snowfall is subtracted. These exchanges are calculated prior to the observed snowpack disappearance date, which can be acquired from different sources, such as remote sensing instruments or ground temperature sensors. This method of hindcasting peak SWE, known as “SWE reconstruction,” has been employed in other studies, but none of these have provided comparisons against directly observed SWE at more than five snow courses or snow pillows. Several of these studies also excluded spring snowfall in the reconstruction mass balance; the validity of this assumption ultimately depends on regional climate and spring weather conditions during each water year.

Here we evaluate the SWE reconstruction approach at over 130 snow pillows in the maritime ranges to compare reconstructed SWE against “ground truth.” Annual snow disappearance dates were obtained directly from daily snow pillow observations. The operational Snow-17 model was selected for this study because it requires minimal input data to estimate snowmelt. Here we demonstrate why snowfall cannot be excluded when reconstructing SWE in maritime mountain ranges. To include spring snowfall in the reconstruction mass balance, we scaled precipitation from the nearest gauge, such that scaled annual snowfall equaled estimated annual snowmelt. This addition reduced the median error by 13% when reconstructing peak SWE. We also reveal the errors introduced in the Snow-17 reconstruction when snow disappearance date is misdiagnosed; this is an important parameter because the ability of remote sensing instruments to observe snow disappearance is limited in forested and complex terrain. This study provides error bounds and guidance when applying the SWE reconstruction method with Snow-17 in maritime mountain ranges.

4 The role of groundwater in AGCM precipitation simulations Min-Hui Lo and James S. Famiglietti, Department of Earth System Science and UC Center for Hydrologic Modeling, University of California, Irvine

The representation of groundwater dynamics in land surface models (LSMs) has received considerable attention in recent years. Most studies have found that soil moisture increases after adding a groundwater component in LSMs due to the additional supply of subsurface water. However, the impact of groundwater on the spatial-temporal variability of precipitation has received little attention. Land water storage has a memory much longer than atmospheric precipitation. This characteristic of land persistence can enhance extreme climatic events, e.g., floods and droughts. Previous studies have shown that most general circulation models (GCMs) simulations underestimate the variance and long term persistence of observed precipitation. Hence, we propose the hypothesis that groundwater representation in LSMs can enhance precipitation persistence in GCMs simulations. In this study, we will use a fully coupled model, the NCAR Community Atmosphere Model + Community Land Model + groundwater aquifer, with Pst-2 Poster Abstracts prescribed sea surface temperature to study impacts of groundwater on the atmosphere. Preliminary results indicate that groundwater can increase precipitation persistence for some regions due to an increase of the soil moisture persistence.

5 Relationships between barrier jet heights, precipitation distributions, and streamflow in the Northern Sierra Nevada Jessica D. Lundquist1*, Justin Minder2, Paul J. Neiman3, Ellen Sukovich3,4

1 Civil and Environmental Engineering, University of Washington, Seattle, Washington 2 Atmospheric Science, University of Washington, Seattle, Washington 3 NOAA Earth System Research Laboratory, Physical Sciences Division, Boulder, Colorado 4 University of Colorado, CIRES, Boulder, Colorado

The rate of precipitation increase with elevation, termed the orographic precipitation gradient (OPG), is critically important for hydrologic forecasting in mountain basins that receive both rain and snow. Here we examine how well the following are able to predict the OPG and how it changes between storms and years : (1) a linear model of orographic precipitation forced by upstream radiosonde data, (2) monthly PRISM precipitation data, and (3) seven years of hourly wind profiler data used to identify characteristics of the Sierra barrier jet (BJ), discussed in P. Neiman’s preceding talk. These are compared against 124 daily-resolution (four of which also had quality-controlled, hourly resolution) precipitation gage records in the northern Sierra Nevada. All methods represent the OPG well in the mean and during a year when less than 30% of the precipitation occurred on days with BJs. However, the linear model and PRISM do not adequately capture annual variations in the OPG during years when more than 70% of the precipitation occurred on days with BJs. Throughout all years, wind profiler data indicating the height of the BJ provided additional, and necessary, information. The OPG is inversely proportional to the height of the BJ. The BJ height is lower, and hence, the OPG greater, when the westerly winds are stronger, with more vertical wind shear. These westerly storms result in greater increases of precipitation with elevation, which act to increase snow storage in most storms but also to increase storm runoff during warmer-than-average storms.

6 Spatial variance correction technique for downscaled climate modeling results Syewoon Hwang, Wendy Graham, Alison Adams, Chris Martinez, and James W. Jones, University of Florida

Accurately representing the spatial variability of precipitation is an important factor for predicting watershed response to climatic forcing, particularly in small, low-relief watersheds affected by convective storm systems. Although Global Circulation Models (GCMs) generally preserve spatial relationships between large-scale and local-scale mean precipitation trends, most GCM downscaling techniques focus on preserving only observed temporal variability on point by point basis, not spatial patterns of events. Downscaled GCM results (e.g., CMIP3 ensembles) have been widely used to predict hydrologic implications of climate variability and climate change in large snow-dominated river basins in the western United States (Diffenbaugh et al., 2008; Adam et al., 2009). However fewer applications to smaller rain- driven river basins in the southeastern US (where preserving spatial variability of rainfall patterns may be more important) have been reported.

In this study a method was developed to bias-correct GCMs to preserve both the long term temporal mean and variance of the precipitation data, and the spatial mean and variance of daily precipitation fields. Forty-year retrospective simulations (1960-1999) from 16 GCMs were collected (IPCC, 2007; WCRP CMIP3 multi-model database: https://esg.llnl.gov:8443/), and the daily precipitation data at coarse resolution (i.e., 280km) were interpolated to 12km spatial resolution and bias corrected using gridded observations over the state of Florida (Maurer et al., 2002; Wood et al, 2002; Wood et al, 2004). A new statistical spatial correction technique, developed to preserve the spatial variability of observed daily climatology, was then applied to the temporally bias-corrected results. The spatial variability and seasonal and inter-annual variability of the spatially and temporally corrected precipitation fields were evaluated against gridded observations, and compared to the original temporally bias-corrected CMIP3 data for Pst-3 Poster Abstracts

Florida. In the next phase of this research the hydrologic response of two southwest Florida watersheds to the gridded observation data, the original bias corrected CMIP3 data, and the new spatially and temporally corrected CMIP3 data will be compared using an integrated surface-subsurface hydrologic model developed by Tampa Bay Water.

7 Evaluation of NARR and CLM3.5 outputs for surface water and energy budgets in the Mississippi River Basin Sanjiv Kumar* and Venkatesh Merwade, School of Civil Engineering, Purdue University

Reanalysis outputs are often used for verification of global climate model outputs. The reanalysis outputs are also useful for studying the surface water and energy budgets at the basin scale, which is important for understanding of hydrologic cycle. However, reanalysis outputs can have biases and uncertainties, which need be analyzed and quantified to improve our confidence in these data. The objective of this study is present a comparative analysis of high resolution reanalysis outputs, coarse resolution global climate model outputs, and observation data.

The North American Regional Reanalysis (NARR) and Community Land Model (CLM 3.5) outputs have been analyzed to characterize the surface water and energy budgets in the Mississippi River Basin (MRB). The NARR and CLM3.5 outputs have been evaluated with energy flux observations from 16 AmeriFlux sites (average data length: 6 years) in the MRB. The issue of point scale observations vs. climate model grid cell outputs has been addressed with long term monthly precipitation and temperature observations from 71 USHCN (United Sates Historical Climatology Network) stations in Indiana and Illinois. The model outputs also have been evaluated to capture observed spatial and temporal variability in the total runoff.

The results show that NARR outputs have significant biases in incoming solar radiations (26%), latent heat flux (41%), and sensible heat flux (26%). Compared to NARR, the CLM3.5 outputs show smaller biases in incoming solar radiation (0.5%) and latent heat flux (11%). However, the CLM 3.5 outputs overestimate sensible heat flux during the summer in the humid region of the MRB. The NARR outputs capture the observed bimodal pattern of sensible heat flux in the crop region; whereas CLM 3.5 outputs do not show the bimodal pattern. For long term average (1980-2004), NARR outputs show large water balance closing error (Runoff + Evapotraspiration = 1.44 * Precipitation), and also small energy balance closing error (latent + sensible + ground heat flux = 1.1 net radiations) for the MRB. The energy and water balance closing error was not found in the CLM3.5 outputs. The monthly variations and magnitude of total runoff is also well captured by the CLM3.5 outputs.

8 Downscaling of AMSR-E soil moisture using thermal sensors and a physically-based model Chengmin Hsu1, Robert Zamora2, Lynn E. Johnson3, Tim Schneider2

1 Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder 2 NOAA Earth System Research Laboratory 3 Department of Civil Engineering, University of Colorado Denver

Soil moisture is a critical variable in a wide variety of applications. But the data is scarce; only in-situ point data can be found, and only in a small area. Currently, there are only two sources of operational global soil moisture data from satellites. One is the data generated from the observations of the Advanced Microwave Scanning Radiometer (AMSR-E) aboard NASA's Aqua satellite. The other is the data produced from the recently launched Soil Moisture and Ocean Salinity (SMOS) satellite by European Space Agency. However, neither is a high resolution product. The AMSR-E surface soil moisture product has a 25-km resolution, whereas SMOS can create only 50-km resolution products. In practice, soil moisture at such a coarse resolution has only limited value. A deterministic approach for downscaling 25 km resolution AMSR-E daily soil moisture data is developed from the 1 km resolution Moderate Resolution Imaging Spectro-radiometer (MODIS) data and 90-m resolution Advanced Scanning Thermal Emission and Reflection Radiometer (ASTER) data. The downscaling relationship is built on creating an association between soil evaporative efficiency and near Pst-4 Poster Abstracts surface soil moisture through a physically-based scaling function. This function is created by bringing together soil property, Von Karman wind turbulence model, and aerodynamic resistance to form a semi- empirical parameter. For the soil property, we use percent clay and bulk density extracted from Soil Survey Geographic (SSURGO) database to infer published lab findings for application. Aerodynamic resistance is calculated from wind speed measurements at wind gage height given soil roughness. We use vegetation index and surface temperature data derived from MODIS and ASTER to estimate soil temperature and, subsequently, to calculate soil evaporative efficiency. In this process, MODIS is used to downscale low resolution microwave derived soil moisture to the 1-km resolution and ASTER is then used to downscale from the 1-km resolution to the 250-m resolution. To account for the lower soil moisture sensitivity of the MODIS surface temperature and the poor capability of AMSR-E to differentiate soil and vegetation signals, saturated hydraulic conductivity (Ks) extracted from SSURGO is used to explore its association with soil moisture dynamics in the drying phase. The research site encompasses the Babocomari River watershed and Walnut Gulch River watershed in Arizona. The soil moisture data from the NOAA HMT soil moisture network and streamflow data from USGS will be used for validation. The overall root mean square error between downscaled and observed soil moisture will be calculated. The robustness of the downscaling algorithms along with possible improvements to the entire process will be discussed.

9 Data assimilation can improve hydrological applications at hillslope scales: an example using synthetic SMAP observations Alejandro Flores, Boise State University

Soil water content is a critical data input for many hydrologic applications because it controls the fluxes of moisture, energy, and carbon between the land surface and atmosphere. In complex terrain, applications such as evaluation of landslide susceptibility, military trafficability assessment, and live fuel moisture estimation for wildland fires are inherently tied to spatial scales of individual hillslopes (e.g., 10s to 100s of m). Spatially distributed, physically based hydrologic models are important tools to predict the spatial distribution of soil moisture at spatial scales consistent with these applications. These models serve to integrate multiple-scale data sources that characterize the hydrometeorological forcings, as well as topographic, soil, and vegetation boundary conditions of the landscape. Owing to uncertainty in these data and the model parameters and forcings derived from them, there exists corresponding uncertainty in the simulated distributions of soil moisture. NASA’s Soil Moisture Active-Passive (SMAP) mission will provide global L-band microwave observation of the land surface approximately every 2-3 days. However, the anticipated spatial resolution of active (i.e., radar) SMAP products will be 1-3 km; coarser than the hillslope scales desirable for many applications. Data assimilation, the mathematical fusion of models and observations, provides an estimation framework through which uncertain estimates of soil moisture simulated at hillslope scales can be constrained to 1-3 km scale SMAP radar observations. In this study, we present the results of several synthetic experiments to demonstrate the potential utility of data assimilation for fusing remote sensing data with uncertain simulated soil moisture fields. In particular, we use the Ensemble Kalman Filter (EnKF) to update an ensemble of hillslope-scale soil moisture fields simulated by a physically based ecohydrology model with synthetic SMAP radar observations. For bare soil conditions, assimilation of the synthetic observations substantially reduces estimation error in near surface soil moisture (e.g., top 5 cm), relative to the synthetic true soil moisture conditions. Key components of our EnKF-based data assimilation system are: (1) an observing system that explicitly represents the impact of hillslope-scale topographic variability on local incidence angles and polarization rotation, and (2) a Latin Hypercube-based soil parameter generator that preserves correlation between soil properties and improves the reproducibility of soil moisture ensemble statistics. We demonstrate how hillslope-scale soil moisture data assimilation products could be used as input to a simple military trafficability decision support system, and discuss ongoing work to fuse multiple data sources to improve entire-profile soil moisture estimation in sparsely vegetated, semiarid watersheds of the Western US.

Pst-5 Poster Abstracts

10 Compiling regional-scale permeability estimates for a global map of near-surface permeability Tom Gleeson1*, Leslie Smith1, Nils Jansen2, Jens Hartmann2, Hans Dürr3, Andrew H. Manning4, and Rens van Beek3

1 Department of Earth and Ocean Sciences, University of British Columbia 2 Institute for Biogeochemistry and Marine Chemistry, University of Hamburg 3 Department of Physical Geography, Utrecht University, Netherlands 4 U.S. Geological Survey

Permeability is a key parameter necessary for understanding and quantitatively predicting the water flux across the land surface, the water table and the groundwater-surface water interface. Local-scale (<1 m to 1 km) permeability varies over more than 13 orders of magnitude and is often poorly defined because it is extremely heterogeneous and dependent on flow direction. The permeability of shallow soil has been mapped at continental scales. However, the regional-scale (>5 km) permeability of consolidated and unconsolidated geologic units (hydrolithologies) underlying soil is poorly understood and has not been previously mapped. Here we show that hydrolithologies have representative, regional-scale permeabilities that can be used to map the global distribution of near surface permeability. By compiling existing hydrogeological models we show that regional-scale permeability is not scale-dependent and the distribution for each hydrolithology is generally log normal with a standard deviation of 1-2 orders of magnitude. We also calculate a spatially-distributed, near-surface global mean of the logarithmic permeability of -13.2 ± 2.7 m2. Our results resolve the near-surface permeability field, at new scales and at new depths. We anticipate the permeability compilation and maps will be invaluable resources for understanding and modeling diverse earth processes.

11 Extraction of the surface water contribution from GRACE total water storage anomalies in the Amazon Basin and contribution to the study of the kinematics of surface waters C. de Linage*, M. Lo and J. Famiglietti, UC Center for Hydrologic Modeling, Earth System Science Department, University of California, Irvine.

The surface water component is a major contributor to total water storage in the Amazon basin. The GRACE mission provides monthly maps of Total Water Storage Anomalies corresponding to the vertical integration of water stored in the ground (soil moisture and groundwater), river channels and floodplains (surface waters). Using the CLM3.5 model estimates of the variations of the soil moisture and groundwater components, we isolate the surface water contribution in the GRACE observations and analyze its spatio-temporal variations within the basin. Our results are then compared to an independent estimate using a combination of remotely-sensed observations (altimetry and multi-satellite inundation extent data). Finally, we use the GRACE surface water residues in order to calibrate the river flow velocity in the CLM river routing model. The calibrated velocity of 0.15 m/s is smaller than the default velocity of 0.35 m/s used in CLM.

