Tunneling Through Karstic Rocks - How Engineering Geology needs Hydrogeologic input and logic

 

Paul Marinos

 

The 2010 Jahns Distinguished Lecturer

 

(Jan 22, 2010, UTSA ESE Graduate Seminar)

 

Although limestone and most carbonate rocks exhibit good geotechnical behavior, karstic conditions may induce hazards during tunneling operations and these may evolve into huge problems. Ground water and the crossing of voids and caverns, whether empty or filled, are the main problems.  In order to estimate the probability of encountering such conditions and be prepared to face them, a thorough hydrogological study should complement the traditional site investigation program. This study has to embrace the whole hydrogeologic basin of the karstic aquifer, with background knowledge of the geologic history - the tectonic and paleogeographic evolution. In the lecture, hydrogeologic models are discussed depending on the internal karstic geometry of the aquifer and the position of the tunnel, either in the transfer or the inundation zone. Each model is associated with its own tunneling particularities in terms of hazards and countermeasures.

The measures for the confrontation of the problems are presented and discussed in terms of both groundwater inflow and dealing with voids, filled or empty. In many instances probing ahead of the tunnel face is imperative. The lecture is illustrated by a number of significant recent tunneling experiences from important tunnels around the world.

 

BIO

 

Dr Paul Marinos has been named the 2010 Jahns Distinguished Lecturer. The Association of Environmental & Engineering Geologists (AEG) and the Engineering Geology Division of the Geological Society of America (GSA) jointly established the Richard H. Jahns Distinguished Lectureship in 1988 to commemorate Jahns and to promote student awareness of engineering geology trough a series of lectures offered at various locations around the country. Richard H. Jahns (1915 – 1983) was an engineering geologist who had a diverse and distinguished career in academia, consulting and government.

 

Dr Paul Marinos received a Mining Engineering degree from the School of Mines of the National Technical University of Athens, Greece in 1966, a postgraduate degree in Applied Geology from the University of Grenoble, France, and his Doctorate in Engineering Geology from the same University in 1969. He worked for French and Greek design and construction companies until 1977 and then was elected as Professor at Democritus University in Northern Greece. Since 1988 Dr Marinos has been Professor of Engineering Geology in the School of Civil Engineering in the National Technical University of Athens and has served as head of the Geotechnical Section of the School for several years. From 2001 to 2004 and from 2006 to 2008 he was the Director of a Graduate Course in Tunneling and Underground Construction. He was a visiting Professor in the Geology Department of the University of Grenoble (1987) and of the School of Mines in Paris (2003).

 

Dr Marinos is a member of AEG and GSA and fellow of the Geological Society of London. He is a past President of the International Association of Engineering Geology and the Environment (IAEG), immediate past president of the Geological Society of Greece and honorary member of the International Association of Hydrogeologists (IAH).

 

Dr Paul Marinos has received several awards, including the Hans Cloos medal of IAEG, and the Andre Dumont medal of the Geological Society of Belgium. He was selected for the presentation of named lectures, including the 6^th Glossop Lecture in London (2002), the 19^th Rocha Lecture in Lisbon (2002), the 33^rd Cross Canada Lectures Tour (2005), and the Rock Mechanics annual Lecture in Madrid (2006).

 

Dr Marinos and his team conduct research on a variety of applications of geology to engineering, mainly rock mass characterization, weak rock properties and behavior, with special emphasis to tunnel design. His work also covers landslides, dam geology, and engineering in karstic terrain. His other significant interest is the protection of historic monuments and archeological sites. Dr Marinos has authored or co-authored over 300 papers in journals or major conference proceedings. He was a key or invited lecturer in more than 40 conferences or special events. He has given lectures to University Courses or Workshops, among them the Federal Technical University (EPFL) in Lausanne, Switzerland, the Polytecnico of Turin, Italy, the University of Durham, U.K., the University of Coimbra, Portugal, the University of Kobe, Japan, the Black Sea University Romania, the Aristotle University of Thessalonica, Greece, and the Griffiths University, Australia. He has edited proceedings published by international publishers. Dr Marinos is a member of the Editorial Board of a number of prominent journals as “Engineering Geology”, “Bulletin of the International Association of Geology”,” Landslides”, “Environmental Geology”, “Rock Mechanics” and from 2009 “Environmental and Engineering Geosciences”.

