1. Local Resolution NHD Photo-Based Revision for West Virginia
Jackie Strager
Kurt Donaldson
Kevin Kuhn
April 24, 2007
Denver, CO
West Virginia GIS Technical Center
Natural Resource Analysis Center
West Virginia University
WV State GIS Coordinator’s Office

2. Introduction Status of NHD in West Virginia 33 sub-basins
Medium, high resolution NHD complete
Pilot projects underway for Local Resolution (LR) NHD creation

3. Local Resolution Pilot Project
Objectives
Meet with potential data users
Develop methods and standards
Assemble 1:4800 source data statewide
Assemble final LR-NHD for two pilot watersheds
Show benefits of LR-NHD for water resource applications

4. LR NHD Process Steps 1. Capture local hydro features
2. Data prep and revision
3. Pre-conflation steps
4. Conflation/QAQC steps
5. Ensure data stewardship

5. 1. Capture local hydro features
Statewide aerial photography, 2003
Contractor digitized hydro features from stereo pairs
Features with visible water only
Single-lined up to 50ft wide
Double-lined over 50ft wide
Lakes/ponds (min. 100ft wide)
Swamps/marshes
No name or code attributes
Correct flow direction
Edge-matched
Local scale hydro features
from SAMB photos
1:4800 streams
1:4800 polygons
Sutton Lake, WV

6. 2. Data prep/revision
Systematically examine contractor’s hydro data for incomplete and missing features
Close double-lined streams
Add DLG codes
Approximately 15-20% of streams were not adequately captured in source local datasets.
1:4800 streams in source
Additional 24K streams added

7. 3-4. Pre-conflation, conflation
For pilot watersheds:
USGS routines and NHD Geo-Conflation Toolkit (NHDGCT)
Pre-conflation
Conflation
QAQC
Load into national dataset

8. 5. Long term maintenance Involve interested cooperators
Encourage NHD stewardship process
Project communications
Show benefits of LR-NHD data
Website:

9. (approximated from SAMB stream data)
Benefits of LR NHD
Common data framework among NHD scales
Sutton Lake
1:100,000 scale NHD
Medium resolution
1:24,000 scale NHD
High resolution
1:4800 scale streams
Local resolution
(approximated from SAMB stream data)

10. Benefits Provides more highly detailed cartographic base
Flatwoods WV
24K NHD streams
LR NHD streams

11. Benefits More accurate source data Source for 24K NHD:
Big Chimney quad
Last revised: 1976
Source for LR NHD:
2003 Aerial photo
Revised LR NHD streams shown in yellow

12. Benefits Quantifies recent changes in stream drainage EPA:
24K NHD streams
LR NHD streams
Valley fill area
EPA:
Up to 1,200 miles of streams lost in multi-state mountaintop-removal mining region
Active mine permit, Lockwood quad

13. Benefits
Supports modeling of flow and hydrology at detailed local scale
More accurate stream mileage for stream mitigation projects, riparian buffers
Aids in floodplain mapping and emergency planning
More detailed dataset for resource management and planning, permitting, cumulative impact analysis

14. Benefits Supports WV legislative requirement
WV Water Resources Protection Act
Quantify nature and extent of water resources

15. Future Considerations
Completion of LR NHD
Cartographic issues
Edge-matching
Encouraging partnerships
Data stewardship
Updates, maintenance

16. Thank you!