12 Application of a frequency-domain terrestrial water balance using GRACE JT Reager* and JS Famiglietti, UC Irvine

GRACE terrestrial water storage and GPCP precipitation data are used to analyze the frequency response of storage to fluctuations in forcing, globally. Assuming that a river basin functions as a linear system and that terrestrial water balance variables are mutual coherent, we take the traditional approach of multi-input systems cross-spectral analysis to calculate the relative contribution of precipitation input to observed storage output. For this application, basin-averaged precipitation will be multiplied by a complex transfer function that defines the frequency range and amplitude of the input term’s contribution. To better understand the regional dependence of rainfall-storage partitioning, the transfer functions are then scaled across different large basins, utilizing various scaling parameters. This functional relationship will present an observation-based definition of precipitation partitioning into storage across multiple basin sizes and types.

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13 A global groundwater stress index from estimates of groundwater withdrawal and recharge K. Voss1,2*, J. Famiglietti2,3, M. Lo2,3, C. de Linage2,3, J. Reager2,3, M. Rodell4

1 School of Foreign Service, Georgetown University 2 UC Center for Hydrologic Modeling, University of California, Irvine 3 Department of Earth System Science, University of California, Irvine 4 Hydrological Sciences Branch, Code 614.3, NASA Goddard Space Flight Center

Over 2 billion people rely on groundwater as their primary source of fresh water for consumptive and agricultural use, yet most research on characterizing water stress indices has not included groundwater aquifers. This study explicitly evaluates groundwater use compared to groundwater recharge to create a global groundwater scarcity index in order to determine which regions of the world face groundwater stress. Per capita groundwater use data were compiled by country. These were combined with higher- resolution global population maps to determine global patterns of groundwater use. Groundwater recharge was estimated by taking the long-term average from the output of a global hydrological model. A groundwater stress index was created by dividing rates of groundwater withdrawal by rates of groundwater recharge and applying a standard scarcity scale established by the United Nations. The resulting map correctly reflects known regions of water stress. The global map of the groundwater stress index was compared to trends in net groundwater recharge derived from a combination of GRACE data and hydrological model output. The comparison highlights important differences between the long-term average approach based on by-country reporting, and direct observation of the recent past from satellite data. Furthermore, it underscores the need for an accelerated effort to collect and compile accurate global groundwater datasets.

14 Quantifying and reducing hydrogeologic uncertainty in a fully-coupled land-atmosphere model John L. Williams, III* and Reed M. Maxwell, Department of Geology and Geological Engineering, Colorado School of Mines,

Using ParFlow-WRF, a fully-coupled land-atmosphere model incorporating a variably saturated subsurface flow model, we evaluate responses in land-atmosphere feedbacks to heterogeneity in subsurface properties. To accomplish this, we first generate an idealized domain with heterogeneous, subsurface properties using correlated, Gaussian random fields. We then induce heavy rainfall using a moisture tendency over a straight line in the center of a fifteen by fifteen kilometer model grid within the atmospheric portion of the fully-coupled PF.WRF model grid domain to create changes in subsurface moisture and overland flow. We complete ensembles of model runs, each with different random seeds, and monitor the of surface runoff, saturation, and land-atmosphere feedbacks at and near the ground surface. Finally, using conditional Monte Carlo simulations, we also incorporate subsurface data to evaluate the reduction of uncertainty in soil moisture and subsequent impacts on land-atmosphere feedbacks.

15 Groundwater—land surface—atmosphere feedbacks: Impacts of groundwater pumping and irrigation on land-atmosphere interactions Ian M. Ferguson* and Reed M. Maxwell, Department of Geology and Geological Engineering, Colorado School of Mines

Recent studies have shown that interactions between groundwater, surface water, and land surface processes significantly influence the land surface water and energy balance. These studies suggest that water management practices which alter the distribution of water between the subsurface and near- surface—viz., groundwater pumping and irrigation—will impact terrestrial water and energy budgets at local and watershed sales, with potentially significant feedbacks across the hydrologic cycle. Here we use an integrated hydrology model to evaluate impacts of physically-realistic groundwater pumping, irrigation, and combined pumping and irrigation on groundwater storage, land surface fluxes, and stream discharge over a study area in the Southern Great Plains of North America. Both pumping and irrigation are shown to impact water and energy fluxes at local and watershed scales, with the magnitude of impacts governed Pst-7 Poster Abstracts by local water table depth. When pumping and irrigation are combined, irrigation is shown to have a dominant impact on spatially distributed surface energy processes while pumping has a dominant impact on basin-integrated hydrologic processes. Results have important implications regarding the scale of human impacts on weather and climate.

16 Large-scale water cycle perturbation due to irrigation pumping in the US High Plains: Observational evidence of increased summer streamflow downwind Muruvvet D. Kustu and Ying Fan, Department of Earth and Planetary Sciences, Rutgers University, New Brunswick, NJ.

This study is the third part of a series of three papers. In the first part, we investigated the effect of long- term, large-scale irrigational pumping on spatial and seasonal patterns of streamflow regimes in the High Plains aquifer using extensive observational data. The trend and step changes results of streamflow, groundwater and precipitation time series covering the period of intensive irrigation development (1930- 1980) indicated a more significant depletion of streamflow in the Northern High Plains with a gradual decrease towards the Southern part, attributable to the significant declines in groundwater levels. In the second part, we analyzed precipitation records over the central U.S. searching for signals of irrigation- enhanced precipitation. The results revealed a precipitation increase of 15-30% during the peak irrigation month (July) downwind of the High Plains (in Illinois and Ohio River basins) coincident with the time of intensive irrigation development.

In this third part, we examined the observed streamflow records of 75 unregulated gauges in Illinois and Ohio River basins in search for a likely increase in streamflow associated with the enhanced July precipitation detected over the region as a result of extensive irrigation practices in the High Plains. The Pettitt test results of July time series indicated a significant change point in 1947 consistent with the timing of rapid irrigation development. The step change analyses of July and August time series from pre- irrigation (pre-1947) to post-irrigation (post-1947) periods showed significant increases especially in Illinois watersheds which are also temporally and spatially-consistent with the observed increase in irrigation-induced precipitation. The collective changes in streamflow for the individual basins are found to be field significant at the 5% level. In conclusion, this study emphasizes the spatial extent of the impacts of human alterations on the hydrological cycle at near-continental scale.

17 Vulnerability of irrigated agriculture to water supply shocks in river basins: The spatial structure of agricultural response to drought in India Trent W. Biggs and Alex Samarin, Department of Geography, San Diego State University

Agricultural production in southern India is limited by water availability. Water supply may vary widely in space, and is influenced by human activity and the physical environment. Human activities such as upstream irrigation or changes in the frequency of meteorological droughts can alter the spatial and temporal distribution of water supply shocks. The impact of river network structure and hydrology on the vulnerability of irrigated agriculture to drought was determined for several large irrigation systems located in two river basins (Krishna, Godavari) in southern India. Cropping systems were mapped for a normal water year (2001-2002) and for a drought year (2002-2003) using multi-temporal satellite imagery. Simple hypotheses were tested describing the spatial structure of the crop changes during the drought. We hypothesized that the impact of the drought would be largest in irrigation systems that 1) were located downstream of other large irrigation projects 2) were located in rivers that were hydrologically "closed" and 3) were supplied by reservoirs whose watersheds were located in dry climates. River networks structure the availability of water during water supply shocks, and future assessments of vulnerability of agriculture to climate change should use the stream network as a fundamental unit of analysis and theory.

Pst-8 Poster Abstracts

18 Expanding the role of drought in the hydrologic cycle Jennifer Jacobs1* and Minha Choi2

1Environmental Research Group, University of New Hampshire 2Hanyang University, Seoul, Korea

Long the unheralded extreme hydrologic event, remote sensing and land-surface models have brought new ways to track the spatiotemporal evolution of drought. With the ability to quantify drought condition, relationships between drought state and ecosystem stress, crop yield, and drinking water availability as well as the socioeconomic responses are rapidly emerging. Rather than relying on coarse drought indices are based on recent rainfall or changes in vegetation condition, new indicators are available that can characterize heterogeneous landscapes, soils and vegetation (type and cover) and their response to differentially stress regions even under similar weather conditions. This study examines the unprecedented recent droughts in the Southeast US caused reservoir levels to drop dangerously low, elevated wildfire hazard risks, reduced hydropower generation and caused severe economic hardships using metrics that can distinguish the heterogeneous landscapes and highly variable rainfall in the Southeastern United States. Here we present the spatiotemperal evolution of watershed scale drought using a remotely sensed stress index contrast to traditional drought indices within a water availability framework.

19 The relationship between water table response and climatic variables in the New England region over the last 60 years Kaitlyn Weider* and David Boutt, Department of Geosciences, University of Massachusetts-Amherst

The scientific evidence that humans are directly influencing the Earth’s natural climate is increasingly compelling. Numerous studies suggest that this climate change will lead to changes in the seasonality of surface water availability thereby increasing the need for groundwater development to offset those shortages. Groundwater storage and flow are constantly in flux as a response to anthropogenic and climatic stresses. This work focuses on improving and understanding how water level fluctuations in the New England region have responded to recent climatic changes and how these systems will respond to future predicted changes in Northeast climate.

Using 100 long term groundwater monitoring stations with 20 or more years of data coupled with 75 meteorological stations across the New England region, several statistical analyses are performed. Anomalies of groundwater and precipitation data are analyzed and compared regionally and within differing local aquifer systems to understand the sensitivity of the aquifer systems to change. Trend, regression and spectral analysis are performed on the groundwater data to identify statistical relationships with climatic variables, hydrogeologic properties, and the hydrologic setting.

Results suggest that regionally, New England aquifers respond strongly to yearly and decadal changes in climate. A strong coherence in the relationship between groundwater and climate variables exists with second order variability related to the hydrogeologic setting of the aquifer. The trend and regression analysis demonstrate that water level fluctuations are producing statistically significant results with increasing water levels over at least the past thirty years at most well sites. These results parallel the predicted changes in precipitation over time, with more winter precipitation falling as rain and less as snow. Groundwater appears to be de-coupled to the land-surface during times of extreme drought and exhibits strong and distinct lags compared to both precipitation and streamflow. A unique aspect of this study is that it uses existing independent groundwater, surface water, and precipitation stations as a cost effective approach to investigate long-term changes in the water table response.

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20 An assessment of recharge possibility to North-Western Sahara Aquifer System (NWSAS) using environmental isotopes Samir Anwar Al-Gamal, Department of Civil Engineering, University of Engineering & Technology, Taxila,Pakistan and Sahara and Sahel Observatory (OSS)

A comprehensive understanding is highly needed for any successful transboundary cooperation policy. Moreover, an analysis of the NWSAS can be of particular interest for policy makers and researchers. This paper aims to reveals and to assess the renewability of North Western Sahara Aquifer System(NWSAS) as one of the major transboundary multi-layered aquifer system, in North Africa, shared by Algeria, Tunisia, and Libya and is often referred to as the Système Aquifère du Sahara Septentrional (SASS).The paper is primarily intended for exploring whether it receives a considerable fraction of modern water as recharge or it is at risk of being depleted and excessively pumped, where the main challenge for NWSAS ,is that it should be abstracted rationally for equitable use.

Environmental isotopes data of δ18O, δ2H, 3H ,14C as well as characteristics of d-excess are used to illustrate whether NSWAS is renewable or non-renewable resource.Geochemical, hydrological and statistical evidences supporting the renewability of NWSAS are provided through pairs of cross-plots .

The study has clearly indicated that NWSAS is receiving a considerable fraction of modern water as recharge to the aquifer because of the following reasons; Firstly, the moderately depleted delta values of O-18 and H-2 of water from Sahara Atlas in Algeria and the Dahar and the Dj. Nefoussa in Tunisia and Libya with δ18O content (- 6.0‰ to -5.0‰) compared with that of palaeowater (-7.0 to -9.0 ‰) indicate a considerable fraction of modern water recharging NWSAS.This considerable fraction of modern water should be attributed to originate from the present-day precipitation (-6.5‰).Secondly, the presence of significant amount of 14C >2 % and 3H > 5TU., frequently found in data should be attributed to a mixing with shallow and modern water, where old water practically contains no 14C.

The foregoing facts are in good agreement with the results of conventional hydrologic approach. This would contradicts the assumption that the NWSAS is non-renewable water resource. In this context, the NWSAS is being located in one of the driest regions on the planet, these huge resources have been recognized to be of great importance to the socio-economic development of its riparian countries. So the present paper addresses the necessity of identifying specific cooperation problems which evolve out of these hydro geological attributes and prevalent use patterns.

Accordingly, the description of NWSAS as non renewable, devoid of any meaningful recharge , a rather stagnant water body, disconnected from any surface water body in addition to its classification as “non- renewable” would therefore be misleading and represents one of the most obvious inaccuracy as well.

21 Determination of stream-aquifer hydrological connectedness in the Platte River, Nebraska Xunhong Chen, School of Natural Resources, University of Nebraska-Lincoln

In the Platte River valley of Nebraska, groundwater irrigation is a key measure to enhance the agricultural production. Use of groundwater has potential impact on the streamflow because groundwater and stream water in the Platte River valley, Nebraska are recognized to have some hydrological connectedness. Integrated management of groundwater and stream water requires the knowledge of the hydrologic relation between the alluvial aquifer and the river. However, quantification of their hydrologic connection is a challenge problem. This paper presents field investigation techniques which have been used to characterize the hydrologic connectedness in a 170-km reach of the Platte River in south-central Nebraska. They include in-situ permeameter tests and direct-push methods. The direct-push method generates electrical logs for identification of the streambed layers and produces sediment cores for determination of the profiles of vertical hydraulic conductivity of the streambed. These data sets show spatial patterns of the hydrologic connectedness between the aquifer and stream along the river. These patterns are useful information in making decisions of the in surface water and groundwater management.

Pst-10 Poster Abstracts

22 Flux of a conserved contaminant between stream beds of varying composition and overlying stream flow John A. McEnery, Department of Civil Engineering, The University of Texas at Arlington,

A series of laboratory experiments in a recirculating flume were performed to investigate the flux of a conserved solute (NaCl, nominally 1 ppt) between open channel streamflow and sediment beds of varying composition. Sediments consisted of coarse (d50 = 0.71 mm) and medium (d50 = 0.33 mm) sands, and mixtures of medium sand and one to twelve percent kaolinite clay. Spatially periodic, stationary dunes along the test bed surface led to longitudinal pressure gradients that forced flow through the bed. Conductivity probes were used to measure bed salinity and compute solute flux out of the bed. Solute flux varied with the overlying flow speed, sediment permeability, and bed geometry. Peclet numbers for in-bed flow ranged from 18 to 1004. Reynolds and Froude numbers for the overlying flow ranged from 0.05 to 0.18 and 7x10-3 to 28x10-3, respectively.

Results of these laboratory measurements were examined to evaluate the significance of advective and diffusive transport mechanisms. Isohaline plots, displaying contours of equal solute concentration, clearly show periodic spatial variation in the concentration of the salt within the bed, controlled by the bedform wavelength. The total mass of solute remaining was evaluated by integrating salt concentration measurements over the vertical and horizontal limits of the bed. Graphs of the fraction of the initial mass remaining (FMR) versus elapsed time show an abrupt change in the rate of solute flux from the sediment bed early in the exchange process. As little as one percent clay caused a noticeable reduction in the rate of removal of salt from the bed. This one percent clay content appears to represent a threshold for the advective process in streambed flux. One- and two-layer, analytical models were developed based upon Fick’s law. The one-layer analytical model under estimated initial flux, and at later times over estimated flux. The two-layer solution yielded the best approximation of the experimental data. Upper layer thickness is strongly related to the sediment permeability and overlying flow speed.