 

Dr Paul Marinos has extensive industrial experience having served as consultant, independent reviewer and member of consulting boards or panel of experts on major civil engineering projects in Greece, Ecuador, France, India, Iran, Israel Jordan, Morocco, Portugal, Saudi Arabia, South East Asia, Spain, Sweden, and Turkey.

The Effect of Roof Material on the Quality of Harvested Rainwater

Mary Jo Kirisits

Department of Civil, Architectural, and Environmental Engineering

The University of Texas at Austin

(Feb 5, 2010, UTSA ESE Graduate Seminar)

The pressing need for sustainable freshwater supplies has increased the use of roof-based rainwater collection systems for potable applications.  Although rainwater harvesting systems may be relatively simple to construct, various sources of contamination within the collection system can negatively affect water quality.  For instance, harvested rainwater quality is affected by the roofing material on the catchment surface.  The main objective of this research was to provide information to the rainwater harvesting community in Texas regarding the impact of roofing material on harvested rainwater quality.

In this study, five pilot-scale roofs (asphalt-fiberglass shingle, Galvalume® metal, concrete tile, cool, and green) were equipped with rainwater sampling devices to collect the “first flush” and the water after the first flush. Generally, the first flush contained the highest concentrations of microbial and chemical contaminants, indicating that the quality of harvested rainwater improved with roof flushing. However, the rainwater harvested after the first flush did contain some contaminants at concentrations above primary EPA drinking water standards (including turbidity, total coliform, and fecal coliform) and secondary EPA drinking water standards (including iron and aluminum).  This indicates that harvested rainwater must be treated prior to potable use.

Based on the pilot-scale studies, none of the roofing materials emerged as the clearly superior choice in terms of the quality of the rainwater harvested after the first flush. However, green roofs do not appear to be the best candidates for rainwater harvesting.  Although the rainwater harvested after the first flush from the green roof consistently had the lowest values of total suspended solids, turbidity, nitrite, aluminum, iron, copper, and chromium, it also had the highest values of dissolved organic carbon (DOC); if disinfected by chlorination, the high DOC concentrations could lead to high concentrations of disinfection by-products. Rainwater harvested after the first flush from the metal and cool roofs yielded higher turbidity values than did the shingle roof, which might be attributed to their non-porous surfaces. The metal roof did not always yield higher concentrations of metals in the harvested rainwater as compared to other roofing materials; for instance, aluminum and iron concentrations in rainwater harvested after the first flush were consistently higher from the concrete tile roof as compared to the metal roof.

While metal and tile roofs are commonly recommended for rainwater harvesting, our limited data set suggests that asphalt-fiberglass shingle and cool roofs also could be considered for this purpose.  In the next phase of the research, we will utilize the shingle, metal, tile, and cool roofs to examine the quality of treated harvested rainwater (e.g., cartridge filtration and disinfection with chlorine or ultraviolet light). 

The harvested rainwater was collected from multiple rain events and analyzed for the following parameters: pH, conductivity, turbidity, total suspended solids, fecal and total coliform, nitrate, nitrite, total and dissolved organic carbon (TOC and DOC), selected synthetic organic compounds, and metals.Three-quarter-inch diameter PVC pipe was used to direct the collected rainwater from the sampling insert to a passive collection system that consisted of a 2-L tank to collect the “first flush” and two 10-L tanks in series to collect samples after the first flush Three-quarter-inch diameter PVC pipe was used to direct the collected rainwater from the sampling insert to a passive collection system that consisted of a 2-L tank to collect the “first flush” and two 10-L tanks in series to collect samples after the first flush Three-quarter-inch diameter PVC pipe was used to direct the collected rainwater from the sampling insert to a passive collection system that consisted of a 2-L tank to collect the “first flush” and two 10-L tanks in series to collect samples after the first flush Hidden text: The abstract may be included at the discretion of the supervisor.

 

BIO

Mary Jo Kirisits is an assistant professor in the Department of Civil, Architectural, and Environmental Engineering at The University of Texas (UT) at Austin.  She completed her BS degree in Civil Engineering at the State University of New York at Buffalo and her MS and PhD degrees in Environmental Engineering at the University of Illinois at Urbana-Champaign.  After concluding a postdoctoral appointment at Northwestern University in the Department of Civil and Environmental Engineering, she joined the faculty at UT in 2004.  Her research interests include various aspects of the presence and activity of microorganisms in natural and engineered systems; she is particularly interested in microbial transformations of inorganic compounds in water, the microbial quality of harvested rainwater, and the effect of nanomaterials on microorganisms in engineered water systems.

