1. Assessing Environmental Streamflow Characteristics in Texas
Eric S. Hersh
CE394K.3
November 29, 2005
(Wisconsin DNR)

2. environmental flow Definition Flow: the ‘master variable’
water left in or released into a river system
often for managing some aspect of its conditions
Flow: the ‘master variable’
controlling factor in riverine physical, biological, and chemical processes
natural flow regime

3. hydrologic alteration software
USGS
The Nature Conservancy

4. project goals assess models for use in the Texas Instream Flow Program
improve functionality
using the models
producing meaningful results

5. GUI vs. automation HAT: initiated discussion with USGS
possible CRWR partnership
batch processing and/or synthesis with ArcGIS

6. TS Download Tool GIS Tim Whiteaker, CRWR NWIS Peak Streamflow
Parser XML
(Optional)
Raw User
Inputs XML
User Inputs
GIS
Refined User
Inputs XML
Features
Data Retrieval
from Web
Time Series
Table
Time Series XML

7. statewide study
n = 409

8. TWDB priority basins n = 24 Brazos Trinity Sabine San Antonio
Guadalupe

9. major ecoregions

10. normalized median flow

11. normalized median flow interpolation

12. normalized median flow interpolation

13. Kriging prediction error

14. Brazos-Trinity basins interpolation

15. future work HAT automation
dialog with USGS
develop NWIS Peak Streamflow tool
moving toward a Texas stream classification system
analogous to terrestrial ecoregions, but riparian
Principal Component Analysis (PCA) for priority sites and statewide
eliminate redundancy and simplify use

16. data sources daily and peak streamflow data: USGS streams: NHD
via TSDownload Tool
streams: NHD
HUCs: TNRIS

17. acknowledgements
CRWR: David Maidment, Venkatesh Merwade, Tim Whiteaker
TWDB: Jordan Furnans
TCEQ: Wendy Gordon
The Nature Conservancy: Tom Fitzhugh
USGS: Jim Henriksen