1. Flood Analysis of Scioto River Using HEC-RAS/GIS Converting HEC-2 Data for HEC-RAS /ArcView GIS Analysis and Inundation Mapping (A pilot using Big Darby Creek )

2. 1873 flood of Athens No Exact Record Available

3. 1907 flood - the highest known flood The estimated peak discharge was 50,000 cfs

4. The Joseph Herrold Home Before and After the 1913 Flood Before...

5. Joseph Herrold home after the flood of 1913

6. Flood on March 11, 1964 - Ohio University, Athens A height of 24.18 feet was recorded on the gage station

7. Pre-processing USGS 1:24,000 DLGs AVRas Pre-processing Function –TIN creation (temporary from DLGs) –Preparing required themes in ArcView GIS Bank lines Center line - require a line between banks Flow lines - direction of the flow –X-sections digitized from surveying maps

8. Pre-processing (cont.) Digitizing provided X-sections using Arc/Info Conversion to ArcView GIS Labeling stations for X-sections

9. Pre-processing Creating the HEC-RAS import file (*.geo) using AVRas –Temporary TIN –Center line –Bank lines –Flow lines –X-Sections

10. HEC-2 X-sectionsPreprocessed X-sections

11. Geo-referenced X-sections

12. Importing GIS and HEC-2 Data Separately import GIS geometry file (*.geo) and HEC-2 data Adjust GIS geometry file according to HEC-2 data –Ground elevations –X-section lengths Run an Avenue script to export X-sections into ArcView GIS –Program written by Nan Shi –Generate two shapefiles - X-sections and elevation points Adjust new X-sections referencing streams in GIS

13. Cross-Section Cleaning Cross-sections lengths adjusted by HEC-2 data Position verified by USGS data Flow length verified by HEC-2 data Digitized Adjusted

14. Final DEM Production Point elevation data (original HEC-2 data) Topographical elevation data (USGS data) New TIN created for flood plain delineation New DEM

15. HEC-RAS Adding parameters –Manning’s‘n’ values –Ineffective flow areas –Bridges –Steady flow data Run water surface profile computations Model verification

16. Model Verification Original HEC-2 New HEC-RAS

17. Post-processing HEC-RAS export file AVRas post-processing Flood plain for 4 profiles –17,800 cfs –30,800 cfs –38,000 cfs –58,000 cfs

18. Big Darby Flood Delineation 17,800 cfs - green 30,800 cfs - red 38,000 cfs - blue 58,000 cfs - purple

19. Adding Additional Geographic Information 17,800 cfs

20. Adding Additional Geographic Information 30,800 cfs

21. Adding Additional Geographic Information 38,000 cfs

22. Adding Additional Geographic Information 58,000 cfs