 

 

 

 

Three-dimensional dispersion of river gravels

 

Judy Haschenburger

 

Department of Geological Sciences

The University of Texas at San Antonio

 

(Feb 12, 2010, UTSA ESE Graduate Seminar)

 

In gravel-bed rivers grain size selective dispersion of sediment is a fundamental aspect of sediment transport. Size selective transport leads to characteristic patterns in streambed sediments and exerts control over the quality of freshwater habitat.  The purpose of this talk is to present a preliminary analysis of the three-dimensional dispersion of river gravels using observations from one of the longest running field experiments on gravel kinematics in the world. 

 

Empirical observations come from Carnation Creek, a small gravel-bed river located on the west coast of Vancouver Island, British Columbia.  Over 2500 magnetically tagged clasts, ranging in size from 16 to 180 mm, were deployed on the streambed surface between 1989 and 1992.  The analysis presented is based on 11 recoveries of these tracers completed between 1990 and 2008.  During this period over 250 floods capable of moving bed sediment occurred.

 

Results suggest that streamwise dispersion of sediment remains relatively consistent across different grain sizes, crosswise dispersion is relatively constrained in spatial extent, and vertical dispersion into the bed is limited to two times the diameter of coarse grains.  Collectively these results confirm key aspects of the concept of partial sediment transport.

 

 

BIO

Judy Haschenburger is an associate professor at the University of Texas at San Antonio (UTSA).  Prior to her appointment at UTSA in 2005 she held a National Research Council Postdoctoral Research Associateship at the U.S. Geological Survey and a faculty position at the University of Auckland, New Zealand.  Her educational qualifications were earned at the University of Nebraska at Kearney, Arizona State University, and the University of British Columbia, Canada.

 

Her research interests are sediment transport in gravel-bed rivers and related field and quantitative methodologies. Current research projects focus on (1) understanding and modeling the three-dimensional dispersion of sediment over long flood series, (2) defining stable areas of streambeds that serve as long-term refugia for stream biota, (3) modeling sediment transport processes for prescribed instream flows, and (4) articulating the spatial structure and magnitude of sediment exchanges between the channel and floodplain in braided rivers. Her research has been published in the top international scientific journals in her field (e.g., Earth Surface Processes and Landforms, Geomorphology, Journal of Sedimentary Research, and Water Resources Research).

 

 

 

 

 

Findings from the International Flash Flood Laboratory's (IFFL) Inaugural Workshop

Pamela S. Showalter, Ph.D.

Department of Geography

Texas State University-San Marcos

 

(Feb 19, 2010, UTSA ESE Graduate Seminar)

 

On October 19, 2009, a workshop was convened at Texas State University-San Marcos, which is located in the midst of Texas' notorious "flash flood alley". The new International Flash Flood Laboratory, recently established under the auspices of the James and Marilyn Lovell Center for Environmental Geography and Hazards Research, sought "grassroots" guidance to help the new lab determine what critical priorities should be immediately addressed. The day-long affair, attended by members of the public, academia, volunteer organizations, the media, and all levels of government, yielded many suggestions from a variety of perspectives. Ultimately, the participants agreed that there is a critical need for more "Data/Research/Education" in order to adequately address problems associated with flash flooding. Current issues with flash flood "data/research/education" efforts and workshop participants' suggestions for mitigating those issues will be described.

 

BIO

Pamela Sands Showalter is co-Director of the International Flash Flood Laboratory, past-Director of the James and Marilyn Lovell Center for Environmental Geography and Hazards Research, and a Research Associate Professor in the Department of Geography at Texas State University-San Marcos. She obtained her PhD in Geography from the University of Colorado-Boulder, her MA in Anthropology from Arizona State University (Tempe), and her BA in English from Vanderbilt University (Nashville). A long-time hazards researcher, her technical area of expertise lies in digital image analysis; she and colleague Yongmei Lu have just published, "Geospatial Techniques in Urban Hazard and Disaster Analysis" (Springer).

 

 

 

Observing an Artic in transition: Changes in the Arctic cryosphere and impacts on climate, ecosystems, and people

 

Walt Meier, PhD.

