By Courtney Swyden
Former Rice University civil and environmental engineering graduate student Erin Williford tested various hydrologic models to create a framework for a real-time, radar-based flood alert system for the Onion Creek watershed in Austin, Texas.
“Emergency personnel and citizens can have advanced warning and accurate lead time during a large storm that will hopefully prevent the loss of life or property,” said Williford, a recipient of a $5,000 2004-05 Texas Water Resources Institute research grant.
She began by collecting radar data from the National Weather Service’s Next Generation Radar (NEXRAD). She said the Onion Creek model was calibrated based on numerous historical rainfall events and produced flows consistent with those measured by stream gauges.
“By using radar rainfall data combined with the existing rainfall gauge network, we had a more complete and accurate depiction of storm events,” she said.
To determine peak flows and the approximate time of the peak for Onion Creek, rainfall data was entered into a flood hydrograph package, HEC-1, which converts the rainfall data to runoff. HEC-1 was developed by the Hydrologic Engineering Center and it allows for fast computation results of peak flows available every five to six minutes.
Geographic information systems (GIS) technology will be used to separate sub-areas in the creek and develop watershed characteristic data. GIS technology is an environmental modeling system that uses satellites to map many types of geologic features.
Since peak flows are predicted using these technologies, the Onion Creek flood alert system will provide increased lead time and accurate flow levels to the city. City officials and emergency personal can be alerted in advance and put precautionary flood measures into effect, she said.
“Flood prediction is unique in that it can impact people’s lives and properties. It is good to know that there are tools available to predict flooding,” said Williford.
Williford, originally from Sugar Land, Texas, received her bachelor’s degree in meteorology at Texas A&M University and her masters from Rice. She is currently working for Turner Collie & Braden, Inc., an engineering company, in Houston. She works on various water resource projects for municipalities and various private facilities.
Her research was funded by TWRI through the U.S. Geological Survey as part of the National Institutes for Water Research annual research program. TWRI is the designated institute for water resources research for Texas.
For more information on Williford’s research, visit USGS Research Grants.