23 Groundwater discharge and contaminant fluxes along a channelized coastal plain stream Alan E. Fryar*1, Danita M. LaSage, Joshua L. Sexton, and Abhijit Mukherjee

1 University of Kentucky

Groundwater discharge can contribute to the morphological evolution of streams, particularly in unlithified sediments, and to solute loads in surface water. However, the possible interplay between seepage erosion and solute fluxes has received relatively little attention. We have examined this interplay along Little Bayou Creek, an 11-km tributary to the Ohio River in the Gulf Coastal Plain of western Kentucky. Little Bayou Creek is a first-order perennial stream that was channelized along its lower 2.5 km between 1953 and 1971. Baseflow above the channelized reach is sustained by an outfall at the U.S. Department of Energy’s Paducah Gaseous Diffusion Plant (PGDP), a uranium-enrichment facility. Springs occur along the upper 300 m of the channelized reach, where the creek partly intercepts a plume of dissolved trichloroethene (TCE) and technetium-99 emanating from PGDP.

Using a combination of hydraulic measurements (gaging stream and spring flow), thermal measurements (monitoring spring temperatures and profiling temperatures in the stream bed), monitoring of solute concentrations in the stream and springs, and geologic mapping, we delineated zones of focused discharge and estimated contaminant fluxes along the channelized reach of Little Bayou Creek. Focused discharge occurs where the channel appears to intersect preferential pathways within the clayey confining unit overlying the contaminated Regional Gravel Aquifer (RGA). Seasonal variability in groundwater discharge, which tracked hydraulic-head fluctuations in an adjoining monitoring well and spring-discharge fluctuations elsewhere in the region, probably reflects seasonal variability in recharge. Contaminant concentrations in stream water fluctuated seasonally, but not always synchronously with stream flow, which suggests that discharge occurs from different parts of the RGA at different times of year. However, contaminant influxes varied seasonally with stream flow and were dominated by a few springs. Seasonal discharge fluctuations for individual springs were repressed where piping resulted in bank collapse. Focused discharge can thus contribute both to the morphological evolution of the stream channel and to Pst-11 Poster Abstracts spatio-temporal variability in contaminant influxes. Geochemical indicators (concentrations of dissolved oxygen, nitrate, and sulfate, stable Cl isotope values, and a lack of less-chlorinated ethenes) indicated that anaerobic biodegradation of TCE is unlikely. Losses of TCE along Little Bayou Creek result mainly from volatilization, in contrast to streams receiving diffuse contaminated discharge, where intrinsic bioremediation of volatile organic compounds appears to be common.

Pending work along Little Bayou Creek is intended to clarify aquifer architecture beneath springs, examine spatial variability in hydraulic properties in the vicinity of springs, and provide higher spatial- resolution data on contaminant concentrations. We plan to image thermal anomalies in summer and winter along the reach containing the springs; monitor vertical temperature distributions to quantify groundwater flow at various points; use gauging and tracer tests to infer seasonal variability in groundwater inflow; make point measurements of groundwater inflow and hydraulic conductivity (using seepage meters and a hydraulic potentiomanometer); and determine spatio-temporal variability in contaminant concentrations (using passive-diffusion and automated samplers).

24 Use of isotopic and geochemical tracers to identify source waters and subsurface residence times within headwater catchments in Boulder Creek Watershed, Colorado Rory Cowie, Department of Geography and Institute of Arctic and Alpine Research, University of Colorado

An outstanding question for snowmelt-dominated watersheds of the western US is the response of stream flow to changes in climate. We know little about mountain aquifers because they involve structurally complicated rocks, extreme head gradients, and dramatically fluctuating recharge due to seasonal snowmelt. In general, the western United States is predicted to face warmer temperatures and more frequent and prolonged droughts, and we can expect to see a decrease in annual snowpack, earlier onset of snowmelt, and increased evaporation. Understanding streamflow generation under these climatic conditions will become increasingly important as hydrologic inputs change drastically and outputs are increasingly needed for human consumption. To improve our understanding of surface/groundwater interactions, we are simultaneously collecting surface water, subsurface, and precipitation samples at four gauged headwater catchments along a 1,500-m elevational gradient: (1) Green Lakes Valley (3,500 m); (2) Como Creek (2,900 m); (3) Gordon Gulch (2,400 m); and Betasso (1,830 m). All water samples are analyzed for geochemical and isotopic (δ18O, δD) composition. The average residence time for subsurface flow is calculated by comparing the smoothing of the δ18O input (precipitation) and output (streamflow) using a convolution algorithm. The calculation of residence times is also constrained by measuring concentrations of tritium (3H), a naturally occurring radioisotope, to better understand sub- surface transit times. A two-component mixing model is used to determine source waters from old (reacted) waters and new (unreacted) waters. End member mixing analysis (EMMA) is a statistically unbiased technique that will also be used to identify the most important end members contributing to stream flow. The application of Principle Component Analysis (PCA) using the isotopic and geochemical measurements collected improves the accuracy of end member selection. Successful application of hydrograph separation and EMMA determines the proportions of sources contributing to stream flow and groundwater recharge. Additionally, the evolution of isotopic signatures (δ18O, δD) of snow will be analyzed through the transition from new precipitation to infiltration into the system during melt.

25 Labile dissolved organic carbon supply limits hyporheic denitrification Jay P. Zarnetske1, Roy Haggerty1, Steven M. Wondzell2, and Michelle A. Baker3

1Department of Geosciences & Water Resources Graduate Program, Oregon State University 2Pacific Northwest Research Station, Olympia Forestry Sciences Lab 3Department of Biology & Ecology Center, Utah State University

15 15 - We used an in situ N-labeled nitrate ( NO3 ) and acetate injection experiment to determine how the availability of labile dissolved organic carbon (DOC) as acetate influences microbial denitrification in the hyporheic zone (HZ) of an upland (3rd-order) agricultural stream. A 48 h steady-state injection of a 15 - 15 conservative tracer, chloride, and NO3 was used to quantify ambient HZ denitrification via N2 Pst-12 Poster Abstracts production. Following ambient plateau measurements of denitrification during the first 24 h, a second conservative tracer, bromide, and the labile DOC source, acetate, were co-injected for an additional 24 h to measure HZ denitrification under increased DOC supply. Conservative tracers were observed at 4 of the 6 down gradient wells. Receiving wells had HZ median residence times of 7.0 to 13.1 h, nominal -1 flowpath lengths of 0.7 to 3.7 m, and hypoxic conditions (7.5 to 9.3 mg-O2 L deficit). All 4 receiving wells 15 demonstrated N2 production during ambient conditions indicating that the HZ was an active 15 denitrification environment. The acetate addition stimulated significant increases in N2 production by - factors of 2.7 to 26.1 in all receiving wells, and significant decreases of NO3 and DOC aromaticity (via SUVA254) in the two wells most hydrologically connected to the injection. In all receiving wells, increases 15 of bromide and N2 production occurred without concurrent increases in acetate indicating that 100% of acetate was retained in the HZ, a portion of which is due to biological consumption. These results support the assertion that microbial denitrification in anaerobic portions of the hyporheic zone is limited by labile DOC supply.

26 A study of water uptake by a mature Amazonian rainforest Valeriy Ivanov, Department of Civil & Environmental Engineering, University of Michigan

Approximately half of the Amazon evergreen forests is subjected to seasonal droughts of at least three month duration. However, several flux tower studies have indicated that some rainforests may not experience a significant water stress during dry seasons. Furthermore, recent analyses of remotely sensed spectral indices point to an increased green leaf area and photosynthetic activity associated with these periods. These studies suggest both a specific phenology pattern and physiological water uptake adaptations to prolonged episodes of dry conditions. Several mechanisms have been proposed to support observations, including deep root function and hydraulic redistribution. In this study, additional possible explanatory mechanisms are investigated. A vegetation-hydrology model that parameterizes the essential water-energy processes using a simplified three-big-leaf representation of canopy vertical structure is developed. Deep soil profile explicitly resolves the propagation of wet and dry cycles into the soil column underlying forest vegetation. Observational data from the flux tower site in Tapajos National Forest are used in this study. Meteorological data for the period of 2002-2005 serve as the model forcing. Observed canopy phenology, energy fluxes, soil water dynamics, soil texture and water retention properties, and profiles of root biomass are used to parameterize and constrain the model. In a set of numerical experiments, several hypotheses are explored related to the possible effects of the characteristic phenology pattern, soil texture effects, and niche separation in root water uptake among plant types.

27 Hydrologic controls on catchment-scale vegetation productivity Hal Voepel1,2, Rina Schumer*,1, Benjamin Ruddell3, Paul Brooks4, Peter Troch4,6, Andrew Neal4, Matej Durcik4,5, and Murugesu Sivapalan7,8

1 Division of Hydrologic Sciences, Desert Research Institute, Reno, NV 2 Graduate Program of Hydrologic Sciences, University of Nevada-Reno, Reno, NV 3 Arizona State University—Polytechnic, Mesa, AZ 4 Department of Hydrology and Water Resources, University of Arizona, Tucson, AZ 5 Sustainability of semi-Arid Hydrology and Riparian Areas, University of Arizona, Tucson, AZ 6 Biosphere 2, University of Arizona, Tucson, AZ 7 Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, IL 8 Department of Geography, University of Illinois at Urbana Champaign, IL

What physical factors control regional and inter-annual variation in catchment-scale vegetation productivity? Our null hypothesis was that mean annual precipitation is the best predictor of ecosystem response at the decadal scale. To test this hypothesis we compared the power of various components of the water balance, energy balance, and landscape (catchment slope, elevation) to predict the normalized difference vegetation index (NDVI) at 320 Model Parameter Estimation Experiment (MOPEX) catchments across the United States. Statistical analysis revealed that the fraction of soil moisture transpired by plants, known as the Horton Index, described more variation (86%) in maximum annual NDVI for each Pst-13 Poster Abstracts catchment than average annual precipitation, potential evapotranspiration, or their ratio, the aridity index. The aridity index expresses the ratio of available energy to available water at the Earth surface while the Horton Index expresses a seemingly similar ratio in the subsurface. Thus, the two indices are strongly correlated. However, we found that the Horton Index is also a function of catchment slope and elevation, and is thus related to landscape characteristics that control how much and how long water is retained in a catchment. This suggests that models of vegetation productivity should emphasize plant-available soil moisture, rather than just precipitation, by incorporating both climate and landscape characteristics.

28 Hydrologic gradients of vegetation density as an indicator for lateral connectivity of headwater catchments Taehee Hwang and Lawrence E. Band, Institute for the Environment, University of North Carolina at Chapel Hill

Lateral water flow in catchments not only produces short-term variations in hydrologic and other nutrient fluxes, but also generates long-term development of ecosystem patterns. Specifically, the vegetation gradient along hydrologic flowpaths is a footprint of the redistribution of water and nitrogen by shallow subsurface flow. In this study, hydrologic gradients of vegetation density are estimated at different headwater catchments within the Coweeta LTER (Long-Term Ecological Research) site by matching observed leaf area index and normalized difference vegetation index from the summer IKONOS image information. Behavioral parameter ranges for an distributed ecohydrologic model, calculated with a GLUE (Generalized Likelihood Uncertainty Estimation) methodology, are used to characterize dominant flow regime within a set of catchments in the Coweeta LTER. Interesting correlations between hydrologic vegetation gradients, catchment runoff, and behavioral parameter ranges show the interactive role of vegetation on lateral hydrologic connectivity of catchments in addition to geomorphic controls. This study presents the potential to use the hydrologic gradients of vegetation density as a possible indicator for lateral hydrologic connectivity within the headwater catchments.

29 Quantifying landscape controls on riparian biogeochemical hotspots in a Piedmont forested catchment Jonathan M. Duncan and Lawrence E. Band, University of North Carolina at Chapel Hill. Department of Geography and Institute for the Environment

The structure of landscapes provides an important control on groundwater-surface water interactions. This same geomorphic structure interacts with vegetation to exert an important control on biogeochemical transformations and fluxes. Localized depressions and breaks in slope along downhill flowpaths serve as important areas for biogeochemical constituents. Riparian zones have long been recognized as a critical area joining hillslopes to streams but often decouple the hydrochemistry between them. This work presents preliminary results of how the geomorphic template of Pond Branch can be used to examine these controls. Pond Branch is a 41 ha forested watershed. It has been the subject of intensive study from the late 1960s to present as the reference watershed of the Baltimore Ecosystem Study LTER site. The catchment is typical of the Piedmont with broad interfluves, wide riparian zones (20-30m), and steepest slopes at midslope positions. The valley is asymmetric with the east facing slope steeper than the west facing slope, providing important implications for hydraulic gradients and flowpath depths. Drainage is less organized in the flatter upper portions of the catchment with a multi-threaded channel that transitions into a single-threaded channel and eventually into a steeper bedrock-constrained stream. A coupled ecohydrologic model with explicit flowpath routing (RHESSys) is utilized to quantify spatially distributed water, carbon, and nitrogen fluxes. Model results will be tested against distributed measurements of water table, soil moisture, and water chemistry. Later this summer, Distributed Temperature Sensing data will also be collected to assess down-valley groundwater-surface water interactions.

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30 Hydrological resistance, resilience and hydro-climatic controls on dissolved organic carbon fluxes in northern catchments: Insights from the North-Watch intercomparison Doerthe Tetzlaff, Sean K. Carey, Hjalmar Laudon, Chris Soulsby, Jan Seibert, Jim Buttle, Jeff McDonnell, Kevin McGuire, Jamie Shanley

The higher mid-latitudes of the Northern hemisphere are particularly sensitive to the influence of climate change as small differences in temperature determine the status of frozen ground, precipitation phase, and the magnitude and timing of snow accumulation and melt. An international inter-catchment comparison program, North-Watch, led by the University of Aberdeen, Scotland, seeks to improve our understanding of the sensitivity of northern catchments to climate change by examining their hydrological and biogeochemical responses. The catchments are located in Scotland (Mharcaidh, Girnock and Strontian), Sweden (Krycklan), the United States (Sleepers River, Hubbard Brook and HJ Andrews) and Canada (Catamaran, Dorset and Wolf Creek). In a first phase, the North-Watch program focused on how these catchments collect, store and release water. At most sites, ten years of daily precipitation, discharge and temperature were compiled and evaporation and storage calculated. Inter-annual and seasonal patterns of hydrological processes were assessed via normalized fluxes and standard flow metrics. At the annual-scale, relations between temperature, precipitation and discharge were compared, highlighting the role of latitude, wetness and frozen ground on streamflow response. The degree to which precipitation inputs are uncoupled to runoff relates to a catchment’s functional resistance. This resistance is in turn related to storage capacity, in that catchments with high resistance can store water over several months (or years) and release water gradually to the stream. The degree to which catchments can respond to and/or recover from perturbations (i.e. drought, extreme precipitation) suggests their resilience. While not a complete corollary with the notion of resistance, catchments exhibit a high resilience if they are able to keep their normal functioning (translating inputs to outputs) in light of changing inputs. The seasonal pattern and synchronicity of fluxes at the monthly scale provided insight into system memory and the role of storage. While some catchments rapidly translate precipitation into runoff, others exhibit considerable resistance, storing water for release many months after precipitation. Synchronicity and variance of rainfall-runoff patterns were characterized by the coefficient of variance of monthly fluxes and correlation coefficients.

In addition, North-Watch also aims to better understand how catchment DOC is being affected by climatic, land use and hydrological change. Analyses highlighted that hydro-climatic conditions have profound control on DOC on episodic, seasonal and inter-annual time scales across these northern catchments. Whilst there is a strong seasonality in runoff and DOC export among all catchments, it becomes successively more dominated by export during the spring towards the sites in colder regions. There is also decoupling between runoff and DOC export, with a generally lower relative export of DOC during winter and spring and higher relative export during late summer and fall. Results provide a conceptual framework for understanding the sensitivity of catchment hydrology and biogeochemistry to environmental change across northern catchments.