 

Research Scientist

National Snow and Ice Data Center, U of Colorado

 

(Feb 26, 2010, UTSA ESE Graduate Seminar)

 

The Arctic is the canary in the coal mine of global climate change. Sea ice extent has been declining over the past three decades and the decline has accelerated in recent years. This decline has been continuously and consistently tracked for over thirty years by space-borne passive microwave sensors - one of the longest satellite data records available. More recent satellite sensors indicate that not only is the areal extent decreasing, but the ice is thinning substantially. The decline of the sea ice cover, particularly during summer, is already having significant impacts on Arctic climate, ecosystems, and human society. Other aspects of the Arctic cryosphere are also showing substantial changes: Greenland is losing mass at an accelerating rate, glaciers are receding, and permafrost is beginning to thaw. The changes in the Arctic will have global impacts, from sea level rise to positive feedbacks amplifying greenhouse gas warming. The National Snow and Ice Data Center (NSIDC) is one of the primary archive centers for cryospheric data and home to several research scientists. A brief overview of NSIDC will be presented at the beginning of the talk.

 

BIO

Walt Meier is a research scientist at the National Snow and Ice Data Center (NSIDC), part of the University of Colorado Boulder’s Cooperative Institute for Research in Environmental Sciences. His research focuses on studying the changing sea ice cover using satellite sensors and investigation of impacts of the declining Arctic sea ice on climate and people. In addition to his research activities Walt is the science lead for sea ice data archived at NSIDC and has also been involved with several outreach and educational activities. From 2001 to 2003 he was an adjunct assistant professor at the U.S. Naval Academy in Annapolis, MD, teaching remote sensing and polar science courses. From 1999 to 2001 he was a visiting scientist at the U.S. National Ice Center in Suitland, MD. He has a B.S. from the University of Michigan (1991), and a M.S. (1992) and Ph.D. in atmospheric and oceanic sciences (1998) from the University of Colorado.

 

 

 

Understanding the impact of surface melt on ice flow in Greenland: the kitchen sink approach

Ginny Catania, PhD.

 

Research Associate at Institute of Geophysics

Assistant Professor at Department of Geological Sciences

University of Texas at Austin

 

(Mar 5, 2010, UTSA ESE Graduate Seminar)

 

Understanding the causes and rates of Greenland Ice Sheet disintegration continues to be an area of active research, motivated by the need to improve estimates of the contribution of the ice sheet to sea level rise. This field of study has included observations of thinning in marginal regions, concern over changes in fast-flowing outlet glaciers, and the debated possibility that the Greenland Ice Sheet could retreat more rapidly than expected due to extensive surface melting. Improved understanding of such processes will have an important influence over our ability to accurately predict future changes in mass balance of the ice sheet. This talk will discuss observations from ground-based ice-penetrating radar and continuous GPS show that surface water enters the ice sheet in discreet locations where conditions allow moulins to form. Moulins appear to be persistent for several years but only a few appear to be capable of draining significant volumes of surface meltwater. Model results (both analogue and numerical) indicate that the influence of draining lakes may be spatially limited.

 

BIO

I got my PhD in Geophsics, at U of Washington, 2004, MS in Geology at U of Minnesota, 1998, and BS in Geolophy at U of Western Ontario, 1994.

My research involves understanding ice sheet and glacier changes both from natural variability and climate forced variability. This involves improving the observational data sets that quantify cyrosphere change but I am also very interested in an improved understanding of the dynamical processes that control ice flow. In particular, my research focuses on basal processes, the flow of water through and beneath ice and grounding line fluctuations.

The main research tools that I use are ice-penetrating radar to image internal layers in the ice and quantify the properties of the basal interface. Simple kinematic models aid in interpretation of internal layer stratigraphy. I also use other instrumentation (GPS, seismic instruments) to understand ice flow. I am particularly enthusiastic about using physical models to reproduce ice dynamical processes. All of these methods are improved through collaboration with ice-sheet modelers (a unique individual adept at simplifying complex problems!) and I attempt to verify each aspect of my work with models in some way.

