1. Space-Time in Hydrology How to define the GIS of the Future?
David R. Maidment
Center for Research in Water Resources
University of Texas at Austin

2. “What, Where, When” Model
We have a set of variables defined over a domain of space and time
Variables can describe the environment or water moving through the environment
Space can be continuous or discrete, 2D, 3D
GIS Requirements?

3. GIS Describes the Environment
Physical landscape
Political and social dimensions
Land surface terrain
Natural environment
Infrastructure environment
GIS Requirements?

4. A Domain in Space and Time
A particular study occupies a domain in space and time
Space
Field, City, Watershed, Aquifer, Basin, Country, World
Time
Hours, Days, Months, Years, Centuries, Geological
GIS Requirements?

5. How does water flow through the domain?
Atmosphere
Surface
Subsurface
Environment
Natural
Infrastructure
How will flow be changed if environment is altered?
GIS Requirements?

6. Modeling Water Flow and Quality
Traditional role of GIS is a model pre-processor and sometimes post-processor
Componentized models emerging (OpenMI)
Running models on remote servers (“the cloud”)
GIS Requirements?

7. Describing Water Observations
Direct measurement of water properties as point time series
Gages at sites
Water Samples taken to a lab
ADCP and moving boat measurements
Remote sensing
GIS Requirements?

8. Weather and Climate Drivers
Spatially continuous fields of information derived from weather and climate models
Forecasts:
Weather – 3 hour time steps to 5 days out
Climate – monthly time steps to 1 century out
History
Weather over past century
Paleoclimate
GIS Requirements?

9. Some Current Trends Acquiring data as services rather than as files
Rapid expansion of internet bandwidth, computer speed and storage capacity favors centralized solutions
“the cloud”
GIS Requirements?