31 Stream directed airflow and anabatic/katabatic dynamics at a headwater stream in a Pacific North- Western Douglas-fir forest Iain Hawthorne1*, Mark S. Johnson2, and T. Andrew Black3

1Department of Earth and Ocean Sciences, University of British Columbia 2Institute for Resources, Environment and Sustainability and Department of Earth and Ocean Sciences, University of British Columbia 3The Faculty of Land and Food Systems, University of British Columbia

A limited understanding of the complex relationships between greenhouse gases evading surface water systems and subsequent atmospheric trace gas transportation make quantification of trace gas fluxes to and from streams extremely difficult. A better understanding is needed to help resolve ecosystem and catchment carbon (C) balances. Topography, vegetation cover, local and regional airflow patterns all affect the ultimate fate of trace gas fluxes. Eddy covariance and chamber flux measurement techniques are popular approaches for ecosystem C balance estimation, both are however difficult to use in complex Pst-15 Poster Abstracts non-homogenous terrain. In particular, the eddy covariance technique cannot measure the C content of air flowing underneath the eddy covariance measurement point and chamber data cannot easily be interpreted when measured from a stream, due to the influence of the chamber itself on such things as cross boundary diffusion gradients.

The University of British Columbia Biometeorology and Soil Physics group have been making eddy covariance and soil chamber C balance measurements at a 59-year-old Pacific North-Western Douglas- Fir stand (DF49) for over 10-years. The UBC Ecohydrology group has since 2007 been maintaining a water quality monitoring station at a weir on a headwater stream draining the catchment underneath the prevailing eddy covariance footprint. In April 2010 an R.M. Young 8100 Sonic anemometer was installed at the weir location at 2 m height to help characterize airflow patterns below the canopy and with respect to surface water drainage. In this summary, 10-days of airflow data collected above the stream channel were compared with sonic anemometer data collected at 2 m height on the eddy covariance tower upslope of the weir.

At the weir, the magnitudes of the 10 min average wind speeds were consistently low (< 1 ms-1 in all cases). There was a consistent downdraft of air, a semi-chaotic shifting between East/West wind directions (cross stream) and very apparent periodic shifting in the North/South (up and down stream) wind direction over the 10-day sample period. The shifting of the North/South wind vector is indicative of regional anabatic/katabatic airflow developing over the course of one day. Daily average wind vector analysis shows that there was a net negative flow measured for all wind vectors, indicating that there was a more prominent katabatic drainage flow down the stream channel. There is a positive uphill airflow driven by atmospheric heating during the day forcing air up the stream channel followed by a negative counter flow from atmospheric cooling at night. Generally the airflow speeds were lowest (0 ms-1) in the morning (6-8 am) and evening (4-6 pm) corresponding to the anabatic/katabatic airflow switch. Comparing the weir site data with the upslope data suggests that the stream acts as a directional channel collecting and steering dense cool air.

Continued data collection will allow better characterization of these interesting features and other unknowns across the seasons when vegetation structure changes and local and regional airflow patterns may be more or less pronounced. It also may support the argument that flux gradient approaches under development for headwater stream channels could help resolve imbalances between different ecosystem carbon balance measurement techniques.

32 Carbon drainage pathways in a Douglas-fir headwater catchment in the Pacific Northwest Mark S. Johnson1*and Iain Hawthorne2

1Institute for Resources, Environment and Sustainability and Department of Earth and Ocean Sciences, University of British Columbia 2Department of Earth and Ocean Sciences. University of British Columbia

The net ecosystem carbon balance (NECB) is defined by Chapin et al., (2006; Ecosystems 9: 1041-1050) as the difference between gross primary production and ecosystem respiration, minus additional carbon losses such as by hydrologic flowpaths. We are working in a study area that has been the focus of biospheric-atmospheric CO2 exchange using the eddy covariance (EC) technique for over 10 years. The footprint of the EC flux tower is spatially coincident with a 90 ha watershed and headwater stream draining over >80% of the EC flux tower. This is allowing an unusual opportunity to compare terrestrial and aquatic components of the carbon cycle. This presentation is focused on illustrating the carbon flowpaths that require quantification in order to calculate the NECB for the study catchment.

Carbon flowpaths in the watershed include dissolved, particulate and gaseous forms. The surface water draining the catchment contains flow-weighted mean concentrations of about 3 mg C L-1 as dissolved organic carbon (DOC), and about 3 mg C L-1 as dissolved inorganic carbon (DIC). Specific UV absorbance of DOC at 254 nm (SUVA254), a measure of the DOC aromaticity, was assessed in-situ by submerged spectrophotometer. SUVA254 was found to be strongly flow dependent, increasing by more than a factor of 3 during storm events. DIC is comprised of about 2 mg C L-1 as bicarbonate and

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-1 -1 1 mg C L as dissolved CO2. An additional 1.5 mg C L is transported as particulate organic carbon (POC). In total, about 8.5 mg C L-1 is transported out of the watershed in dissolved form by surface water.

However, there is also significant CO2 evasion within the baseflow-dominated surface water system, evidenced by the large disparity between groundwater pCO2 (average values of 31,000 ppm) and surface water pCO2 (average of 1,600 ppm). The CO2 in groundwater originates from terrestrial respiration on the landscape, and is transported laterally to the stream by drainage flowpaths. The quantification of this evasion flux and the identification of its fate is the topic of ongoing research. Key to its resolution is characterization of airflow within the catchment and along the stream channel (see Hawthorne et al., a partner poster at the 2010 CUAHSI Biennial Colloquium). Preliminary results to date suggest that predominant airflow drainage patterns follow the stream network, channelling stream-evaded CO2 down gradient and away from the flux tower.

33 Denitrification and the production of nitrous oxide in subtropical riparian zones Sarra E. Hinshaw* and Christine S. Fellows, Australian Rivers Institute, Griffith University

Riparian buffer zones play an important role in reducing nitrogen inputs to waterways, primarily through denitrification. However, there is concern and considerable uncertainty regarding the amount of nitrous oxide (N2O), an important greenhouse gas, produced by this process. Factors influencing denitrification potential, N2O production and the N2O/(N2O + N2) ratio in soils and stream sediments were investigated in three subtropical catchments. Paired sites contrasting well vegetated and sparsely vegetated conditions were sampled during both the wet and dry seasons in each catchment. The highest rates of denitrification and N2O production were observed in shallow soils with added nitrate. Within shallow soils, potential denitrification rates ranged from 0.51 to 10.08 mg N/kg dry soil.day and 0.10 to 9.28 mg N2O/kg dry soil.day for N2O production. Denitrification rates and N2O production from deeper soils were generally less than 1 mg N/kg dry soil.day. A consistent seasonal pattern was not observed, and both well and sparsely vegetated sites supported high denitrification rates within the shallow soils. Within stream sediments, denitrification rates ranged from 0 and 8.76 mg N2O/kg dry soil.day. N2O production was below detection limit within stream sediments. Observed N2O/(N2O + N2) ratios ranged from 0 to 1.11, however, were often greater than 0.50 in shallow soils with the addition of nitrate. Riparian zones in this experiment - indicated that high NO3 loading may exhibit high net N2O emissions, independent of vegetation cover, and management strategies to facilitate reduction to N2 gas are required.

34 Anthropogenic signatures in nutrient loads exported from managed catchments: Emergence of effective biogeochemical stationarity Nandita B. Basu, Georgia Destouni, James W. Jawitz, Sally E. Thompson, Natalia V. Loukinova, Amélie Darracq, Stefano Zanardo, Mary Yaeger, Murugesu Sivapalan, Andrea Rinaldo, and P. Suresh C. Rao*

Examining the impacts of large-scale human modifications of watersheds (e.g., land-use intensification for food production; hydrologic modification though extensive tile-drainage, etc.) on the hydrologic and biogeochemical responses, and ecological impacts at various scales has been the focus of monitoring and modeling studies over the past two decades. Complex interactions between hydrology and biogeochemistry and the need to predict responses across scales has led to the development of detailed process based models that are computation intensive and calibration dependent. Despite the perceived complexity, our overall hypothesis is that human modifications and intensive management of these watersheds have led to more predictable responses, typical of an engineered, less-complex system rather than natural, complex systems. Thus, simpler and more efficient approaches can be used in these systems for predicting hydrologic and biogeochemical responses.

It has been argued that human interferences and climate change may have contributed to the demise of hydrologic stationarity. However, our synthesis of observational data shows that anthropogenic impacts have also resulted in the emergence of effective biogeochemical stationarity in managed catchments. Long-term monitoring data from the Mississippi-Atchafalaya River Basin (MARB) and the Baltic Sea Drainage Basin (BSDB) reveal that inter-annual variations in loads (LT) for total-N (TN) and total-P (TP), and for geogenic constituents exported from a catchment are linearly correlated to discharge (QT), leading Pst-17 Poster Abstracts to temporal invariance of the flow-weighted concentration, Cf = (LT/QT). Emergence of this consistent pattern across diverse catchments is attributed to the anthropogenic legacy of accumulated nutrient sources generating memory, similar to ubiquitously present sources for geogenic constituents. These responses are characteristic of transport-limited systems. In contrast, in the absence of legacy sources in less-managed catchments, Cf values were highly variable.

We offer a theoretical explanation for the observed patterns at the event scale, and extend it to consider the stochastic nature of rainfall/flow patterns at annual scales. Our analysis suggests that (1) expected inter-annual variations in nutrient loads can be robustly predicted given discharge variations from hydro- climatic or anthropogenic forcing, and (2) water quality problems in receiving inland and coastal waters would persist until the accumulated storages of nutrients have been substantially depleted. The synthesis bears notable implications on catchment management and on global biogeochemical cycles.

35 Hydrostatic pumping as a mass transport mechanism during storm events and diel flow cycles Adam S. Ward* and Michael N. Gooseff, Department of Civil & Environmental Engineering, Penn State University

Commonly applied solute transport models do not include temporal or spatially dynamic hydraulic gradients between the stream and hyporheic zone, nor down-valley transport in the subsurface. Here, we present conceptual and numerical models coupling pseudo two-dimensional flow and solute transport models to illustrate the effect of these mechanisms on solute transport. Numerical simulations quantify down-valley transport, which would otherwise be interpreted as a mass loss to an unknown sink. Furthermore, this study illustrates pumping of stream water into and out of the hyporheic zone as a result of dynamic in-stream flow depths. This is a heretofore unidentified mechanism for moving solute beyond the typical ‘window of detection’ in stream tracer studies.

36 How do hyporheic flowpaths change as a result of in-channel restoration structure installation? Adam S. Ward1*, Michael N. Gooseff1, Anne Lightbody2, Sara Johnson3, and June Sayers4

1Department of Civil & Environmental Engineering, Penn State University 2Department of Earth Sciences, University of New Hampshire, Durham, NH 3St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 4St. Cloud State University, St. Cloud, MN

In-channel restoration structures are widely implemented as a strategy to restore the form and function of stream and riparian ecosystems, yet their impact on stream-aquifer interactions remains poorly understood. In-channel structures influence both static and dynamic pressures at the stream-aquifer interface, modifying hyporheic flowpaths. Here, we present pre- and post-structure solute tracer data collected during both baseflow (both conservative and reactive tracer) and bankfull (conservative tracer only) conditions at the Outdoor StreamLab in Minneapolis, MN. Preliminary results highlight spatial and temporal trends of exchange, and how these are affected by structure installation.

37 A quantitative methodology to assess the risks to human health from CO2 leakage into groundwater Erica Siirila*1,3, Reed Maxwell1,3, Alexis Sitchler2, and John E. McCray2,3

1 Department of Geology and Geological Engineering, Colorado School of Mines 2 Environmental Science & Engineering Division, Colorado School of Mines 3 Hydrologic Science & Engineering Program, Colorado School of Mines

Leakage of CO2 and associated gases into overlying aquifers as a result of geologic carbon sequestration (CGS) may have adverse impacts on aquifer drinking-water quality. Gas- or aqueous-phase leakage may occur due to transport via faults and fractures, through faulty well bores, or through leaky confining materials. Contaminants of concern include aqueous salts and dissolved solids, gaseous or aqueous- Pst-18 Poster Abstracts phase organic contaminants, and acidic gas- or aqueous-phase fluids that can liberate metals from aquifer minerals. This EPA and DOE funded research focuses on identifying drinking water sources susceptible to metal contamination from those aquifers that lie above current or proposed geologic carbon sequestration targets.

Here we present a quantitative risk assessment framework to predict potential human health risk from CO2 leakage into drinking water aquifers. This framework incorporates (1) a release of C02 into the drinking water aquifer; (2) mobilization of metals due to a decrease in pH; (3) transport of these metals downgradient to municipal receptors; and (4) exposure and health risk to individuals using this water for household purposes. Additionally, this framework is stochastic, incorporates detailed variations in geological and geostatistical parameters and discriminates between uncertain and variable parameters using a two-stage, or nested, Monte Carlo approach. This approach is demonstrated using idealized, yet realistic, aquifer characteristics and leakage scenarios. Finally, implications for ranking aquifer vulnerability due to geologic configuration, aquifer mineralogy, and leakage scenarios are discussed.

38 SWMM-based green infrastructure enhanced storm water modeling Ning Sun1* and Myrna Hall2*

1 Graduate Program in Environmental Science, SUNYESF 2 Center for the Urban Environment and Department of Environmental Studies, SUNYESF

A wide variety of Green Infrastructure (GI) practices are available for controlling urban stormwater quantity and quality. GI functions as onsite stormwater control, controlling runoff at the sources in a disaggregated and distributed network. Funded by the National Science Foundation (NSF) Urban Long- Term Research Area (ULTRA) grant, my study addresses how to simulate the net effect of combined on- site GI devices on stormwater reduction by presenting a methodology which integrates stormwater management goals, a hydraulic/hydrologic modeling program SWMM, and the spatial and physical information extracted from the geodatabase built in ArcGIS. Simulations were created for the sewershed near to the downtown Syracuse, where the frequent Combined Sewer Overflows (CSOs) has caused degraded water quality of Onondaga Lake. One of the primary objectives of my study was to test whether or not the simulation at a parcel scale or even household scale could greatly improve the model accuracy in simulating the CSOs in a small urban watershed. The micro-scale simulation results were also compared to the commonly used simulation scale (>100 acres) using the monitored flow data in the year of 2009. The results indicated that micro-scale level both captured the spatial reality of the site of interest and promoted a modular approach to modeling the larger watershed by aggregating spatial data and the associated analysis. In order to determine the net utility of decentralized GI facilities at the parcel scale, the GI simulation will be implemented at the parcel scale represented by a homogeneous land use and land cover type. The existing hydraulic objects (e.g., storage units, weirs) and hydrological objects (e.g. aquifers), combined with developed conductivity and curve numbers for various GI devices will be used to simulate the changes in the quantity of urban stormwater runoff on annual, seasonal and monthly time scales as a result of various GI implementations at the subcatchment scale, and in turn to identify the GI device of the best performance under local conditions.

39 Hydraulic modeling of discharge rating curves in urban streams Garth Lindner* and Andrew J. Miller, Department of Geography and Environmental Systems and Center for Urban Environmental Research and Education, University of Maryland, Baltimore County

Quantitative relationships used to convert recorded water levels to discharge records in urban streams are typified by high levels of uncertainty, particularly for flows near the upper end of the rating curve. This is because of the inherent difficulty of making direct discharge measurements during storms in urban watersheds with flashy runoff response. In this paper, we describe a modeling approach to support rating curves for a network of stream gages in the Baltimore, Maryland metropolitan region. We utilized TUFLOW, a finite difference model that solves a 2-D depth-averaged form of the Navier-Stokes equations, to simulate a range of flow conditions in each stream reach of interest. This model was chosen for three reasons: 1) its numerical stability permits the use of hydrographs characterized by a Pst-19 Poster Abstracts very rapid stream rise; 2) the model allows for the representation of urban infrastructure such as bridges and culverts in the computational grid; and 3) the model includes options for combined 1-d and 2-d flow domains as well as 2-d flow domains with multiple grid scales. High-resolution LIDAR data sets were merged with total-station field surveys of channel beds to capture the detailed topography of the streams and adjacent riparian zones. Simple input hydrographs were initially used as upstream boundary conditions, field-surveyed water surface gradients were used as the downstream boundary condition, and roughness values estimated in the field were used for the channel and overbank features. The stage- discharge relationship from model outputs was then extracted at the location of the stream gage. Field data used to test and adjust the model-based rating curves include direct discharge measurements at base flow and storm flows up to maximum wadeable depth; water surface profiles marked by flagging water levels along the stream during higher in-bank flows; and surveyed high-water marks recorded after floods. Matches between the model generated data and the field recorded data are remarkably close. The validated rating curves are then used to convert recorded stage records into discharge records, permitting further analysis into the behavior of the hydrologic system of a watershed. This method presents a means for the accurate generation of stage-discharge relationships when technical obstacles preclude the measurement of high flows for the upper end of discharge rating curves.