 

 

 

Groundwater-surface water interactions in ‘natural’ and regulated rivers

M. Bayani Cardenas

Assistant Professor at Department of Geological Sciences

University of Texas at Austin

 

(Mar 12, 2010, UTSA ESE Graduate Seminar)

Processes occurring along the interface between streams and groundwater are key components of stream, hyporheic zone, riparian zone, and aquifer physical and biogeochemical functioning. Most previous studies of stream-groundwater interaction (SGWI) investigated steady-state or quasi-steady state regimes while few analyzed the effects of seasonal perturbation but with synoptic static measurements. In this talk, we present cases where regular and short-term river stage fluctuations profoundly impact SGWI, as well as a case where it does not. At the first study site on the Colorado River, 10 miles downstream of Austin TX, river stage regularly fluctuates by more than a meter within a 24-hour cycle due to hydroelectric dam releases. This causes the river, which receives regional baseflow, to transition between strongly gaining and strongly losing within the same day. We monitored water table elevation, temperature (T), and electrical conductivity (EC) in the riparian zone and in an island. We profiled head, T, and EC vertically along a lateral transect of the streambed during several cycles. The results show rapid pumping of water in and out of the island, the sub-channel hyporheic zone, and the riparian zone. A cubic meter of water goes in and out of the riparian zone per square meter of bank per day. At one location, the vertical upwards fluxes along the streambed range from 5 m/d to -4.5 m/d over one dam-release cycle. About 5,000 cubic meters of groundwater move in and out of the island during the same cycle. This rapid movement of water is consistent with pronounced changes in T and EC in these zones. At this site, natural SGWIs and any related ecosystem services have been drastically altered. On the other hand, observations from a dense network of piezometer clusters within a pointbar of an experimental meandering river indicate uniformity of hyporheic flowpaths across a flood cycle.

The physical processes we investigated exert first-order control on ecological and biogeochemical processes. The coupled mechanical and biogeochemical effects of persistent periodic SGWI should be a focus of future research as more than half of major rivers are dammed and all experience natural processes (e.g., ET and snowmelt) that may induce regular fluctuations in stage and discharge.

 

BIO

 

He got his BS in 1999 from University of Philippines-Diliman, MS in 2002 from University of Nebraska-Lincoln, and PhD 2006 from New Mexico Tech. His research interest is Physical hydrology: groundwater and surface water hydrodynamics, permeability structure of fluvial deposits/ aquifers, applied hydrogeophysics, flow and transport modeling, rivers. Since joined UT in 2006, he received over $2M research funding from various agencies and published over 30 peer-reviewed journal papers. The most recent and distinguished award is the NSF CAREER award $570K (2010-2014).

 

 

 

 

Evaluation of the effluent from compost used for sedimentation control

 

Carlton Ho, Ph.D., P.E.

 

Civil & Environmental Engineering

University of Massachusetts (UMass)

 

(Mar 26, 2010, UTSA ESE Graduate Seminar)

 

The importance of minimizing detrimental impacts of sedimentation at construction sites has been considered a pressing issue for decades. The latest techniques in conventional sedimentation control near wetlands utilize hay bales and silt fences. Although these conventional methods may reduce the amount of sedimentation, their effectiveness is infrequently reliable. These methods, however, are considered the best practices of sedimentation control in Massachusetts. Research from other states demonstrates an increasing interest in the use of compost for sedimentation control. The purpose of this research is to determine the environmental acceptability of wood wastes and composted materials from various sources throughout Massachusetts to control erosion by evaluating the nutrients, chemical content, pathogenic content and toxicity of the effluent.

 

BIO

Dr. Ho has a Bachelor of Science, Master of Science and Doctor of Philosophy in Civil Engineering from Stanford University. He has been on the Faculty of the University of Massachusetts (UMass) since 1996 and is currently Associate Professor of Civil & Environmental Engineering. Prior to coming to UMass, he was a faculty member at Washington State University and the Illinois Institute of Technology. Dr. Ho was also a visiting researcher at the United States Geologic Survey, Menlo Park, California, and the École Nationale des Ponts et Chaussées in Paris, France.

Dr. Ho’s research interests are in the area of geotechnical engineering with experience in earthquake engineering, hazard and risk assessment, slope stability, rheological modeling, earth retaining structures, railroad geotechnical engineering, and geo-environmental engineering.  His research includes field work, laboratory experimentation and numerical analysis. Dr. Ho conducted research in collaboration with the Korean Institute of Construction Technology, and the United States Geologic Survey. His research projects have been funded or supported by the National Science Foundation, the United States Geologic Survey, the Federal Highways Administration, the Federal Railroad Administration, the Transportation Technology Center, Inc. of the Association of American Railroads, Centre National de la Recherche Scientifique (France), Washington State Department of Transportation, the New England Transportation Consortium, the Massachusetts Highway Department.

