Welcome

Dr. David R. Maidment, Director
Center for Research in Water Resources
University of Texas at Austin

Each year since 1994, we have presented a GIS Hydro PreConference Seminar at the ESRI User Conference.  Initially, we documented the content and background to this seminar with a workbook distributed at the seminar, then in 1998, we switched to producing a CD-ROM and in 2005, we switched to documenting everything on a seminar web site.   The inventory of these CD-ROMs and web sites from past GIS Hydro seminars beginning in 1998 can be seen at http://www.crwr.utexas.edu/archive.shtml Preparing this information has been a valuable opportunity for our CRWR research team to each year document the latest findings, data and tools from our research program in a form that is accessible and usable by the GIS in Water Resources community.   And so it is again this year.

GIS Hydro 2007 has five sections, the first of which contains the regularly appearing information, and the remainder reporting on new lines of research and development for this year:

  • Introduction —  this section contains this introduction, presentations made at the GIS Hydro ’07 Preconference seminar, the classroom exercises that we used in the 2006 version of our GIS in Water Resources class (for which I thank David Tarboton of Utah State University for his contributions), and the term projects that resulted from this class at UT Austin.
  • Arc Hydro — this section describes the current Arc Hydro data model and tools and provides a link for the latest version of the toolset and supporting documents prepared by ESRI.   Dr Dean Djokic is the leader of the water resources applications group at ESRI and he is presenting this section of the seminar.   In this section there are also materials contributed by Nishesh Mehta of CRWR about NHDPlus, a new version of the National Hydrography Dataset that links stream network reaches with small catchments defined around them from the National Elevation Dataset.  
  • GIS and HIS —  this section derives from our work with the Consortium of Universities for the Advancement of Hydrologic Science, Inc, (CUAHSI), an organization representing 112 US universities which is funded by the National Science Foundation to develop infrastructure and services to support the advancement of hydrologic research and education at US universities.  I am the leader of the CUAHSI Hydrologic Information System project.  This effort is focused on the representation of hydrologic observation data, that is, rainfall, streamflow, water quality, groundwater levels, and climate, using relational databases and web services, in which GIS is used as a map front end to geospatially unify sources of water information for the nation.   This is an exciting and challenging new aspect of the use of GIS in Water Resources, that will advance significantly in future years though a new customization of ArcGIS Server 9.2 called HIS Server that is being worked on by Dean Djokic and his team at ESRI.  I want to acknowledge the contributions to our HIS work of our technology partner, the San Diego Supercomputer Center (Ilya Zaslavsky, David Valentine and Tom Whitenack), and colleagues in other academic institutions (David Tarboton, Jeff Horsburgh and Kim Schreuders from Utah State University, Michael Piasecki and Bora Beran at Drexel University, and Jon Goodall from the University of South Carolina).
  • Space-Time — this section describes our on-going work to add a time dimension to ArcGIS.  In ArcGIS 9.2, ESRI has added support for multidimensional data in netCDF format as a capability in ArcGIS, and has significantly improved the ability to do time series plots and time-space animations in ArcGIS.   Virginia Smith has illustrated these capabilities in these materials.  This will open up a large set of new data sources to ArcGIS users, among which is the DayMet dataset from NCAR and real-time weather data services from Unidata.  Simulation model outputs from the Water Rights Analysis Package (WRAP) are being researched by Clark Siler and Tim Whiteaker to see how to use mapping, animation and graphing in ArcGIS to visualize water supply reliability in Texas river basins.  Ernest To is using 3D kriging to examine the variations of salinity concentration in Corpus Christi Bay. At CRWR, Carlos Patino has built a very large Arc Hydro time series dataset for the Rio Grande basin, currently numbering more than 5 million records.
  • Environmental Flows — this section introduces the work of Eric Hersh who is studying how to estimate the requirements for environmental flows for Texas streams and rivers.  His work integrates hydrology, water quality, geomorphology and biology of streams and rivers.  An additional component of this subject is supplied by Dr Venkatesh Merwade’s work on river channel morphology – Venkatesh is now with the Dept of Civil Engineering at Purdue University.
  • Continental Water Dynamics — this is a new endeavor this year being carried out by PhD student, Cédric David, inspired in part by the NHDPlus dataset.  NHDPlus contains 2.3 million river and water body reaches of average length 2 km, each of which having an associated catchment of area 3 km2.  We start with the question “can we compute the flow of water simultaneously in all the river and water body reaches of the nation”.   We are also inspired by the expansion of “petascale computing” for which our Texas Advanced Computation Center is presently building a supercomputer with 50,000 parallel processors.  In this work, we are collaborating with Dave Gochis at the National Center for Atmospheric Research.
  • Groundwater — this section reports on the evolving development by Dr Gil Strassberg of a groundwater data model for ArcGIS and both a draft geodatabase and toolset for manipulation of groundwater features are included. I would like to acknowledge the contributions of Dr Norman Jones of Brigham Young University, and Steve Grisé of ESRI to this effort.   We are this year holding a separate PreConference Seminar on Groundwater and we are working on a new book on the Arc Hydro Groundwater Data Model.  Dr Jone’s group is going to take over the development of a new toolset for groundwater data analysis in ArcGIS.
  • Water Quality  this section describes the work of PhD student Stephanie Johnson into Total Maximum Daily Load (TMDL) computations for water pollution assessment.   Stephanie has demonstrated that it is possible to use CUAHSI web services to quickly integrate streamflow and pollutant concentrations at sampling sites and thus simplify the development of Load Duration Curves, an important component of TMDL studies.

There are many people whom I'd like to thank for help in producing this CD-ROM.  First among them is Clark Siler, the CRWR graduate student who managed the assembly of the materials on this year's GIS Hydro 07 website.  Other CRWR students and graduates whose work is presented here include Cedric David, Eric Hersh, Stephanie Johnson, Nishesh Mehta, Venkatesh Merwade, Carlos Patino, Virginia Smith, Gil Strassberg, Ernest To, and Tim Whiteaker.   I want also to acknowledge the contribution to the Arc Hydro effort by Dean Djokic, Zichuan Ye, Christine Dartiguenave, Steve Kopp, Clint Brown, Scott Morehouse, Jack Dangermond, and their colleagues at ESRI Redlands, who have been continuously supportive of the advancements we have been making.

I hope you find this information helpful in your work.   If you have any comments or questions, please contact the individuals given in each section of the material or send an enquiry to me directly.

David R. Maidment
Hussein M. Alharthy Centennial Chair in Civil Engineering
Director, Center for Research in Water Resources
The University of Texas at Austin
maidment@mail.utexas.edu
http://www.ce.utexas.edu/prof/maidment/home.html