40 Water balances in urbanized metropolitan Baltimore Aditi Bhaskar1* and Claire Welty1 1 Department of Civil and Environmental Engineering and Center for Urban Environmental Research and Education, University of Maryland, Baltimore County

Human influence and land use change can modify natural water balances in many ways, including through groundwater and surface water withdrawals for water supply and agriculture, leakage from water distribution pipes, infiltration of groundwater into sewer pipes, and water import and export between watersheds for water supply or wastewater treatment. In our case, we are trying to quantify water balances of gauged metropolitan Baltimore watersheds, which span a gradient of urbanization. How significant are the human components of the water balances in these watersheds as compared to the natural components? The 56 watersheds were delineated using the NED and NHD data products. For evapotranspiration estimates we used the land surface model Mosaic product from NLDAS. Precipitation data came from a PRISM data product. Streamflow data used are from USGS gauges. The water balances have been calculated for water year 2004. Similar to undisturbed areas, there is a strong correlation between watershed area and discharge. However, there are large disparities (ranging from positive to negative) in the difference between precipitation and the sum of evapotranspiration and discharge. These disparities are related to imperviousness (as a measure of urbanization) and watershed size. Further work will consider leakage from water distribution pipes in water services areas and water supply import and export. The relative importance of difference components of the water cycle will inform the future work of surface-subsurface watershed modeling of the Baltimore metropolitan region.

41 Implementation of an integrated distributed model of the Chesapeake Bay Watershed using ParFlow Alimatou Seck1*, Claire Welty1, and Reed Maxwell2 1Department of Civil and Environmental Engineering and Center for Urban Environmental Research and Education, University of Maryland Baltimore County 2Department of Geology and Geological Engineering and International Groundwater Modeling Center, Colorado School of Mines

The Chesapeake Bay is currently listed as an impaired water body and is the object of intensive restoration efforts to mitigate water quality issues, particularly those related to the transport of nutrients and sediments into the Bay. Groundwater discharge contributes significantly to the annual flows of Chesapeake Bay tributaries and is presumed to contribute to the observed lag time between the implementation of management actions and the environmental response in the Chesapeake Bay. The EPA Phase 5 Chesapeake Bay Watershed model, based on HSPF, simulates river flow and associated transport and fate of nutrients and sediments and is used as a decision support tool. However, this model Pst-20 Poster Abstracts does not provide a mass-conserving representation of the groundwater fluxes in the watershed. As an alternative, this study aims to develop an integrated, distributed model of the Chesapeake Bay Watershed using ParFlow v3. Here we document initial implementation issues. We consider a model domain of 382,976 sq km in size with land surface elevations ranging from 0 m to 1700 m. 10 km to 500 m square grid size were considered, with various combinations of DEM preprocessing and channel representation. Overland flow tests using the land surface slopes were carried out to determine optimal gridding and parameterization to represent the topography and river channels. Initialization test runs in a fully coupled surface subsurface mode for a 4km and a 2 km grid size with respectively 43,084,800 (176*136*1800) cells and 172,339,200 (352*272*1800) cells are presented. The model runs were carried out on Tara, an 86-node distributed memory cluster purchased in 2009 by the UMBC High Performance Computing Facility (www.umbc.edu/hpcf). Each node of the cluster features two quad-core Intel Nehalem X5550 processors (2.66 GHz, 8 MB cache), 24 GB memory, and a 120 GB local hard drive. A strong scalability study was completed using up to 512 nodes and demonstrated an excellent performance.

42 Integrating a surface water-groundwater model with robust estimates of baseflow: Bertrand Creek Watershed, BC Cindy Starzyk* and Leslie Smith, Department of Earth and Ocean Sciences, University of British Columbia, Vancouver BC Canada

Understanding the nature and controls of surface water - groundwater interactions is of utmost importance as increased need is placed on managing these watershed–scale resources in an integrated manner. This study takes advantage of the capabilities offered by HydroGeoSphere, a coupled surface water – groundwater modelling code, in determining the groundwater contribution to streamflow when combined with robust estimates of baseflow. HydroGeoSphere is a 3-D physically based model which accounts for overland and channel flow as well as flow through both the saturated and unsaturated zones in a fully-integrated manner. An intensive field data collection program within the Bertrand Creek Watershed in BC, Canada provides the basis on which the watershed model has been developed. The Bertrand Creek Watershed is an agriculture-rich watershed which has exhibited reduced baseflows attributed to groundwater extractions and within recent years has had segments of the creek go dry. The field program employed the installation of weirs at successive stream gauging locations to provide estimates of gains or losses to creek flow over reach segments. Direction of the surface water/groundwater exchange flux at specific locations along the creek were obtained from nested mini- piezometers installed within the creek bed. Model parameters were calibrated to baseflow conditions within the watershed, including flow at the downstream outlet, incremental gains in stream flow along creek segments, and measured groundwater levels in wells within the underlying aquifers. The field program identified locations along the creek length which changed from losing to gaining as well as stationary locations where the flux direction changed overt time. Results will be presented for a 2 km2 subsection of the 45 km2 watershed where a focused effort was placed on characterizing the spatial and temporal heterogeneity of the baseflow contribution. The integrated model is successfully able to identify gaining, losing and flow-through sections of the creek and to model changes in the direction of the exchange flux based on large precipitation events and lowering of the shallow water table.

43 Influences of subsurface heterogeneity and vegetation cover on soil moisture, surface temperature, and evapotranspiration at hillslope scales Adam L. Atchley* and Reed M. Maxwell, Hydrologic Science and Engineering Program, Department of Geology and Geologic Engineering, Colorado School of Mines

Physical mechanisms are at the root of determining hydrologic response at all scales. Here, the physical mechanisms linking subsurface heterogeneities to soil moisture and resulting land surface energy feedbacks to the atmosphere are examined at the hillslope scale using a fully coupled surface- subsurface-land-surface model, ParFlow-CLM (PF.CLM). A hillslope with a heterogeneous subsurface and uniform topography was modeled using summer atmospheric conditions and a single precipitation event. Patterns of subsurface hydraulic conductivity are shown to govern soil moisture distribution at the hillslope scale following precipitation. This variability in soil moisture is closely linked to the variability in land surface energy feedbacks. Evaportranspiration and soil surface temperature changes throughout Pst-21 Poster Abstracts day and night cycles reflect soil moisture patterns and how variability in soil moisture determines the ability of the soil surface to gain and store energy from atmospheric inputs. The role of vegetation in limiting subsurface soil moisture and land energy communications is also examined. Results show that hillslope soil moisture is first established after a substantial precipitation event by patterns in vertical hydraulic conductivity while later on in the dry-down period vegetation exerts greater control on the land surface energy fluxes and controls the rate of hillslope dry-down. Heterogeneous distributions of plant communities can then add a further complexity to the patterns of soil water-atmospheric communications.

44 Quantifying the effects of subsurface heterogeneity on hillslope runoff using a stochastic approach Steven B. Meyerhoff* and Reed M. Maxwell, Hydrologic Science and Engineering Program, Geology and Geological Engineering Department, Colorado School of Mines, Golden Colorado

We use the fully integrated model Parflow to evaluate the role of heterogeneity on hillslope runoff production and baseflow. Simulations were generated with idealized, high-resolution hillslopes configured with and without baseflow. Heterogeneous, correlated random fields were used to create spatial variability in hydraulic conductivity. Ensembles of multiple realizations were used to determine an average surface water outflow for a given hillslope as a function of rainfall rate and degree of subsurface heterogeneity. Outflow from slopes without baseflow show typical hydrograph patterns which agree with previous studies of Hortonian runoff generation. However, baseflow cases show a much different runoff behavior, with very little sensitivity to the variance of hydraulic conductivity. A technique is presented that explicitly interrogates individual realizations to perform accurate hydrograph separation between overland and subsurface flow. This technique allows determination of the contributions from variance of overland and baseflow for each case. This hydrograph separation technique is used to show that the variance of heterogeneity has a role in determining the proportion of overland and subsurface flow, even when effective hillslope behavior might be reached. This method is also used to evaluate to other hydrograph separation techniques and demonstrates that the recursive filter class of techniques can accurately proportion flow for some cases. We then apply our baseflow results and hydrograph separation to a Florida watershed, the Santa Fe River Basin.

45 An integrated approach to investigate the hydrological behavior of the Santa Fe River Basin, north central Florida Vibhava Srivastava*1, Wendy D. Graham2, Reed M. Maxwell3, Jonathan B. Martin4, and Matthew J. Cohen5

1 Department of Agricultural & Biological Engineering, University of Florida 2 Water Institute, University of Florida 3 Department of Geology and Geologic Engineering, Colorado School of Mines 4 Department of Geologic Sciences, University of Florida 5 School of Forest Resources and Conservation, University of Florida

The Santa Fe River Basin (SFRB) consists of three linked hydrologic units: the upper confined region (UCR), semi-confined transitional region (Cody Escarpment, CE) and lower unconfined region (LUR). Contrasting geological characteristics among these units affect streamflow generation processes. In the UCR, surface runoff and surficial stores dominate whereas in the LCR minimal surface runoff occurs and flow is dominated by groundwater sources and sinks. In the CE region the Santa Fe River (SFR) is captured entirely by a sinkhole into the Floridan aquifer, emerging as a first magnitude spring 6 km to the south. In light of these contrasting hydrological settings, developing a predictive, basin scale, physically- based hydrologic simulation model remains a research challenge. This ongoing study aims to assess the ability of a fully-coupled, physically-based three-dimensional hydrologic model (PARFLOW-CLM), to predict hydrologic conditions in the SFRB. The assessment will include testing the model's ability to adequately represent surface and subsurface flow sources, flow paths, and travel times within the basin as well as the surface-groundwater exchanges throughout the basin. In addition to simulating water fluxes, we also are collecting high resolution specific conductivity data at 10 locations throughout the river. Our objective is to exploit hypothesized strong end-member separation between riverine source Pst-22 Poster Abstracts water geochemistry to further refine the PARFLOW-CLM representation of riverine mixing and delivery dynamics.

46 Implementing complexity criteria into diagnostic evaluation methods for water balance models (in a large national dataset) Guillermo Martinez and Hoshin Gupta, Department of Hydrology and Water Resources, University of Arizona

Robust methods for model identification of hydrologic models in large datasets are needed to identify knowledge gaps and evaluate future impacts of hydroclimatic variability at national scale. While high- resolution models can provide information about detailed spatial variability, lumped models of water balance are a first step in hypothesis testing that can help to quantify dominant catchment processes and detect systematic biases in the data. With a view to improving methods for evaluation and selection of parsimonious catchment model formulations, we study the performance of a monthly water balance model for 700 catchments across the United States. Via a diagnostic first iteration, a detailed description and explanation of differences in model performance was obtained. This step helped to show how error decomposition can be used to understand the behavior of commonly used performance measures, and guide the design of methods that allow a more objective comparison of model performance among different catchments. In our second iteration, we implement a measure of model complexity to identify parsimonious variations of the initial model structure based on information from the parameter sets generated during model calibration. These new results are used to evaluate whether the improvements in structure selection result in relationships among model performance, parameters and catchment descriptors that are better applicable in watershed classification and model regionalization.

47 A methodology for evaluating alternative long-term monitoring networks for water quality in large watersheds with uncertain weather Sue Nee Tan and Christine Shoemaker, Cornell University

We propose a methodology for determining the best locations for long-term water quality and flow monitoring locations in watersheds to provide better information for the prediction of hydrological responses to weather. The improved predictions will enable watershed managers to make better decisions regarding land use in the watershed. The methodology is applied to the 1200 km2 Cannonsville watershed for which we have over a decade of flow, sediment and phosphorus data. The Cannonsville watershed in upstate New York is one of the largest drinking water reservoirs for New York City. This crucial watershed has historically experienced serious water quality issues due to large phosphorus runoff from dairy farms in the watershed. The chemistry of the water reaching surface water is strongly affected by its pathway over and through the land surface. If the current water quality conditions continue to worsen, the city of New York must build a water filtration plant with an initial cost on the order of billions of dollars. Long-term monitoring of the water quality in this watershed through a monitoring network is a critical component of the management of this watershed. Currently, there are five USGS flow stations and two NYSDEC water quality stations in the watershed area. Several sensor network placement scenarios were investigated in our study. Each scenario is a set of different location and number of new flow and water quality monitoring stations to be placed in the catchment. The Soil and Water Assessment Tool (SWAT) hydrologic simulation model was run with hypothetical “true” watershed parameters to determine the “true” watershed output (time series data for flow, phosphorus and sediment concentrations) after rainfall. For each of the scenarios, a subset of the observed output values for flow, phosphorus, and sediment were obtained. These output values were used to calibrate new parameters for the SWAT model. The SWAT model was then run using the calibrated parameters. Then the simulated output was compared to the previously defined “true” output to identify which scenario represents the best improvement over the current monitoring configuration. This comparison is based upon calibrated model accuracy over an ensemble of weather patterns.

Pst-23 Poster Abstracts

48 Modeling variable source area hydrology on flow and phosphorus transport predicted by a SWAT model for the Cannonsville Watershed Josh Woodbury, Christine A. Shoemaker, Dillon Cowan, and Zach Easton, Cornell University, Ithaca, NY

Variable source area (VSA) hydrology is the concept that runoff generating locations vary in both time and space, depending on the time of year, rainfall, temperature and topography. VSAs are driven by saturation excess overland flow. Since many water quality models , such as SWAT (Soil and Water Assessment Tool), use some form of the curve number equation to predict runoff, these models often fail to accurately describe VSA hydrology. This study looks at the impact of incorporating VSA hydrology into a SWAT model. The results of the SWAT model with VSA hydrology are compared to results from a normal SWAT model and show little difference in goodness of fit. The models are calibrated against daily measured flow, sediment and phosphorus. The VSA model can be used to estimate an upper bound on the impact of moving phosphorus-heavy land use out of the wettest areas.

49 Hydrologic function in large floodplains April E. Newman*1, Richard F. Keim1, and Louis J. Thibodeaux2

1 Agricultural Center, School of Renewable Natural Resources, Louisiana State University 2 Cain Department of Chemical Engineering, Louisiana State University

At various scales, spatiotemporal landscape heterogeneity and connectivity drive processes and mechanisms of nutrient dynamics and flood duration that ultimately define hydrologic function in floodplains. Although many processes and mechanisms have been observed and documented in the literature, the current understanding of how these factor into overall hydrologic function remains poorly understood. Examples include geomorphic controls formed by natural levees and scroll topography that affect not only surface flowpaths but also hyporheic flow patterns that respond to pressure differentials across small-scale hydraulic gradients. Hyporheic corridors facilitate mixing of surface and shallow groundwater, and rates of exchange tend to increase with increasing scale. Similarly, geomorphic features may contribute to the formation of groundwater ridges during flood recession and after rainfall; these ridges control flowpaths and potentially have a pronounced effect on spatial variability of solute concentrations at a mesoscale. Here, we identify potential controlling processes of floodplain hydrologic function and discuss the role of scale in choosing methods to test hypotheses.

50 The Hydrometeorology Testbed (HMT): Developing new tools to address water resources challenges in a changing climate Tim Schneider1, Marty Ralph1, John McGinley1, Allen White1, Lynn Johnson1,2

1 NOAA Earth System Research Laboratory 2 Department of Civil Engineering, University of Colorado Denver

NOAA’s HMT is a long-term project seeking to accelerate the development and infusion of advanced hydrometeorological technologies, models, and scientific results from research to forecasting operations of the NWS and its partners. This paper summarizes HMT’s design, deployment, outcomes to date and future plans.