Dr. Ho is a member of the GeoInstitute of the American Society of Civil Engineers having served as member of the Engineering Geology and Site Characterization Committee (chair), the Earth Retention Systems Committee, the Committee on Soil Scour and Erosion. He currently serves as chair of the Committee on Continuing Education. He has also served on the National Academy of Sciences Transportation Research Board Committee on Engineering Geology, Committee on Soil and Rock Properties, the Subcommittee on Bridge Scour and Erosion and currently serves on the Railroad Track Structure System Design Committee and the Railway Maintenance Committee.

 

 

 

 

Evaluation and application of remote sensing products for improved water resource management

 

John D. Bolten, Ph.D.

 

Hydrological Sciences Branch

NASA Goddard Space Flight Center, Beltsville, MD

 

(Apr 2, 2010, UTSA ESE Graduate Seminar)

 

The role of near-surface moisture dynamics in the hydrologic cycle and their influence on land-atmosphere interaction is well established. Whereas in-situ measurements of soil moisture and other hydrologic variables are accurate, achieving timely accurate regional estimates derived solely from point measurements is difficult because of the dependence upon the density of the gauge network and the proper upkeep of these instruments. Fortunately, recent advances in remote sensing technology have led to improved methods for observing regional and global soil moisture dynamics and other hydrologic states and fluxes. These advances allow us to extend existing hydrological and climate modeling capabilities to further advance hydrometeorological state estimation. From these improved states, we are able to observe, forecast, and apply these measurements in a water management strategies with increased confidence. This presentation will discuss lessons learned, current challenges, and recent applications of airborne- and satellite-based remote sensing instruments for water management. An evaluation of the influence of microwave frequency, spatial/temporal resolution, and land cover type on retrieval performance will be discussed, as well as case studies of assimilation strategies applied towards global agricultural monitoring and regional trans-boundary water management.

 

BIO

 

Dr. Bolten received the M.S. and Ph.D. degrees in geological science with an emphasis in remote sensing from the University of South Carolina, Columbia in 2001 and 2005, respectively, and the B.S. degree in geological science from West Virginia University in 1998. Following a postdoctoral appointment at the USDA Hydrology and Remote Sensing Lab in Beltsville, MD, he joined the Hydrological Sciences Branch, NASA Goddard Space Flight Center in Beltsville, MD in 2008. His primary interests are the utilization of microwave remote sensing in land surface modeling and data assimilation systems for water resource management applications.

 

 

 

 

 

From the tropics to the pole-mapping of snow and glaciers from satellite

 

Andrew Klein, Ph.D.

 

Department of Geography

Texas A&M University, College Station, Texas

 

(Apr 9, 2010, UTSA ESE Graduate Seminar)

 

Optical remote sensing images have long been used to study the Earth’s cryosphere. In fact, the longest environmental time series developed from satellite observations is Northern Hemisphere Snow Cover Extent which begins in 1966. This talk examines applications of satellite images to map snow and glaciers. The talk first examines the physical properties of snow in the optical wavelengths (400 to 2500 nm) that enable snow to be effectively discriminated from other land surface types. The mapping of snow extent and snow albedo from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) is presented to demonstrate how algorithms can be developed to map snow properties from satellite images. The use of satellites to map the retreat of glaciers in two regions of the tropics – West Papua, Indonesia, and the Rwenzori Mountains of Uganda – are used to highlight the both the promise and pitfalls of using satellites to map glacier retreat.

 

 

BIO

 

Dr. Klein's current research interests lie in the application of remote sensing and geographic information science (GIScience) techniques to study the cryosphere. He and his students are currently using remote sensing to monitor tropical glacier recession and he has been actively involved in the development of algorithms to measure snow extent and snow albedo from data collected by NASA's MODIS instrument. He also uses GIScience techniques to study human impacts in Antarctica. For the past seven years he has been involved in a long-term environmental monitoring program at McMurdo Station, Antarctica. Dr. Klein also has an interest in how remote sensing/GIS can aid in improving geographic education and has been working with teachers on a number of educational projects. Dr. Klein is currently an associate professor in Department of Geography at Texas A&M University. He got his PhD in Cornell University in 1997.

 

 

 

 

 

Uncertainty quantification and parameter estimation in subsurface hydrology

 

Alex Sun, Ph.D.

