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National Hydrography Dataset (NHD) HIS Symposium March 8

National Hydrography Dataset (NHD) HIS Symposium March 8. Sponsored by US Environmental Protection Agency. Prepared & Presented by Horizon Systems Corporation. Our Agenda. What is NHD? Content Capabilities Status and Data Access What is NHDPlus? Data to Support Analysis & Modeling

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National Hydrography Dataset (NHD) HIS Symposium March 8

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  1. National Hydrography Dataset(NHD)HIS SymposiumMarch 8 Sponsored by US Environmental Protection Agency Prepared & Presented by Horizon Systems Corporation

  2. Our Agenda • What is NHD? • Content • Capabilities • Status and Data Access • What is NHDPlus? • Data to Support Analysis & Modeling • Data Availability • Questions • LDM@Horizon-Systems.Com

  3. 1 2 3 What is the National Hydrography Dataset (NHD)? • A framework dataset that includes: • Hydrographic features for making maps • A national stream addressing system • A modeling network for navigating • upstream/downstream • A maintenance infrastructure • User updates • Distributed format compatible with ArcHydro

  4. What’s in the NHD? • 40+ hydrographic feature types • Permanent “Features” -- Reaches • (Stream Network, Artificial Flow Paths through Waterbodies, Coastlines, Waterbody Areas) • Permanent, Public Ids - Reach Codes • Seamless National Dataset • Multi-Scale – 1:100K, 1:24K, and higher

  5. NHD Comes in Three Sizes • Medium Resolution • 1:100,000 scale • Lower 48 + HI • 2112 Sub-basins • High Resolution • 1:20K, 24K, 63K • 50 States + PR/VI • +/- 1300 Sub-basins • Local Resolution • > High Res • Vermont • ~17 Sub-basins

  6. - Linear Stream Network - Waterbodies - Landmark Features - Feature Names & Attributes Full NHD

  7. - Feature Typing - Basic Attribution - Confluence-to- Confluence Feature Delineation - Topology Dependent - Scale-Dependent Stream Network Full NHD

  8. - Permanent “Features” with Public Identifiers - Scale Independent - Changes Tracked - Hydrologic-based Delineation - Linear Referencing Framework Reaches Stream Network Full NHD

  9. NHD Applications Linear/Areal Referencing Reaches Mapping & Inventory Features Drawing the “Blue Lines” Geometry Modeling & Analysis Network

  10. Stream Network Reaches: The Linear Referencing Framework

  11. Coastlines Connected to the Network Coastline Coastline

  12. Waterbody Reaches: The Area Referencing Framework

  13. 100 • Each linear reach is one addressable unit - a ‘street’ 1 2 100 0 0 • Addresses are proportional ‘street’ numbers 0-100 from bottom to top 100 3 0 Addresses on Linear Reaches

  14. Point Links Linear Links Linear Reach: 02020005000375 Measure: 48.247 Linear Reach: 05030204004722 From Measure: 0.0 To Measure: 100.00 Waterbody Reach: 06030102002785 + shape Area Links Linking Data to the NHD

  15. Navigate with Network Geometry

  16. Drinking Water Intake WQ Monitoring Station Drinking Water Intake Drinking Water Intake 8.7 miles WQ Monitoring Station Timber Production Flow Gage Timber Production State Designated Priority Waters 303(d) TMDL Waters Linear Referencing _______ Upstream & Downstream Analysis

  17. Where to Learn More http://NHD.USGS.GOV

  18. Where to Get the Data http://NHDGEO.USGS.GOV

  19. NHD Medium Resolution Status

  20. NHD High Resolution Status Planned In Work Available

  21. NHD Local Resolution Status

  22. 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

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

  24. 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.

  25. 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

  26. 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 Navigation Analysis Display • Generalization Attribute

  27. 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

  28. Common Problems with Geometric Navigation

  29. Flow Table Network Navigation • Flow relationships between network features “Feature A flows to Feature B” • Can be use totally independent of geometry

  30. 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

  31. VAAs Help with NHD Displays

  32. 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

  33. 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” (NEM) • Outputs include catchments in grid format and as polygons

  34. The NEM Approach • NHD stream network burned into NED • NHD network waterbodies used to bowl the NED • Where available, Certified Watershed Boundaries (HUC10 & 12) used to build walls • Where possible, sinks placed at ends of “true” isolated networks

  35. Catchments

  36. Catchment Validation • Stream Gage drainage area measurements Is the drainage area size correct? • Stream Gage drainage area boundaries Is the drainage area in the correct location?

  37. Catchment Characteristics • Mean Annual Temperature (Prism) • Mean Annual Precipitation (Prism) • % of each Land Use from NLCD

  38. Catchment Process By-Products • Flow Accumulation Grid • Flow Direction Grid • Stream Network Node Elevations

  39. Elevation Smoothing

  40. USGS Flow GagesLinked to NHD • NWIS site location snapped to NHD • USGS WRD district offices reviewed and adjusted, as needed • Revised NHD locations converted to an event table with Reach Code and Measure

  41. Flow EstimatesUnit Runoff Method • Estimate average annual unit runoff by 8-digit HUC (sub-basin) • Apply distance-weighted Average of Annual Unit Runoff for USGS NLCD Gages; simplified “zone of influence” • QA Using USGS runoff isopleth map

  42. Flow EstimatesUnit Runoff Method (cont) • Estimate Drainage Area (DA) for Each NHD segment • Compute incremental segment runoff • Delta Q(cfs) = DA(sq km) * Unit Runoff (cfs/sq km) • Route and accumulate incremental flows to estimate mean annual flow by segment • QA by comparing to USGS gage mean annual flows

  43. Flow EstimatesVogel, et al Method • Flow estimates developed using mean annual flows at HCDN gages • Multiple regression technique with coefficients by hydrologic region • Independent variables: • Cumulative Drainage Area (DA) • Mean annual temperature (MAT), from PRISM • Mean annual precipitation (MAP), from PRISM • Mean Annual Flow = f(DA, MAT, MAP)

  44. Flow EstimatesVogel, et al Method (cont.) • NHD Plus implementation uses catchment-based DA’s, PRISM data overlaid on catchments • Reference: Vogel, R.M., Wilson, I.W., Daly, C. 1999. Regional Regression Models of Annual Streamflow For the United States. Journal of Irrigation and Drainage Engineering.

  45. 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)

  46. 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.

  47. NHD Plus – Components • Greatly improved 100K NHD • Value Added Attributes • Elevation-based Catchment • Catchment Characteristics • Flow Direction and Flow Accumulation Grid • NHD Network Node Elevations • Stream Gages Linked to Stream Network • Flow Volume & Velocity Estimates

  48. “Dynamically” Define Drainage Areas

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