The first HMT deployment has targeted California’s flood-vulnerable American River basin and the “atmospheric rivers” that are key factors in extreme precipitation and flooding along the US west coast. “HMT-West” concentrates on improving extreme event predictions. HMT’s goals have required the formation of interdisciplinary teams to develop, deploy and test new observation systems, numerical weather models, model ensembles, display systems and decision support tools. The major subjects being explored are quantitative precipitation estimation and forecasting, probabilistic forecasting, snow level tracking and hydrologic applications. New verification methods have been developed for extreme precipitation and snow level.

Pst-24 Poster Abstracts

HMT has led to the development of: • New verification methods for extreme precipitation and snow level. • Significant advances in our understanding of processes leading to extreme rainfall in complex terrain. • A Coastal Atmospheric River Monitoring & Early Warning System. • State-of-the-art precipitation analyses in complex terrain, utilizing both standard and polarimetric radar observations; surface gage data; and specific vertical profile of reflectivity (VPR) adjustments to correct for the bright band. • A number of observing system technology advances, including a low-cost, snow-level radar and mobile atmospheric river observatories (AROs), stream level and soil moisture monitoring and a variety of advanced radar signal processing techniques. A number of results from the five-year HMT-West project have obtained wide acceptance by NWS forecasters and their federal, state, local and other partners. A number of these have been enabled through the EFREP partnership with the State of California, directed to implementing key findings from HMT. Lessons learned from HMT-West are guiding the design of the next regional implementation of HMT, scheduled for the southeastern US. Like the HMT-West it will involve participants from the various federal and state water agencies, as well as academic researchers who can utilize the HMT data sets for advanced research on the water cycle. 51 Assessing possible changes in flood frequency due to climate change in mid-sized watersheds in New York State, USA Stephen B. Shaw* and Susan J. Riha, Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY

Merz and Bloschl (Water Resources Research, 44: W08432) have recently suggested that “flood frequency statistics” may need to give way to “flood frequency hydrology”, arguing that flood frequency analysis has long focused on the estimation problem (the statistics) but has neglected the underlying physical processes behind the flooding (the hydrology). Using 50+ years of historical discharge and meteorological data from three watersheds in different physiographic regions of New York State, USA, we identify differing causes of annual maximum discharges occurring on the same streams in New York state, namely annual maximum discharges caused by: 1) large rainfall events, 2) sizable snow melt, and 3) any other processes (primarily, moderate rainfall on very wet soils). Somewhat surprisingly, from this analysis we find that less than 20% of annual maximum discharges are associated with the largest annual rainfalls. This suggests that at least in this region, there may need to be a more careful consideration of claims that flooding will increase due to increased rainfall intensities associated with a warming climate. Thus, to more quantitatively assess the role of different flood causative mechanisms under a changing climate, we also model observed floods using compound frequency distributions that assume annual maximum discharges can result from any of the three primary causes: rainfall, snowmelt, moderate rain on wet soils.

52 A comparison of distributed temperature sensing to traditional methods of evaluating groundwater influx to streams Martin A. Briggs and Laura K. Lautz, Department of Earth Sciences, Syracuse University Jeffrey M. McKenzie, Department of Earth and Planetary Sciences, McGill University

There are currently several methods available for determining both the spatial distribution and magnitude of groundwater inputs to streams. These range from physical flow gauging to introduced and natural tracers, all of which have varied levels of resolution and suitability to specific system conditions. We compared the results of traditional methods (fluorescent dye dilution gauging, acoustic Doppler velocimeter (ADV) differential gauging, and geochemical end-member mixing) to Distributed Temperature Sensing (DTS) data collected using fiber-optic cables installed along 900 m of Nine Mile Creek in Syracuse, New York, USA during low-flow conditions (discharge = 1.4 m3s-1). Temperature measurements were made using an Agilent Distributed Temperature Sensor which recorded temperature at 1.5 m increments over the length of a fiber optic cable installed along the thalweg at the sediment/water interface. The 24 hr mean and standard deviation of these measurements indicated one region of focused groundwater input to the stream of ~ 0.07 m3s-1. Additionally we found that the Pst-25 Poster Abstracts groundwater inflow estimates were sensitive to differential heating and integration time, with the poorest estimates being generated at the time of peak solar input (early afternoon). A constant rate injection of Rhodamine WT dye also identified a gain of groundwater over the same region with magnitude of ~ 0.07 m3s-1, though this method was less certain due to a possible lack of total stream tracer plateau. Geochemical samples were collected every 50 m along the reach, and the highly saline groundwater end- member was sampled from shallow piezometers installed in the streambank, and from deeper wells which had higher variability in dissolved concentrations. Mixing models between stream water and groundwater sampled from the piezometers using calcium and chloride both generated estimated focused groundwater inflows of ~ 0.07 m3s-1 over the same region as the heat and dye methods. In contrast to these results, physical flow gauging discharge measurements made approximately every 100 m using a handheld FlowTracker ADV failed to identify/quantify the focused groundwater input. This was due to the high variability in discharge estimates, which had a standard deviation of 0.13 m3s-1, but resulted in no net change over the 900 m reach. The uncertainty of each discharge estimate generated with the ADV exceeded the inflow in equation (5% total stream flow), and was likely increased by stream turbulence due to high velocities, extensive macrophyte growth and non-ideal channel bedform. These results indicate that the use of natural tracers such as heat and geochemical mixing can yield spatially and quantitatively refined estimates of relatively modest groundwater inflow even in large streams, whereas physical flow gauging may not capture these dynamics due to non-ideal conditions and inherent uncertainty. DTS heat tracing in particular provided the finest spatial characterization of focused inflow, and may be more universally applicable than geochemical methods which depend on a unique and consistent groundwater end member.

53 Using distributed temperature sensing (DTS) as tool for identifying thermal refugia in headwater streams Christine E. Hatch1, Scott W. Tyler1, David Boughton2, Laura Belica3

1 Department of Geological Sciences and Engineering, University of Nevada, Reno 2 NOAA Fisheries, Ecology Div., SW Fish. Sci. Ctr. 3 Great Basin National Park, Baker, Nevada

Temperature has long been used as an indicator of ecosystem health and suitability for aquatic species, particularly in sensitive areas crucial to the survival of declining important fish populations. Typically, temperature surveys are of long duration but very limited in spatial extent. In recent years, considerable attention has been paid to assessing the ecology, and particularly the thermal regimes, of remaining near- pristine headwater catchments. These studies hope to assess habitats for native species restoration and identify key stream reaches where reproduction takes place, as well as seasonal thermal refugia supporting species survival and local thermal heterogeneities in larger stream systems that allow migratory pathways to persist. Raman-spectra distributed temperature sensing (DTS) along fiber-optic cables provides a unique opportunity to measure continuous longitudinal stream temperatures for hundreds of meters, allowing researchers to assess groundwater inflows, thermal refugia, and temperature heterogeneities at an extremely detailed spatial scale. In this compilation of studies, we present data from three semi-arid catchments (Strawberry Creek in the Great Basin, Squaw Creek the Sierra Nevada, and Horse Creek in the coastal range of California) to investigate seasonal and diurnal thermal behavior, the feedback between hydrology, geology and ecosystem function, and most importantly, the identification and spatial variability of thermal refugia.

Pst-26 Poster Abstracts

54 Assessing spatial variability of soil thermal properties using distributed temperature sensing Lucas Williamson1*, Mark Hausner1; Christine Hatch1; Scott Tyler1; Richard Zartman2; Jop Jansen3; Philip Stive3; Nick van de Giesen3

1 University of Nevada, Reno 2 Texas Tech University 3 Delft University of Technology

Applications of Raman Spectra temperature sensing, or Distributed Temperature Sensing (DTS) have steadily increased in number and diversity in recent years. DTS allows for temperature measurements that are nearly continuous in time and space. In theory, the temporal evolution of temperature vertically within a soil column can be used to determine thermal properties, and even extrapolate soil moisture information. Recent work (Steele-Dunne et al. 2010) have demonstrated that qualitative estimates of soil moisture and its spatial variability can be assessed using buried fiber-optic cables as thermometers. Inversion of time-varying temperatures for moisture content at a single depth of burial carries a large uncertainty both due to uncertainty in the depth of burial and surface boundary temperatures. Using several depths of measurement can significantly reduce the uncertainty (C. Sayde 2008) however multiple cable installations add significant logistical complexity. In this study, we describe a low-cost multiple cable installation system capable of installing fibers at 3 shallow depths with minimal soil disturbance. Located at the University of Nevada, Reno, Main Station Farm, three DTS fiber optic cables were installed in a vertical profile at approximate depths of 2, 7, and 12 centimeters over a 100m transect. During the ~10 day experimental period, both diel and multi-day signals of thermal response were detected, as climatic conditions varied from clear and warm to stormy and windy. Gravimetric soil moisture sampling was also conducted throughout the experiment as well as a co-located eddy covariance tower. Significant horizontal variability in soil temperature were observed during daytime hours, and likely result from variability in surface vegetation cover. In addition to traditional geostatistical analysis, numerical simulation of heat transport will be presented with the goal of developing estimates of both the variability in soil moisture content as well as the variability in soil heat flux.

55 Monitoring the temperature profile in a solar pond using a vertical high-resolution distributed- temperature-sensing system Francisco Suárez1*, Jazmín E. Aravena2, Mark B. Hausner1, Amy E. Childress2, and Scott W. Tyler3

1Graduate Program of Hydrologic Sciences, University of Nevada, Reno 2Department of Civil and Environmental Engineering, University of Nevada, Reno 3Department of Geological Sciences and Engineering, University of Nevada, Reno

A solar pond is a shallow water body that allows collection and storage of solar energy for a long period of time. It consists of three distinct layers: the upper convective zone, the non-convective zone, and the lower convective zone. The upper convective zone is a thin layer of cooler and fresher water. The non- convective zone has gradients in temperature and salinity, and acts as an insulator for the lower convective zone. The lower convective zone is the layer where temperature and salinity are the highest. The solar radiation that reaches the lower convective zone is stored in this zone. In solar ponds it is important to measure temperature on fine spatial and temporal scales to detect stratification or different hydrodynamics regimes. Distributed temperature sensing (DTS) is an approach available to provide high spatial and temperature resolution. A high spatial resolution DTS system was utilized to monitor the vertical temperature profile inside an experimental solar pond during both the initial heating and continuous operation of the pond, i.e., when heat is extracted from the pond. Temperatures were measured each 1.1 cm vertically and in time averages as short as 10 s. Temperature resolution as fine as ±0.04 ºC was obtained when the data were collected at 5-min intervals and using single-ended measurements. Prior to any heat extraction, equilibrium temperatures of 34 and 45 ºC were reached in the bottom of the solar pond for radiation levels at the water surface of 110 and 243 W m-2, respectively. The high-resolution DTS system made it possible to estimate that heat was extracted at a rate of 139 W

Pst-27 Poster Abstracts from the solar pond. Using the DTS system, mixing and stratification were clearly observed within the solar pond.

56 Evidence of seasonal convective mixing in Devils Hole, Death Valley National Park, Nevada Mark B. Hausner1, Scott W. Tyler2, Kevin P. Wilson3, D. Bailey Gaines3, and Michael R. Bower4

1Graduate Program of Hydrologic Sciences, University of Nevada Reno 2Department of Geologic Sciences and Engineering, University of Nevada Reno 3Death Valley National Park, Pahrump, Nevada 4Bighorn National Forest, Sheridan, Wyoming

Devils Hole is a window into the carbonate aquifer located in the Amargosa Valley of southwestern Nevada, and is the sole habitat for the endangered Devils Hole pupfish (Cyprinodon diabolis). The system comprises a cavernous deep pool of unknown depth (divers have descended as far as 130 m) and a shallow shelf (20 – 80 cm deep) that provides a substrate for pupfish spawning and algae growth. While water temperatures within the deep pool are near the upper threshold for pupfish (consistently around 33.5°C), temperatures on the shallow shelf are highly variable, and can reach 37° C during the summer and 26° C in the winter. To better understand the thermal regime of Devils Hole, a fiber-optic distributed temperature sensor has been deployed periodically to measure water temperatures, both in the deep pool and on the shallow shelf. Vertical temperature profiles from four different deployments (January, February, July, and September, 2009) in the deep pool are presented and compared. Evidence of seasonal convective mixing in Devils Hole (similar to seasonal turnover in a lake) is presented, and the forces driving the mixing and stabilization are discussed.

57 Client-side Web services for water resources management: Russian River case study Kevin (Wei-Te) Hsu and Lynn E. Johnson, Department of Civil Engineering, University of Colorado Denver

The objectives of this project are to study how web services can be applied for user-side water management in a client-server system. Web service is a standardized way of integrating Web-based applications using the Extensible Markup Language (XML), Simple Object Access Protocol (SOAP), Web Service Description Language (WSDL) and Universal Description, Discovery and Integration (UDDI) open standards over an Internet protocol backbone. Unlike traditional client/server models, web services do not provide the user with a GUI. Instead, Web services share business logic, data and processes through a programmatic interface across a network. The applications interface with each other, not with the users. Developers can then add the Web service to a GUI (such as a Web page or an executable program) to offer specific functionality to users. For example, the Consortium of Universities for the Advancement of Hydrologic Science, Inc (CUAHSI) (http://www.cuahsi.org) has developed the Hydrologic Information System (HIS) to improve access to hydrologic data. CUAHSI-HIS provides water data web services so that users can download the water data of USGS and EPA. For this project the Russian River in California was used as a case study. Web services of CUAHSI-HIS were used to download streamflow and water temperature data for fishery management of the Russian River. For example, streamflow level and water temperature are important habitat conditions for salmonoids; if the streamflow is too low and/or the water temperature too high the salmonoids may die. A client-side application was developed to illustrate data monitoring, analysis and publication supportive to fisheries management by local Russian River watershed agencies. The downloaded water data was stored in an ArcGIS personal geospatial database and table select functions were used to select data that met critical threshold conditions of flow (<75 cfs) and temperature (>20C). A local user website was created using Net Visual Basic to publish the downloaded water data and analysis results. Google Earth Keyhole Markup Language (KML) was used to display the GIS data such as hydrographic data and observation site locations. Results of the project highlight that most of water data provided by server-side websites have different formats (e.g.,text, XML, and CVS) and database models. These differences increase the difficulty for the user-side’s applications. For example, if the water data downloaded from different websites have different Pst-28 Poster Abstracts formats, then the user needs to covert the data to a particular format for their application. A recommendation is to standardize the data formats and database models so as to increase the performance of user sides’ applications. 58 The WATER Machine: A large format water education system for insights into water across interfaces Wayne E. Woldt1*, Rachael Herpel2, Alan Corr3, Sharon Skipton4

1 Biological Systems Engineering and School of Natural Resources 2 UNL Water Center, UNL Extension, and NU Rural Initiative 3 West Central Research and Extension Center, Lexington 4 Southeast Research and Extension Center, Lincoln/Omaha

A mobile water resources education system has been developed to travel across Nebraska and deliver engaging educational programs on one of our most important natural resources. As such, the WATER (WAter Teaching, Extension and Research) Machine Mobile Educational System consists of a mobile trailer equipped with a large format, physically-based, ground and surface water model along with current/topical water related educational displays. Through the WATER education system, individuals become immersed in active multimedia learning in which they experience the movement and energy of water in a large-scale setting. The educational goal is for youth, the general public, and water users to understand the occurrence of groundwater, the interface of groundwater/surface water, irrigation management, wellhead management, and the protection of Nebraska’s water resources for future generations; resulting in responsible use of Nebraska’s most valuable resource. As with any learning tool, the key is to match the eye-catching wonder of the WATER Machine with knowledgeable and engaging educators who can help make what individuals see relevant and meaningful to them while also broadening their scope of understanding. For example, an urban resident may recognize the impact of runoff to a lake, and then go on to understand how lakes interface with groundwater and the potential water quality implications of this. A groundwater irrigator will recognize that decisions to apply water can have implications for streamflow, and then go on to understand how intermittent confining layers can impact groundwater flow. The WATER Machine consists of a large format, physical water model that is placed on a mobile platform, and hauled to site venues using a dual axle trailer. The approximate scale of the model is 6' long x 18” deep x 1" wide. The model includes a scenic landscape across the top to provide a sense of spatial scale relative to depth and horizon. The model has the ability to depict, in a very visual and engaging manner, complex concepts such as: surface and groundwater interaction, wellhead protection, urban and agricultural water use and conservation, groundwater aquifer structure, artesian aquifers, hydraulic gradient, and pollution vulnerability and movement. The model works with flowing water and incorporates the use of pumping wells, injection wells, liquid dyes, and will be operated through audience interaction with the educator. Water movement is provided through the use of variable speed peristaltic pumps.

