1. NHD Stream Order Possibilities Timothy R. Bondelid Research Triangle Institute Research Triangle Park, North Carolina 27709 (919)485-7797; fax (919)485-7777 e-mail: timothy@rti.org

2. Stream Order 1 1 2 2 11 3 1 3

3. Topics The Three Main Characteristics of NHD (and all Reach Files) Hydrologic Sequencing and Routing Example of NHD Routing, Stream Orders, and Changing Network Density “Hydrologic Equity” Example

4. The Three Main Characteristics A Common Numbering Scheme for All Surface Waters in the System –The Reach Number A Map Representation of the Surface Water Features A Tabular/Database Routing Network

5. Tabular Routing “Engine” for Modeling Invented by Bob Horn, USEPA Retired

6. Stream Level 3 2 2 1 12 1 2 1

7. Hydrologic Sequence 5 4 6 3 12 7 8 9

8. Stream Order 1 1 2 2 11 3 1 3

9. Stream Number 4 3 3 1 15 1 2 1

10. NHD Example of the Tabular Routing for Stream Orders and Density ArcView Presentation

11. “Hydrologic Equity” Define the Network in Terms of Hydrologic Characteristics Example in ArcView (RF3) Using Mean Annual Flow Estimates

12. Summary Stream Orders Can be Made With NHD Stream Orders are “Sensitive” to the Density Issue The NHD is a Very Flexible Network –The Full Richness of the Network Can Be Used for Varying Levels of Analysis, Display, and Modeling

13. Thank You!

14. Water Quality Management and Policy Modeling Tools using the National-Scale Reach File 3 (RF3) Hydrography Network Timothy R. Bondelid, Suzanne J. Unger, Randall C. Dodd, and Dario J. Dal Santo, Research Triangle Institute Research Triangle Park, North Carolina 27709 (919)485-7797; fax (919)485-7777 e-mail: timothy@rti.org; sju@rti.org; rdodd@rti.org; dalsanto@rti.org

15. The National Water Pollution Control Assessment Model (NWPCAM) This Work Has Been Funded by The U.S. Environmental Protection Agency Acknowledgements: –Dr. Mahesh Podar, Dr. John Powers, and Ms. Virginia Kibler in the U.S. EPA Office of Water –Dr. Charles Griffiths in the U.S. EPA National Center for Environmental Economics Significant Others: –C. Robert Horn, Mary Jo Kealy, George Van Houtven, and Tayler Bingham

16. Agenda Overview of Approach Major Challenges Assessment Framework Hydrologic Components Example of Results Conclusions

17. Overview of Approach

18. Major Challenges Need to be Able to Evaluate Large-Scale Changes Due to Pollution Control Policies But: Water Quality is Generally a “Local” Issue Need to Link to Economic Benefits Addressing These Two Challenges Makes the System Unique

19. The 18 Hydrologic Basins

20. The 2100 HUC’s

21. Subset of Reach File Version 1

22. Hydrologic Region 7 with RF1

23. Assessment Framework

24. Reach Files and Modeling Any Reach File Contains Three Elements: –A Standard, Unique Identifier for Each Surface Water Feature in the System –A Digital Map Representation of the Features –A Tabular Routing/Navigation “Engine” that is Powerful and Fast The Reach Files Have Been Used for Modeling Since 1982

25. RF1 In Upper Potomac

26. RF3 in Upper Potomac

27. RF3Lite in Upper Potomac

28. Hydrology: How Much Water? Estimate Average Unit Runoff by HUC Estimate Drainage Area for Each RF3 Reach Route and Accumulate Drainage Areas and Flows Down RF3

29. Average Annual Runoff Use “Hydrologic Centroids” of HUC’s Apply Distance-weighted Average of Annual Unit Runoff for USGS NCD Gages Testing: –HUC-level Unit Runoff –Drainage Areas –Flows

30. USGS Isopleths of Unit Runoff

31. Calculated Unit Runoff By HUC

32. Drainage Areas: Connecting Land Cover Database to RF3 Reaches

33. USGS Drainage Areas Vs. RF3 Drainage Areas

34. USGS Flows Vs. RF3 Flows

35. How Deep, Wide, Fast?

36. Basic Hydraulics Assume Rectangular Channel Manning’s “n” is a Function of “Sinuosity” of the Reach: –Sinuosity is the Reach Length/CFD –CFD = “Crow Fly Distance” –Reach “n” Increases as Sinousity Increases Slopes Derived From RF1/DEM-based Data Channel Widths From RF3 Geometry or Keup-derived Function for single-line streams

37. RF3Lite: Open Water Widths and Sinuosities

38. Channel Widths and Depths Single-Line Stream Widths (Keup): –W = 5.27 * Q 0.459 Double-Wide Channel Widths from RF3 Geometry Depth: Manning’s Formula Assuming a Rectangular Channel –Y 0 = 0.79 * (Q * n /(W * (S 0 ) 0.5 ) 0.6

39. The Whole Process

40. Example: Two Scenarios on a Stretch of River

41. Conclusion: NWPCAM is an Evolving System with Every Component Undergoing Enhancements

42. Thank You!