wyoming’s nhd and wbd maintenance and enhancements nhd/wbd stewardship conference march 29-30,...
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Wyoming’s NHD and WBD Maintenance and Enhancements
NHD/WBD Stewardship ConferenceMarch 29-30, 2012New Orleans, Louisiana
Paul CaffreyWyoming Geographic Information Science Center(WyGISC)
Overview
What have we done
What have we not done
What next
Discussion/Questions
State Events
Dams
Gaging stations
Diversion structures
State Dam/Gaging Station/Diversion Structure
1,458 new Dam Events were added that were not
originally captured in NHD
56 existing Dam Events were spatially corrected
(these dams were originally captured in NHD, but
not at correct location/point along NHD Flowline)
90 new Gaging Station Events were added
24 new Diversion Structure Events with radio
telemetry
GNIS & NHD
Performed a check to locate and correct
1. Missing
2. Misspelled
3. Misplaced
named features for the streams, rivers, lakes and point features in Wyoming
GNIS & Hydrographic Features
GNIS & Hydrographic Features
GNIS & NHDFor the NHD, the task for assigning names to water features using the GNIS was a pretty straightforward process. Unfortunately, discrepancies and errors persist due to:
low resolution GNIS vectors and points and coordinate errors
interpretative mistakes made during GNIS conflation process while creating the hydrographic data.
Example: GNIS line vectors
GNIS updates made to Wyoming’s NHD
Streams:
97 NHD Flowlines (originally unnamed) received
GNIS names and ID numbers
129 NHD Flowlines received corrections to their
GNIS name and/or ID number
19 are unable to be corrected due to inherent GNIS
coordinate errors and other issues
Lakes/Reservoirs:
638 NHD unnamed Waterbodies received GNIS names
and ID numbers
118 NHD Waterbodies received corrections to their
GNIS name and/or ID number
123 WB features missing geometry have been
captured
Lakes/Reservoirs (cont.):
34 NHD Waterbodies with missing or incorrect
GNIS names/IDs are still in need of correction
294 are unable to be corrected due to inherent GNIS
coordinate errors and other issues
Springs/Waterfalls/Rapids:
• 206 missing features currently being captured, soon
to be added to NHD Point geometry
• 236 NHD Points with missing or incorrect GNIS
names/IDs in need of correction
• 62 not corrected due to inherent GNIS coordinate
errors
WBD- Hydrologic Unit Name Updates 151 watersheds (10-digit units) have received an
updated HU_10_NAME 52 of these are shared with one or more bordering states and are
awaiting coordination
1,309 subwatersheds (12-digit units) have received
an updated HU_12_NAME 153 of these are shared with one or more bordering states and
are awaiting coordination
NHD/WBD Pour Points
NHD/WBD Pour PointsPrimary purpose for creating the True Pour Point features was twofold: 1) To capture the most accurate geographic location of
all WBD outlets/stream drainage points using the 2009 NAIP
2) To assess the horizontal accuracy and vertical alignment discrepancies between a stream's current pour point location and its WBD and NHD counterpart• Pour Point/NHD average offset distance
equaling ~70 meters• Pour Point/WBD average offset distance
equaling ~121 meters.
NHD/WBD Pour Points 2,327 True Pour Points were placed at the most
horizontally accurate/current geographic location of
drainage points for all streams at WBD outlets
The number of True Pour Points exceed the
number of WBD outlets (2,195), due to multiple
drainage points from complex stream channels
2,192 NHD Pour Point Events were indexed to the
top of all NHDFlowline reaches draining from WBD
outlets
NHD/WBD Pour Points
Acknowledgements-USGS/NRCS
NHD/WBD Team
Barb Ray, WY Geo-Liaison
Wyoming BLM:
State Office, Rick Schuler
Wyoming State Engineers Office
Jason Feltner
Wyoming Board of Geographic Names
UW/WyGISC Team
Pat Madsen, GIS Specialist
Discussion
Questions