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Name Index to Poster Abstracts

Al-Gamal ...... Pst-10 Lundquist ...... Pst-3 Atchley ...... Pst-21 Mahat ...... Pst-1 Basu ...... Pst-17 Martinez ...... Pst-23 Bhaskar ...... Pst-20 McEnery ...... Pst-11 Biggs ...... Pst-8 Meyerhoff ...... Pst-22 Briggs ...... Pst-25 Newman ...... Pst-24 Chen ...... Pst-10 Nolin ...... Pst-1 Cowie ...... Pst-12 Raleigh ...... Pst-2 de Linage ...... Pst-6 Reager ...... Pst-6 Duncan ...... Pst-14 Schneider ...... Pst-24 Ferguson ...... Pst-7 Seck ...... Pst-20 Flores ...... Pst-5 Shaw ...... Pst-25 Fryar ...... Pst-11 Siirila ...... Pst-18 Gleeson ...... Pst-6 Srivastava ...... Pst-22 Hatch ...... Pst-26 Starzyk ...... Pst-21 Hausner ...... Pst-28 Suárez ...... Pst-27 Hawthorne ...... Pst-15 Sun ...... Pst-19 Hinshaw ...... Pst-17 Tan ...... Pst-23 Hsu, Chengmin ...... Pst-4 Tetzlaff ...... Pst-15 Hsu, Kevin (Wei-Te) ...... Pst-28 Voepel ...... Pst-13 Hwang, Syewoon ...... Pst-3 Voss ...... Pst-7 Hwang, Taehee ...... Pst-14 Ward ...... Pst-18 Ivanov ...... Pst-13 Weider ...... Pst-9 Jacobs ...... Pst-9 Williams ...... Pst-7 Johnson ...... Pst-16 Williamson ...... Pst-27 Kumar ...... Pst-4 Woldt ...... Pst-29 Kustu ...... Pst-8 Woodbury ...... Pst-24 Lindner ...... Pst-19 Zarnetske ...... Pst-12 Lo ...... Pst-2

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9th St. 9th !$25 Walnut St.

18 20 11 th 11 119 Bed & Breakfast Pearl Street Mall Canyon Blvd. 7 AlpsViele Boulder Canyon Inn • 303.444.5445 • 800.414.2577 !' Lake

15 Lehigh 8 The Bradley • 303.545.5200 • 800.858.5811 Boulder Creek Path 12% Arapahoe Ave. 8# Cherryvale Rd. Cherryvale

Blvd. 93 Greenbriar Inns, Motels & Lodges Hotels 1 Best Western Boulder Inn • 303.449.3800 • 800.233.8469 9 Boulder Broker Inn • 303.444.3330 • 800.338.5407 2 Best Western Golden Buff Lodge • 303.442.7450 • 800.999.2833 10 Boulder Marriott • 303.440.8877 • 800.228.9290 3 Boulder Creek Quality Inn & Suites • 303.449.7550 • 888.449.7550 11 Boulder Outlook • 303.443.3322 4 Boulder Mountain Lodge • 303.444.0882 • 800.458.0882 12 Courtyard by Marriott • 303.440.4700 • 800.321.2211 5 Boulder University Inn • 303.442.3830 • 800.258.7917 13 Homewood Suites by Hilton • 303.499.9922 • 800.CALLHOME 6 Colorado Chautauqua Association • 303.442.3282, ext. 11 14 Hotel Boulderado • 303.442.4344 • 800.433.4344 15 Millennium Harvest House • 303.443.3850 • 800.545.6285 16 Residence Inn by Marriott-Boulder • 303.449.5545 • 800.331.3131 17 St Julien Hotel & Spa • 720.406.9696 Dining

Dining

Nestled on the eastern slope of the Rocky Mountains, Boulder is known for its unique setting, friendly residents, cultural arts and incredibly diverse dining experiences.

THE BOULDER DUSHANBE TEAHOUSE The Boulder Dushanbe Teahouse is a rare, handcrafted gift from Boulder’s sister city, Dushanbe, Tajikistan. With its eclectic international menu, breathtaking artwork and charming ambiance, the teahouse is a perfect gathering place to relax and enjoy a cup of tea.

BOULDER RESTAURANT LISTING Boulder boasts more than 250 restaurants featuring local, regional and international cuisine. For dining assistance, please contact the Boulder CVB for a free Boulder Restaurant Listing. Options include, but are not limited to:

American Ethiopian Italian Mexican Caribbean French Japanese Organic Chinese Indian Korean Thai Continental Irish Mediterranean Vietnamese

Boulder has an incredible array of dining choices, from ethnic and health food restaurants to funky spots, popular brewpubs, locals' hangouts and elegant dining for that special occasion. Both Boulder Weekly's "2004 Best of Boulder" and The Daily Camera’s "2004 Readers' Choice Awards" offer insight into Boulder's culinary favorites:

Whole Foods was Boulder Weekly's biggest victor in 2004, winning "Best Salad Bar," "Best Fresh Produce," "Best Grocery Store" and "Best Health Food Store," as well as runner-up for "Best Vegetarian." Boulder Weekly also gave top honors to The Full Moon Grill as the "Best Overall Restaurant" in Boulder.

Curious which restaurants won titles from both The Daily Camera and Boulder Weekly? Moe's Bagels proudly holds the coveted "Best Bagel" title, Sunflower topped the list as "Best Vegetarian" and the Cream Puffery took home "Best Dessert" by both papers this year. The "Best Sandwich" can be devoured at Salvaggio's, the "Best Breakfast" at Lucile's, and, of course, the "Best Margarita" can be sampled at the Rio Grande.

In the mood for ethnic cuisine? The Golden Lotus reportedly has the "Best Chinese," Laudisio serves the "Best Italian," Juanita's mixes up the "Best Mexican," Sushi Zanmai prepares the "Best Japanese," and Khow Thai whips up the "Best Thai." If you would rather prepare your own fixin's at home, swing by Whole Foods, the "Best Grocery Store" in town.

On a health kick? Take advantage of the healthy edibles at either Breadworks or the Boulder Bread Company, owners of this year's "Best Bakery" titles. No time to sit down and eat? Swing by Siamese Plate on the go for some of Boulder's "Best Takeout."

Want to sample a few local microbrews? Old Chicago's offers the "Best Beer Selection," while The West End Tavern is said to be the "Best Bar." Mountain Sun taps this year's "Best Microbrew” and if your looking for a great wine selection, Trilogy was voted “Best Wine Selection” by Boulder Weekly.

For a peek at Boulder's local favorites, head to Turley's for a shot of wheat grass, stop in at Glacier Homemade Ice Cream for Boulder's "Best Ice Cream" or drop by Mountain Sun to sample the "Best Hamburger" in town. The "Best Outdoor" dining can be found at The Mediterranean or West End Tavern which provides unparalleled views of the Flatiron Mountains. Dining

Boulder Restaurant Guide Service: B=breakfast; L=lunch; D=dinner; Br=brunch

Restaurant Address Phone # Cuisine Service Handicap Accessible Capactiy Private Room 14th St. Bar And Grill 1400 Pearl St. 303.444.5854 American Bistro L;D • 90 Abo's Pizza 637 S. Broadway 303.494.1274 Pizza L;D Abo's Pizza 2761 Iris 303.443.1921 Pizza L;D • Central/South Aji 1601 Pearl St. 303.442.3464 L;D American Ajuaa 627 S. Broadway 303.494.9204 Mexican L;D • 147 Alexander's and Levorio's 1718 Broadway 303.443.3856 Mexican/Itallian L;D Creekside Café Alexander’s Restaurant 1650 Broadway 303.444.6699 New Mexican L;D • 25 Allison Espresso & Pastry 1521 Pearl St. 303.442.3065 Coffee/Pastry B;L;D Coffee/Sandwich/ Amante Coffee 4580 N. Broadway 303.448.9999 Pastry Antica Roma 1308 Pearl 303.449.1787 Italian L;D • Applebee’s Neighborhood 1906 28th Street 303.442.8813 American L;D; Br • 230 Grill Asian Deli 2829 28th St. 303.449.7950 Vietnamese L;D 40 Attic Bar and Bistro 949 Walnut 303.415.1300 American L;D Bacaro 921 Pearl St. 303.444.4888 Italian L;D • 90 Baked in Boulder 1729 15th St. 303.444.1773 Pizza L;D BD's Mongolian BBQ 1600 Pearl St. 303.443.6803 Mongolian Stir Fry L;D • Belgian Bakery 3267 28th St. 303.449.7240 Bakery B;L Big Daddy Bagels 4800 Baseline Rd. 303.554.0193 Bagel Sandwich B;L;D • 35 BJ’s Pizza Grill & Brewery 1125 Pearl St. 303.402.9294 American L;D • 180 Blue Fine Pastries 1918 Pearl St. 720.565.9092 Pastries B;L • 8 1800 Broadway Bombay Bistro 303.444.4721 Indian L;D • (One Boulder Plaza) BookEnd Espresso Café 1115 Pearl Street 303.440.6699 Coffeehouse/Bakery B;L;D • 100 B;L;D;B Boulder Broker Restaurant 555 30th St. 303.449.1752 Continental • 200 r Boulder Café 1247 Pearl St. 303.444.4884 American L;D; Br • 175 Boulder Chili/Chilly 1622 Broadway Boulder Chop House & 947 Walnut St. 303.443.1188 American L;D • 217 20 Tavern American/ 24;36; Boulder Cork 3295 30th St. 303.443.9505 L;D • 250 Steakhouse 65 Boulder Creek Market 1437 Arapahoe Ave. 303.444.7167 Deli L • 15 Boulder Dushanbe Tea 1770 13th St. 303.442.4993 International B;L;D • 100 House Boulder Pizza Exchange 1546 28th St. 303.449.6363 Italian L;D Boulder’s Dinner Theatre 5501 Arapahoe Ave. 303.449.6000 American D • 290 Brasserie Ten Ten 1011 Walnut 303.998.1010 French L;D • 107 Breadworks Café 2644 Broadway 303.444.5667 American B;L;D • 40 Brickhouse BBQ Grill 1346 Pearl St. 303.440.6555 Barbecue L;D 1301 Pennsylvania Buchanan's 303.440.0222 Sandwich/ Pastry L;D • 50 Ave. Buff Restaurant 1725 28th Street 303.442.9150 American B;L • 150

Restaurant Grid as of 4.1.06 Dining

Boulder Restaurant Guide Service: B=breakfast; L=lunch; D=dinner; Br=brunch

Restaurant Address Phone # Cuisine Service Handicap Accessible Capactiy Private Room 40;70; Buffalo Sports Bar & Grille 800 28th St. 303.443.3322 American B;L;D • 130 100 1235 Pennsylvania 49/2 Burnt Toast 303.440.5200 American B;L;D Ave. 7 5280 Spine Rd. Café Blue 303.530.4345 American L;D • 50 #103 Café Food 2079 30th St. 303.443.9239 American L • 35 Sandwich, salad, Café Bravo 2425 Canyon Blvd. 303.440.5737 B;L;D • 20 burrito Café Gondolier 1738 Pearl St. 303.443.5015 Italian L;D • 133 Café Siena One Boulder Plaza 303.546.0269 American B;L • 30 Caffe Sole 637 S. Broadway 303.499.2985 Coffee/Desserts B • 50 Camille's Sidewalk Café 1710 Pearl St. 303.444.9727 Sandwich/soup L;D • Carelli’s of Boulder 645 30th St. 303.938.9300 Italian L;D • 100 70 Casa Alvarez 3161 Walnut 303.546.0630 Mexican L;D • 350 70 Celestial Seasonings Cafe 4600 Sleepytime 303.581.1201 American B;L • 150 Chautauqua Dining Hall 900 Baseline Rd. 303.440.3776 American B;L;D 65 Sandwich/Soup/ Cheba Hut 1315 College Ave. 303-413-3494 L;D Salad Vietnamese/ Cheers 2850 Iris Ave. 303.440.0810 L;D • 120 Chinese Cheesecake Factory 1401 Pearl St. 303.546.0222 Varied L;D • 250 Chez Thuy Restaurant 2655 28th St. 303.442.1700 Vietnamese L;D • 150 Chili’s Grill & Bar 1729 28th St. 303.449.9682 American L;D • 225 China Gourmet 3970 N. Broadway 303.440.3500 Chinese L;D • 60 25 Chinatown Express 1121 Broadway 303.444.8886 Chinese L;D Chipotle Mexican Grill 919 Pearl St. 303.554.9383 Mexican L;D • 75 CiCi's Pizza 4800 Baseline Rd. 720.304.0403 Pizza/pasta L;D • City Street Bagels 3070 28th St. 303.442.0049 American B;L • 20 Conor O’Neill’s 1922 13th St. 303.449.1922 Irish L;D • 200 Corner Bar & Cafe 2115 13th St. 303.442.4560 American L;D • 85 Cosmo's Pizza 30th & Baseline 303.447.3278 Pizza/salads L;D • 40 Crosswalk Café & Deli 1148 Pearl St. 303.443.9032 American B;L;D • 40 D’Napoli Ristorante 835 Walnut 303.444.8434 Italian D • 40 Da Gabi Cucina 3970 N. Broadway 303.786.9004 Northern Italian L;D • 80 25 Daddy Bruce's Bar-B-Que 2000 Arapahoe Ave. 303.449.8890 BBQ L;D 15 & Catering Dark Horse 2922 Baseline Rd. 303.442.8162 American L;D • 422 Delhi Darbar 826 Pearl St. 303.443.3929 Indian L;D 60 Deli Zone 2900 Valmont Rd. 303.447.9349 Sandwiches L;D • 15 Deli Zone 4800 Baseline Rd. 303.499.9213 Sandwiches L;D • 15 Denny’s Restaurant 2905 Baseline Rd. 303.447.0080 American B;L;D • 160 Dolan’s Restaurant 2319 Arapahoe Ave. 303.444.8758 American L;D • 250 60; 35 Dot’s Diner 1333 Broadway 303.447.9184 American Diner B;L • 80 Dot’s Diner 2716 28th St. 303.449.1323 American Diner B;L • 80 Efrains 1630 N. 63rd St. 303.440.4045 Mexican L;D • Egg & I Boulder 2574 Baseline Rd. 303.494.0555 American B;L

