1. WATERWAYS AND BRIDGES IN TEXAS “Final” Presentation by: Brandon Klenzendorf CE 394K 11-22-05 Dr. Maidment

2. Background ► TxDOT to use crash-tested bridge rails ► May impact FEMA 100-year floodplains ► Cause for map revisions – time and money! ► Need to determine how bridge rails affect water surface profiles

3. TxDOT Design Frequencies TxDOT Hydraulic Design Manual

4. Project Purpose ► In order to solve this problem, we need to predict…  Hydraulic impact of crash-tested bridge rails  100-year peak flood discharges ► Determine peak discharge for 100-year return period flood ► Use GIS and NFF programs to gain info on flood discharges

5. GIS Data Collection ► State of Texas HUCs from TNRIS  http://www.tnris.state.tx.us/ ► Major highway network from TNRIS ► Major stream network from TNRIS ► DEMs for selected bridges from USGS  http://seamless.usgs.gov/

6. 1 2 3 4 5 6 7 8 9 10 11

8. ArcHydro Tools ► DEM processing  Problems with gaps in stream layer ► Drainage line creation ► Batch point watershed delineation ► Longest upstream length ► Upstream and downstream elevations

9. Bridge 1 Problems!

10. USGS NFF Program ► National Flood Frequency Program ► Estimates the magnitude and frequency of flood peak discharges and hydrographs  2, 5, 10, 25, 50, 100, and 500-year frequency floods ► Uses Visual Basic and regression equations specific for each state ► FREE!!! ► http://water.usgs.gov/software/nff.html

11. NFF Program Parameters ► Drainage Area (A) – area (mi 2 ) contributing to flow at the bridge ► Shape Factor (SH) – ratio of stream length squared (mi 2 ) to drainage area (mi 2 )  Represents stream length to average width ► Stream Slope (SL) – change in elevation (ft) divided by steam length (mi)

12. Hydrologic Regions ► Determined based on physiography and climatic conditions ► Each hydrologic region has range of applicable parameters ► Hydrologic Region 1 - Q 100 =371A 0.847 SH -0.307

13. Determined NFF Parameters Hydrologic Region Area (mi 2 ) Upstream Length (mi) Slope(ft/mi) Shape Factor Latitude(DD)Longitude(DD) R-11120.929.129.850.75636.202-101.306 R-2548.417.1637.620.53731.878-103.947 R-33408.145.5313.240.60834.090-99.730 R-42098.040.197.770.77032.399-100.894 R-51447.043.0411.661.28029.514-97.494 R-6489.227.966-98.973 R-71917.433.072-97.532 R-82590.931.435-97.759 R-9571.028.703-97.047 R-10991.232.777-95.798 R-11923.230.396-94.255

14. NFF Interface

15. Flood Region Map

16. NFF Results ► 100-year hydrograph for five bridges ► Bridge 5 has largest peak, but third largest area ► Bridge 3 has second lowest peak, but largest area 1 2 3 4 5

18. Completed Work ► Geodatabase of Texas rivers, highways, and HUCs ► ArcHydro tools for all bridges ► Batch point watershed delineation for all bridges ► Partial completion of longest stream length ► Partial completion of NFF analysis

19. Future Work ► Longest stream lengths for remaining Hydrologic Regions ► NFF analysis for all bridges ► Comparison of results ► Analyze errors in DEMs, HUCs, and bridge locations ► Write final report

20. Questions ?