1 / 16

Value-Added Attributes for High-Resolution NHD

Value-Added Attributes for High-Resolution NHD. NHD Stewardship Conference March 30, 2012 New Orleans, Louisiana. Josh Lear Nebraska Department of Natural Resources. Goals:. Understand how Value-Added Attributes translate to high resolution NHD Understand Value added attributes

colum
Download Presentation

Value-Added Attributes for High-Resolution NHD

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Value-Added Attributes for High-Resolution NHD NHD Stewardship Conference March 30, 2012 New Orleans, Louisiana Josh Lear Nebraska Department of Natural Resources

  2. Goals: • Understand how Value-Added Attributes translate to high resolution NHD • Understand Value added attributes • How they are derived • How to use them • Find a simple solution to navigating divergences

  3. Agenda • Context for discussion • Preparation and evaluation • Observations • Conclusions

  4. Subregion 1015 - Niobrara

  5. THE NAVIGATION ISSUE GNIS_ID FCode ReachCode Divergence Stream Gage Point of Diversion

  6. Value Added Attributes • FromNode/ToNode • StartFlag/TerminalFlag • VPUin/VPUout • StreamLevel • Divergence • DnDrainCount • Hydrosequence • DnLevel • UpHydroSeq/DnHydroSeq/DnMinorHydroSeq • StreamOrder/StreamCalc • LevelPathID • TerminalPathID • UplevelPathID/DnLevelPathID • PathLength • ArbolateSum • RtnDIV

  7. Navigation Determinants DNR • GNIS_ID • Fcodes • ReachCodes Value-Added Attributes • GNIS_ID • Ftype • LengthKM • + boundary information DNR relationships are local VAA relationships are system-wide

  8. Evaluation • Prepared 1015 using NHDPlus QAQC Tools • 4 Variations based on FlowDirection: • All features “WithDigitized” • Braids “Uninitialized” • Canals “Uninitialized” • Canals and braids “Uninitialized” • VAAs calculated • All Divergences evaluated for downstream navigation

  9. Preliminary Results – (AllFlow) 457 Divergences • 108 failed using the DNR approach (24%) • Not enough information • VAAs always navigated the divergence • Divergent flag • 82 Divergent flags assigned incorrectly

  10. Observations: • Errors still existed in the Flowline • Braids, Field drains • Removing braids improved VAAs • Canals -flow the wrong direction • Canals w/no returns – disconnected drains • Canal w/returns distort the VAAs significantly • Removing canals improved VAAs

  11. Canal – StreamLevel Error

  12. Observations: • Substantial agreement between methods • GNIS_ID • FCodes played a minor role • ReachCode

  13. ReachCode Miss

  14. Preliminary Conclusions: • VAAs are a superior solution • Information is the key • On the flowline • In the VAA program

  15. To Do: • Recalculate and Re-evaluate VAAs for 1015 • Configuration: • Braids, Field Drains, Canals off • Calculate VAAs • Canals on • Look at the other attributes • Catch my flight home

  16. Thanks: • Jeff Simley and USGS • Cindy McKay and Horizon Systems Inc. • NHD Community

More Related