 

Geosciences and Engineering Division

Southwest Research Institute, San Antonio, Texas

 

(Apr 16, 2010, UTSA ESE Graduate Seminar)

 

Subsurface models are critical decision support tools in petroleum engineering, environmental remediation, and water resources management. However, limitations in site conceptualization and geologic characterization can adversely affect the reliability of subsurface models. There is a strong need for continuously improving subsurface models through data fusion and uncertainty reduction. In the last three decades, various stochastic methods have been proposed to quantify and propagate uncertainty in subsurface models. A common component of these methods is the derivation of prior probability distribution functions (PDF) for model parameters and model state variables. Derivation and manipulation of PDFs are challenging from a practical perspective and constitute the biggest obstacle for real application of stochastic methods. Robust optimization, on the other hand, only requires the knowledge of the upper and lower bounds on the uncertainty variables and the feasible solution is guaranteed to be robust against the worst case scenario. Thus, robust optimization can be a useful tool for here-and-now decision making. In this talk, I will demonstrate how uncertainty quantification can be used to link satellite data and in situ measurements to quantify the storage parameters for the Edward-Trinity Plateau aquifer in west central Texas. 

Disclaimer: Any opinions, findings, and conclusions or recommendations expressed in this presentation are those of the author and do not necessarily reflect the views of the Southwest Research Institute®.

 

BIO

 

Dr. Sun, principal research engineer, is a hydrogeologist with expertise in forward and inverse modeling of complex processes in environmental science.  He has training and expertise in environmental water resources, geostatistics, and applied mathematics.  Dr. Sun uses this experience to evaluate risks associated with flow and mass transport processes in heterogeneous porous media, conduct environmental remediation site characterization and feasibility studies, design cost-effective environmental monitoring networks, identify system parameters using deterministic and statistical methods, identify contaminant source release histories, and reduce model uncertainty through continuous data assimilation. Education: Ph.D., Civil and Environmental Engineering, University of California, Berkeley, M.S., Civil and Environmental Engineering, University of California, Berkeley, B.S., Civil Engineering, University of California, Los Angeles

 

PROFESSIONAL CHRONOLOGY:  Los Alamos National Laboratory: research fellow, 1998–9; Tetra Tech Inc.: environmental engineer, 1999–2000; Onward Inc.: software consultant, 2000–3; SUNDA Environmental Technology: part-time consultant, 2001–3; Southwest Research Institute: 2003– [research engineer, 2003–6; senior research engineer, 2006–9; principal research engineer 2009–present].

 

 

 

 

Satellite precipitation retrieval and applications for surface hydrology at global and regional scales

 

Yang Hong (yanghong@ou.edu and http://hydro.ou.edu)

 

School of Civil Engineering and Environmental Sciences, University of Oklahoma

Center for Natural Hazard and Disaster Research, National Weather Center, Norman, OK 73072

 

(Apr 23, 2010, UTSA ESE Graduate Seminar)

 

Better understanding of the spatial and temporal distribution of precipitation is critical to climatic, hydrologic, and ecological applications. Recent development of satellite remote sensing techniques provides a unique opportunity for better observation of precipitation for regions where ground measurement is limited. We will first review the progress of satellite-based precipitation retrieval algorithms and products available for user community.  Then we will discuss applications of the multi-satellite precipitation products at global (http://trmm.gsfc.nasa.gov ) and regional (SERVIR-Africa: http://www.servir.net ) for disasters (flood/landslide) prediction and decision-making support through a new “state-of-the art” global hydrological model.

 

 

BIO

 

Dr. Yang Hong received the B.S. and M.S. degrees in environmental sciences from Beijing (Peking) University, China in 1996 and 1999, respectively, and the Ph.D. degree in Hydrology and Water Resources with emphasis in remote sensing and spatial analysis from the University of Arizona in 2003. Following a postdoctoral appointment at the Center for Hydrmeteorology and Remote Sensing in University of California, Irvine, CA, he joined the Mesoscale Atmospheric Sciences Branch, NASA Goddard Space Flight Center in 2005. Dr. Hong is currently an associate professor in School of Civil Engineering and Environmental Sciences at University of Oklahoma. His primary research interests are remote sensing precipitation retrieval and validation, hydrologic remote sensing, natural hazard prediction and reduction, land surface modeling and data assimilation systems for water resource planning under changing climate.