NHDPlus: A Big PLUS for User Applications ESRI User Conference - July 24, 2005 The NHDPlus Team

1. NHDPlus: A Big PLUS for User ApplicationsESRI User Conference - July 24, 2005The NHDPlus Team Horizon Systems Corporation Sponsored by US EPA

2. The NHDPlus Team EPA Project Lead Tommy Dewald Horizon Systems Cindy McKay Jen Hill Bob Deffenbaugh USGS WRD Rich Moore Craig Johnston Al Rea RTI International. Tim Bondelid

3. NHD Plus – What is it? • Greatly Improved 1:100K NHD • A Set of Value Added Attributes • Elevation-based Catchment for Each Segment in the Stream Network • Catchment Characteristics • Flow Direction and Flow Accumulation Grids • NHD Network Node Elevations • Stream Gages Linked to Stream Network • Flow Volume & Velocity Estimates for Each Segment in the Stream Network

4. 1:100K NHD Improvements • Stream and waterbody name corrections and additions • Correction to stream network coordinate order (pointing downstream) • Correction of gaps, overlaps, overshoots, etc. in network geometry • Independent QAQC of flow table. • Flow table and geometry agree.

5. The Value-Added Attributes: • A set of two dozen network characteristics • Based solely on native NHD content • Created with software • Built using the national NHD • Provides alternatives to navigating with the geometry

6. Value Added Attributes • Drain Stream Level • Link-Node Traversal • Hydrologic Sequence • Terminal Identifiers • Level Path Identifiers • Independent Flow • Table • Stream Order • Waterbody Identifier • Waterbody Type • Upstream Miles • Distance to Sink • Stream Order • Waterbody Identifier • Waterbody Type • Upstream Miles • Distance to Sink Navigation Analysis Display • Generalization Attribute

7. Simple Query Network Navigation • A Series of Attributes Computed From the Flow Table and the Geometry • Once Computed, Independent of Geometry and GIS • Navigate with SQL Query

8. VAAs Help with NHD Displays

9. VAAs for Analysis e.g. Strahler Stream Order The smallest permanent streams are called "first order". Two first order streams join to form a larger, second order stream; two second order streams join to form a third order, and so on. Smaller streams entering a higher-ordered stream do not change its order number. Strahler 1964 1 1 2 1 1 2 1 2 3

10. Catchments • The portion of the land surface that drains to a network segment • Catchments built using 30m National Elevation Dataset (NED) • Generated using the “New England Method” (with AGREE.AML) • Outputs include catchments in grid format and as polygons

11. NHDPlus Catchments

12. NHDPlus Catchments Production status 7/8/05 – 2,161,911 catchments and counting

13. International Catchment Areas

14. Bathymetric Gradient in Waterbodies

15. Standard DEM Flow lines

16. Flow lines with Bathymetric Gradient

17. Elevation SmoothingPerform and display analyses along a stream profile

18. Flow EstimatesUnit Runoff Method • Estimate average annual unit runoff by 8-digit HUC (sub-basin) • Estimate Drainage Area (DA) for Each NHD segment • Route and accumulate incremental flows to estimate mean annual flow by segment

19. Flow EstimatesVogel, et al Method • Flow estimates developed using mean annual flows at HCDN gages • Multiple regression technique with coefficients by hydrologic region • NHD Plus implementation uses catchment-based DA’s, PRISM data overlaid on catchments

20. Cumulative Drainage Area Snake River

21. Flow Estimates Vs Gage Flow 50000 45000 40000 35000 30000 qurom NHD Flow (cfs) 25000 qvogel 20000 15000 10000 5000 0 0 5000 10000 15000 20000 25000 30000 35000 40000 45000 50000 Gage Flow (cfs)

22. Velocity Estimates • Inputs: Drainage area, stream segment slope, mean annual discharge • Future QAQC Possibilities: USGS Time of Travel Database • Reference: Jobson, H. E. 1996. Prediction of Travel Time and Longitudinal Dispersion in Rivers and Streams. USGS Water Resources Investigations Report 96-4013.

23. NHDPlus Applications - Some Examples • Some of these are “Right out of the box” • Some are simple ArcView Operations • Some require programming • Within a database environment • The programming is not complex or lengthy • Analyses can go back and forth between catchments and the flow network • For many applications, building the front end user interface is probably more work than the actual application building

24. Quad Density Artifacts in NHD

25. NHD with Flow > 2 cfs: Hydrologic Equity

26. Cincinnati “Area of Influence”: The Watershed that is 3 Days Time of Travel Upstream

27. Simple Dilution and Decay Model

28. SPARROW Model Results: Predicted Total Nitrogen Catchment Yield Contributions to Total Nitrogen from each source + = Atmospheric Developed + + Agriculture Point Source

29. Update NHD Location - • Correcting the GeoCoding, use Update NHD Location tool. • Zoom-in to site and NHD reach, DRG highly recommend. • Click Update NHD Location tool, (cursor changes to flag) • Click on NHD stream that best represents where streamflow is being gaged (before) (after) 13082500 13082500

30. Streamgage Review Summary • 23,945 gages were reviewed and examined • 17,482 gages batch indexed correct & NHD location not moved - 73%. • 962 gages were flagged as "Do Not Use“ - 4% • 1230 gages were flagged as "No 100k NHD Reach" - 5% • 4271 NHD locations moved an average of 795 meters - 18% • 4111 site locations moved an average of 1123 meters - 17% • 117 meters is the mean distance between the site location and NHD location

31. Wrapup - Importance of the VAAs • Easier answers to network questions • Fast, simple, reliable network navigation • Fast, sequential routing • Simple SQL queries • Link Node routing • Provide some commonly used attributes • Stream Order • Hydrologic Sequence • Stream Path Identifier • Establish the integrity of the network

32. For More Information: • NHD Sessions I and II Tuesday AMRoom 25-C (SDCC) • NHD User Group Meeting Wed 12:15—1:15 Room 30-B (SDCC)

33. Contacts: • Tommy Dewald DEWALD.TOMMY@epamail.epa.gov • Cindy McKay LDM@Horizon-Systems.com • Tim Bondelid timothy@rti.org • Rich Moore rmoore@usgs.gov • Craig Johnston cmjohnst@usgs.gov • Al Rea ahrea@usgs.gov

34. NHDPlus Production Units 20 (Targeted Completion Dec, 2005)