Transcript Slide 1

The NHD and the Future of
Stream Mapping in West Virginia
Evan Fedorko
West Virginia GIS Technical Center
www.wvgis.wvu.edu
Jackie Strager (NRAC)
www.nrac.wvu.edu
Kevin Kuhn
Kurt Donaldson
WVGISTC
Introduction
• Outline:
– Existing stream map: 24K NHD
• Issues with 24K NHD
– Current stream mapping: Local NHD
• Pilot projects, results and future plans
– What’s next: Stewardship and the future of NHD
• NHD successes and challenges
– Case study: Stream modifications in the Coal River
• Future of NHD
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Introduction
NHD 24K
NHD local
Stewardship
NHD Status in WV
• National Hydrography Dataset (NHD)
• NHD is complete in WV for:
– Medium resolution (1:100,000 scale)
– High resolution (1:24,000)
• Local resolution NHD (1:4,800)
– Pilot projects complete
– Gauley
– Upper Guyandotte
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Introduction
NHD 24K
NHD local
Stewardship
Evaluating the NHD
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• What could be improved in 24K NHD in WV?
• How was this determined?
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Track known issues (NRAC)
Stream naming/coding process (NRAC/WVDEP)
Systematic statewide review by WVDEP
Case study: mining impacts in the Coal River
watershed (stewardship section)
Introduction
NHD 24K
NHD local
Stewardship
Issues with 24K NHD
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• Main Issues:
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Errors in geometry
Errors in attributes
Errors in NHD formatting, reach coding
Changes in stream geometry since streams were
mapped
• Source data for 24K NHD:
– 24K DLG data
– Topo map blue lines
– GNIS names
Introduction
NHD 24K
NHD local
Stewardship
The big picture…
Quantifying issues
with the NHD
Primarily based on
WVDEP review
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Introduction
NHD 24K
NHD local
Stewardship
The big picture…
Quantifying issues
with the NHD
Primarily based on
WVDEP review
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Introduction
NHD 24K
NHD local
Stewardship
The big picture (2)…
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• Quantifying 24K NHD issues as identified by
WVDEP review
Type of problem
Possible geometry error
NHD attribute error (FCODE)
Karst/sinking streams
NHD format error (reaches)
Name issues (possible)
Name issues
TOTAL
Number of
Segments
% of
Segments
Total Length
(mi)
614
0.28
254
6
0.00
3
291
0.13
107
6
0.00
n/a
204
0.09
89
1,337
0.62
657
216,579
94,796
Introduction
NHD 24K
NHD local
Stewardship
Local resolution NHD
• Local streams mapped from 2003 SAMB aerial
photography and 3m DEM
• Benefits:
– Better cartographic base for local mapping
– Captures changes in stream geometry, length
• Status:
– Pilot projects complete for Gauley, Upper Guyandotte
watersheds in late 2008
– Not currently downloadable from USGS
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Introduction
NHD 24K
NHD local
Stewardship
LR-NHD Conclusions
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Introduction
NHD 24K
NHD local
Stewardship
• Two pilot watersheds completed – not available
for download yet
• WV is the first state to complete conflation using
USGS’ new (beta) conflation tools
• At this time, continued development of LR NHD
is NOT recommended. Summary of reasons:
– Issues with 1:4,800 scale source data – inconsistent collection
and inclusion of “special features” such as ditches and culverts
– Comparative difficulty of conflation process
– Propagation of HR-NHD errors
– General lack of interest by the WV NHD community
– The persistent generalization question
– Continued changes in stream geometry
Future of NHD for WV…
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Introduction
NHD 24K
NHD local
Stewardship
• Goal: Establish a stewardship program for NHD
in WV
– Data updates
– Ensures data maintenance
– Central point of contact
• Steps taken:
– Drafted a business plan for NHD in WV
– Drafted an MOU between potential NHD steward and
the USGS
– Working with potential NHD steward
Stewardship Status
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Introduction
NHD 24K
NHD local
Stewardship
• Successes
– Completed business plan for NHD
– Stakeholders have been engaged in an active
discussion
– Survey conducted in 2008 revealed a great deal of
interest in establishing a stewardship program
Stewardship Status
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Introduction
NHD 24K
NHD local
Stewardship
• Challenges
– Data policy issues within potential stewardship
agency
– Community concerns over what scale of data will be
maintained – fear that preferred scale will be “left
behind”
– Front loading of needed edits to HR-NHD resulting in
initial…
– Challenge of funding and personnel commitment to
NHD stewardship
Coal River case study
• Goal: Quantify amount of stream drainage
change related to mining for southern WV
watershed
• Input datasets:
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24K NHD stream lines
1:4,800 local stream lines
2003 SAMB aerial photos
2007 NAIP aerial photos
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Introduction
NHD 24K
NHD local
Stewardship
Original 24K NHD
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Introduction
NHD 24K
NHD local
Stewardship
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2003 Aerial photos
2003
Photo
Introduction
NHD 24K
NHD local
Stewardship
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Mining visible in 2003
2003
Photo
Introduction
NHD 24K
NHD local
Stewardship
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Aerial photos 2007
2007
Photo
Introduction
NHD 24K
NHD local
Stewardship
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Mining visible 2007
2007
Photo
Introduction
NHD 24K
NHD local
Stewardship
Summary for 24K NHD in Coal
Description
Entire Coal watershed
Impacted by mining (2003)
Impacted by newer mining
(2007)
Area
(acres)
Length of
24K streams
(mi)
570,000
2,232
12,321
10,757
59
33
Coal case study: Local
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Introduction
NHD 24K
NHD local
Stewardship
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Coal case study: Local
Description
Entire Coal watershed
Area
(acres)
Length of
streams
(mi)
Length of
streams
(mi)
24K
1:4,800
Introduction
NHD 24K
NHD local
Stewardship
570,000
2,232
2,829
Impacted by mining (2003)
12,321
59
n/a
Impacted by newer mining
(2007)
10,757
33
38
Stewardship
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Introduction
NHD 24K
NHD local
Stewardship
• West Virginia’s next steps
– Identify principal steward(s)
– Consolidate key stakeholders and come to consensus
on key issues
– Implement stewardship plan
– Compile errors and begin editing
Discussion
Natural Resource Analysis Center
West Virginia University
www.nrac.wvu.edu
WV GIS Technical Center
West Virginia University
wvgis.wvu.edu