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

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

hydrologic alteration software USGS The Nature Conservancy

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

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

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

statewide study n = 409

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

major ecoregions

normalized median flow

normalized median flow interpolation

normalized median flow interpolation

Kriging prediction error

Brazos-Trinity basins interpolation

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

data sources daily and peak streamflow data: USGS streams: NHD http://water.usgs.gov/ via TSDownload Tool streams: NHD http://nhd.usgs.gov/ HUCs: TNRIS http://www.tnris.state.tx.us/

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