Restaurant Grid as of 4.1.06 Dining

Boulder Restaurant Guide Service: B=breakfast; L=lunch; D=dinner; Br=brunch

Restaurant Address Phone # Cuisine Service Handicap Accessible Capactiy Private Room Einstein Brother Bagels 1693 28th St. 720.565.0413 Bagel Sandwich B;L;D • 35 15/2 Einstein Brother Bagels 2400 Baseline Rd. 303.543.1525 Bagel Sandwich B;L;D • 0 El Taco Loco 1664 30th Street 303.247.1562 Mexican L;D • 100 Espressoria 2116 Pearl St. 303.247.0124 Lightfare B;L;D • 30 Public Library-10th Espress-OH! 303.444.1876 Sandwiches L • 25 & Canyon Falafel King Restaurant 1314 Pearl 303.449.9321 Mid-Eastern L;D • 50 Fatty J's 770 28th St. 303.442.6666 Pizza L;D • 20 Fiasco's Mexican Grill 2690 Baseline Rd. 303.200.0469 Mexican L;D • Flagstaff House Restaurant 1138 Flagstaff Rd. 303.442.4640 Continental D • 100 20 Foolish Craig’s 1611 Pearl St. 303.247.9383 American B;L;D • 50 Frasca Food & Wine 1738 Pearl St. 303.442.6966 North Eastern Italian D • Fresh Grains 2520 N. Broadway 303.938.1998 American B;L • 39 Full Moon Grill 2525 Arapahoe Ave. 303.938.8800 Italian D • Gemini Thai Kitchen 1630 30th St. 303.447.3321 Thai L;D • Glacier Homemade Ice 3133 28th St. 303.440.6542 Ice Cream L;D Cream Glacier Homemade Ice 1350 College Ave. 303.440.6542 Ice Cream L:D Cream Global Chili/Chilly 1622 Broadway 303.546.9000 Chili, Ice Cream L;D Golden Lotus 1964 28th St. 303.442.6868 Chinese L;D • 285 25 8735 N. Foothills Greenbriar Inn 303.440.7979 American D; Br • 250 10-200 Hwy Half Fast Subs 1215 13th St. 303.449.0404 American L;D • 100 Haoway Chinese Café 1678 30th Street 303.442.5115 Chinese L;D • 20 1220 Pennsylvania Hapa on the Hill 303.447.9883 Asian Fusion/Sushi L;D • Hapa Sushi Grill & Sake Ave. 1117 Pearl St. 303.473.4730 Asian Fusion/Sushi L;D • 90 Bar Harpo's Sports Grill 2860 Arapahoe Av 303.444.9464 American/Mexican L;D • Himalayas Restaurant 2010 14th St. 303.442.3230 Tibetan / Indian L;D 86 50 House of Chang 6565 Gunpark Dr. 303.581.9958 Chinese L;D • 125 yes Hungry Toad 2543 N. Broadway 303.442.5012 American / English L;D;Br • 100 3075 B Arapahoe Il Pastaio 303.447.9572 Italian L;D • 20 Ave. Illegal Pete’s 1320 College Ave. 303.444.3055 Mexican/Burritos L;D Illegal Pete’s 1447 Pearl St. 303.440.3955 Mexican/Burritos L;D • 60 Intl. House of Pancakes- 140/ 1675 28th St. 303.444.2115 American B;L;D • IHOP 60 Jalino's 1647 Arapahoe Av 303.443.6300 Italian L;D 6 Jamba Juice 3052 Arapahoe Av 303.247.1170 Smoothies/soup B;L;D • 10 Japango 1136 Pearl St. 303.938.0330 Japanese L;D • Jax Fish House 928 Pearl St. 303.444.1811 Seafood D • Jazzy's Crab Shack 2719 Iris St. 303.544.0069 Seafood D • Jet's Espressoria 2116 Pearl St. 303.247.0124 Sandwich/soup B;L;D • 30

Restaurant Grid as of 4.1.06 Dining

Boulder Restaurant Guide Service: B=breakfast; L=lunch; D=dinner; Br=brunch

Restaurant Address Phone # Cuisine Service Handicap Accessible Capactiy Private Room Jill's 900 Walnut St. 720.406.9696 American B;L;D • Jin Chan 1915 28th St. 303.442.7166 Chinese L;D • 120 60 French /Italian John’s Restaurant 2328 Pearl St. 303.444.5232 D • 60 60 /Spanish /American Juanita’s Mexican Food 1043 Pearl St. 303.449.5273 Mexican L;D 150 Juice Stop 2525 Arapahoe Av 303.444.4667 Juice Bar B;L;D • Jus' Burritos 1116 13th St. 303.448.9517 Mexican B;L 50 JW’s Steakhouse 2660 Canyon Blvd 303.440.8877 American B;L;D • Karma Cuisine 1911 Broadway 303.440.9292 Vegetarian L;D K’s China 1325 Broadway 303.413.0000 Chinese L;D • 130 Kerrigan's 2500 30th St. 101 303.524.3425 American-Irish B;L;D • Khow Thai Café 1600 Broadway 303.447.0273 Thai L;D • 40 Kim Food to Go 1325 Broadway 303.442.2829 Vietnamese L;D Korea House 2750 Glenwood 303.449.1657 Korean L;D • 45 KT’s BBQ Outback 2675 13th St. 303.442.3717 BBQ L;D • 16 KT’s Hick’ry Pit BBQ 75th & Arapahoe 303.786.7608 BBQ L;D • 65 22 1800 Broadway French, L'Absinthe Restaurant 303.442.6777 L;D; Br • 110 #150 Mediterranean La Hacienda 1606 Conestoga 303.440.8565 Mexican B;L;D • 120 30 La Mariposa Restaurant 2845 28th St. 303.444.2922 Mexican L;D Taqueria L'Atelier 1739 Pearl Street 303.442.7233 French L;D • 50 30;60; Laudisio 2785 Iris Ave. 303.442.1300 Italian L;D • 225 120 400/ Lazy Dog Sports Grill 1346 Pearl St. 303.440.3355 American L;D • 200 Le Francais Bakery & Cafe 2570 Baseline Rd. 303.499.7429 French Bakery B;L;D • 150 60 Le Peep Restaurant 2525 Arapahoe Av 303.444.5119 American B;L • 150 30 Lee Yuan Chinese Cuisine 4800 Baseline Rd. 303.494.4210 Chinese L;D • 48 Lick Skillet Bakery 5340 Arapahoe 303.449.7775 Bakery/Health Food B;L;D • 30 Lucile’s 2124 14th St. 303.442.4743 BBQ/Cajun/Creole B;L 65 Lucky's Café 3980 Broadway 303.444.5007 American/Greek B;L Mamacitas 1149 13th St. 303.443.2300 Mexican L;D 35 Marie’s Cafe 2660 Broadway 303.447.0320 American B;L • 75 Masa Grill 1265 Alpine 303.440.9511 Mexican L;D • 100 Mataam Fez Moroccan 2226 Pearl St. 303.440.4167 Moroccan D 80 30;50 Restaurant Mateo 1837 Pearl St. 303.443.7766 Country French L;D • 50 Maywah Chinese & Chinese & 2500 Baseline Rd. 303.499.8225 L;D • 80 Vietnamese Restaurant Vietnamese Mediterranean 1002 Walnut 303.444.5335 Mediterranean L;D • 200 50 3075 Arapahoe Moe's Bagels 303.442.4427 Bagel Sandwich Ave.

Restaurant Grid as of 4.1.06 Dining

Boulder Restaurant Guide Service: B=breakfast; L=lunch; D=dinner; Br=brunch

Restaurant Address Phone # Cuisine Service Handicap Accessible Capactiy Private Room Bagel Moe's Bagels 2650 N. Broadway 303.444.3252 B;L;D 30 Sandwich/Pizza Moongate Asian Bistro 1628 Pearl St. 720.406.8888 Asian L;D • 49 Mountain Sun Pub & 1535 Pearl St. 303.546.0886 American L;D • 70 Brewery Murphy’s Bar & Grill 2731 Iris 303.449.4473 American L;D • 180 60 Mustard's Last Stand 1719 Broadway 303.444.5841 American L;D • Naked Fish 1346 Pearl 303.440.6555 Seafood D • 300 200 Narayan's Nepal Nepali/Indian/ 4800 Baseline Rd. 303.499.2234 L;D • 49 49 Restaurant Tibetan Nick-N-Willy's Take-N-Bake 4800 Baseline Rd. 303.499.9898 Pizza Nick-N-Willy's Take-N-Bake 801 Pearl St. 303.444.9898 Pizza Noodles & Co. 1245 Alpine Ave. 303.440.4340 Noodles/pasta L;D • 49 Noodles & Co. 2770 Pearl St. 303.444.5533 Noodles/pasta L;D • 54 Noodles & Co. 2850 Baseline 303.247.9978 Noodles/pasta L;D • 50 North Broadway Coffee 4479 Broadway 303.449.3663 Variety B;L;D • 100 7 Shop Old Chicago 1102 Pearl St. 303.443.5031 Italian L;D • 257 70 Olive Garden 2685 Pearl St. 303.546.6506 Italian L;D • 300 30 Orchid Pavilion 1050 Walnut 303.449.4353 Chinese L;D • 200 Original Pancake House 2600 Canyon Blvd. 303.449.1575 Breakfast B • Paradise Bakery & Café 1207 Pearl St. 303.442.3965 Bakery Parkway Restaurant 4700 Pearl St. 303.447.1833 American B;L • 90 25 Pasta Jay’s 1001 Pearl St. 303.444.5800 Italian L;D • 80 Ping's Favorite 1635 28th Street 303.449.0783 Chinese L;D • 25 Pita Pit 1509 Arapahoe Ave. 303.443.7482 Pita Sandwich/soup B;L Pizza Colore 1336 Pearl St. 303.444.8958 Pizza L;D Playa Azul 1600 38th St. 303.545.9400 Mexican L;D • 470 50 4670 Broadway, Proto's Pizza 720.565.1050 Pizza L;D Ste. C110 Contemporary/ Q’s Restaurant 2115 13th St. 303.442.4880 B;L;D • 100 25 American Qdoba 1625 28th St. 303.440.1006 Mexican L;D • Ras Kassas Ethiopian 2111 30th St. 303.447.2919 Ethiopian D • 60 Restaurant 38472 Boulder 80;100 Red Lion Inn 303.442.9368 Continental D;Br • 250 Canyon Dr. ;250 Red Robin Burgers & 2580 Arapahoe Ave. 303.442.0320 American L;D • 380 Spirits Emporium RedFish New Orleans 20; 50; 2027 13th St. 303.440.5858 Creole L;D; Br • 225 Brewhouse 75 Burgers/Salads/ Republic of Boulder 1095 Canyon Blvd. 303.443.1460 L;D • 200 Soups Rhumba 950 Pearl St. 303.442.7771 Caribbean L;D • 177 45

Restaurant Grid as of 4.1.06 Dining

Boulder Restaurant Guide Service: B=breakfast; L=lunch; D=dinner; Br=brunch

Restaurant Address Phone # Cuisine Service Handicap Accessible Capactiy Private Room Rincon Del Sol 2350 Arapahoe Ave 303.442.0541 Mexican L;D • 165 Rio Grande Mexican 1101 Walnut St. 303.444.3690 Mexican L;D • 250 5290 Arapahoe Ave Rock N'Soul Café 303.443.5108 Sand/Soup L;D #I 5290 Arapahoe Ave Royal Peacock 303.447.1409 Indian L;D • #B American / 4720 Table Mesa Rudi’s Restaurant 303.494.5858 International / L;D;Br • 60 27 Dr. Vegetarian Saffron 2005 18th St. 303.544.6060 Indian L;D • 75 Salvaggio’s Italian Deli 2609 Pearl St. 303.938.1981 Italian B;L;D • 10 Salvaggio's Italian Deli 1107 13th St. 303.448.1200 Italian B;L;D Salvaggio's Italian Deli 1397 Pearl St. 303.545.6800 Italian B;L;D Sam's Chinese Kitchen 5360 Arapahoe Ave. 303.447.3529 Chinese L;D Santiago's Mexican 1325 Broadway 303.245.9365 Mexican L;D Restaurant Serrano’s Southwestern 40- 6525 Gunpark Dr. 303.530.7423 Mexican L;D • Grill 60 Sherpa's Rest. & Bar 825 Walnut 303.440.7151 Indian L;D Siamese Plate 1575 Folsom 303.447.9718 Thai/Japanese L;D • 70 10 Siamese Plate To Go 3033 28th St. 303.444.3133 Thai/Japanese L;D • Sidney's Cappuccino and Bagels/Pastries, 1375 Walnut St. 303.939.9052 B;L 20 Art Bar Salads, Sandwiches Sink 1165 13th St. 303.444.7465 Variety/ American L;D • 230 25; 90 Snarf's 2049 Pearl St. 303.444.7766 Sandwiches L;D 10 Snarf's 5304 Arapahoe Ave. 303.444.3404 Sandwiches L;D Southern Sun Pub and 627 S. Broadway 303.543.0886 Pub fare L;D • 160 Brewery South Side Walnut Café 673 S. Broadway 720.304.8118 American B;L • 80 Spicy Dragon 4479 N. Broadway 303.449.3663 Chinese D Sandwich/salad/ Spicy Pickle 2660 Pearl St. 303.413.0707 L;D soup Sumida’s 1575 Folsom 303.449.8404 Japanese/Sushi L;D • 10 Sunflower 1701 Pearl St. 303.440.0220 Organic / American L;D • 40 Sushi Tora 2014 10th St. 303.444.2280 Japanese L;D • Sushi Zanmai / Sake 1221 Spruce 303.440.0733 Japanese L;D • 110 6;16 Zanmai Taj Restaurant 2630 Baseline Rd. 303.494.5216 Indian L;D 125 30 Tandoori Grill 619 S. Broadway 303.543.7339 Indian L;D Chinese/ Taste of Saigon 1635 28th St. 303.449.0783 L;D • 110 20 Vietnamese 1801 13th Street Tea Spot 303.442.4832 Tea/Coffee/Bakery B;L;D • #170 Restaurant Grid as of 4.1.06 Dining

Boulder Restaurant Guide Service: B=breakfast; L=lunch; D=dinner; Br=brunch

Restaurant Address Phone # Cuisine Service Handicap Accessible Capactiy Private Room Terrace Maya 4929 N. Broadway 303.443.9336 Mexican L;D • 45 The Kitchen 1039 Pearl St. 303.544.5973 New American B;L;D • 70 The Grindstone Coffee 4593 N. Broadway 303.444.5886 Bakery, sandwiches The Reef Piano Bar & Grill 1801 13th Street 303.209.3740 Caribbean/ Cuban D • Thunderbird Burgers 1087 14th St. 303.449.9990 Sandwiches L;D • 15 Thyme on-the-Creek 1345 28th St. 303.443.3850 Continental B;L;D • 85 Tom’s Tavern 1047 Pearl St. 303.442.9363 American L;D • 100 Tra Ling’s Oriental Cafe 1305 Broadway 303.449.0400 Chinese L;D Trattoria on Pearl 1430 Pearl Street 303.544.0008 Italian L;D • Smoothies/ Traveler's Juice & Java 1932 14th St. 303.444.4849 B;L sandwiches Trilogy Wine Bar 2017 13th St. 303.473.9463 D 607-A South Tsing Tao 303.494.6228 Chinese L;D • 80 Broadway Turley’s 2805 Pearl St. 303.442.2800 American B;L;D • 175 Twin Teriyaki 2720 Canyon 303.546.0094 Japanese L;D Vicki's Parkway 4700 Pearl St. 303.447.1833 American B;L Village Coffee Shop 1605 Folsom 303.442.9689 American B;L • Wahoo's Fish Taco 2790 Pearl St. 303.473.9072 Mexican L;D Walnut Brewery 1123 Walnut 303.447.1345 American L;D; Br • 450 30 Walnut Cafe 3073 Walnut 303.447.2315 American B;L • 65 30 West End Tavern 926 Pearl St. 303.444.3535 BBQ/American L;D Organics, Whole Foods Market 2905 Pearl 303.545.6611 B;L;D • 15 Vegetarian Organics, Wild Oats Market 2584 Baseline Rd. 303.499.7636 B;L;D • 10 Vegetarian Organics, Wild Oats Market 1651 Broadway 303.499.7636 B;L;D • 10 Vegetarian Wilderness Pub @ Rockies 2880 Wilderness Pl. 303.444.8448 American L;D • 98+ 35 Brewing Co. Wing Zone 1310 College Ave 303.544.9464 Wings Wok & Roll Teriyaki 2900 28th St. 303.449.6555 Japanese L;D • 90 Yuko Asia 1175 Walnut St. 720.974.0388 Japanese L;D • Gourmet Zolo Grill 2525 Arapahoe Ave. 303.449.0444 L;D • 94 Southwestern

Restaurant Grid as of 4.1.06