Preserving State and Local Government Digital Geospatial Data Steve Morris Head of Digital Library Initiatives North Carolina State University Libraries

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Preserving State and Local Government Digital
Geospatial Data Steve MorrisHead of Digital
Library InitiativesNorth Carolina State
University Libraries
ALA NDIIPP Symposium
June 25, 2007
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NC Geospatial Data Archiving Project

• Partnership between university library (NCSU) and
  state agency (NC Center for Geographic
  Information Analysis)
• Focus on state and local geospatial content in
  North Carolina (state demonstration)
• Tied to NC OneMap initiative, which provides for
  seamless access to data, metadata, and
  inventories
• Objective engage existing state/federal
  geospatial data infrastructures in preservation

Serve as catalyst for discussion within industry
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NCGDAP Targeted Content

• Resource Types
• GIS vector (point/line/polygon) data
• Digital orthophotography
• Digital maps
• Tabular data (e.g. assessment data)
• Content Producers
• Mostly state, local, regional agencies
• Some university, not-for-profit, commercial
• Selected local federal projects

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Targeted data Vector data

• 98 of 100 NC counties have GIS
• More detailed, accurate, current
• Subject to frequent update

• Cadastral (tax parcels)
• Street centerlines
• Zoning
• Topographic contours
• School, sheriff, fire
• Voting precincts
• More

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Targeted data Digital orthophotography

• 90 NC counties with orthophotos
• 1-5 flights per county
• 30-300 gb per flight

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Targeted data Cartographic

• GIS Software
• Software project file (.mxd, .apr, )
• Data layer file (.avl, .lyr, )
• PDF map exports
• Web Services-based representations

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Not yet targeted data Place-based data
Oblique Imagery

• Mobile, LBS, and, social networking applications
• Long-term cultural heritage value in non-overhead
  imagery more descriptive of place and
  function

Street View Images
Tax Dept. Photos
DOT Videologs
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Risks to Digital Geospatial Data
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.dgn
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.sid
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Risks to State/Local Geospatial Data

• Producer focus on current data
• Data overwrite as common practice
• Future support of data formats in question
• No open, supported format for vector data
• Shift to web services-based access
• Data becoming more ephemeral
• Inadequate or nonexistent metadata
• Impedes discovery and use
• Increasing use of spatial databases for data
  management
• The whole is greater than the sum of the parts

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Local Applications Where GIS Is Used
Source NC OneMap Data Inventory 2004
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Temporal Data Supports Decision-Making

• Land use change analysis
• Real estate trend analysis
• Site selection
• (past uses?)
• Forecasting

Parcel Boundary Changes 2001-2004 North Raleigh,
NC
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Temporal Data Supports Decision-Making
Suburban Development 1993/2002 Near
Mecklenburg-Cabarrus County border
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Wake County, NC Interstate 540 / US Highway 70
Interchange Near Raleigh/Durham International
Airport
2005 Wake County Ortho
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(No Transcript)
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Todays geospatial data as tomorrows cultural
heritage
Future uses of data are difficult to anticipate
(as with Sanborn Maps).
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Challenge Vector Data Formats

• No widely-supported, open vector formats for
  geospatial data
• Spatial Data Transfer Standard (SDTS) not widely
  supported
• Geography Markup Language (GML) diversity of
  application schemas and profiles threatens
  permanent access
• Spatial Databases
• The whole is more than the sum of the parts, and
  the whole is very difficult to preserve
• Can export individual data layers for curation
• Some thinking of using the spatial database as
  the primary archival platform

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Challenge Cartographic Representation
Counterpart to the map is not just the dataset
but also models, symbolization, classification,
annotation, etc.
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Challenge Geospatial Web Services

• How to capture records from decision-
• making processes?
• Possible Atlas collections from automated
• image capture
• Web 2.0 impact Emerging tiling and
• caching schemes (archive target?)

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Challenge Preservation Metadata
Results from a 2006 survey of all 100 NC counties
and 25 largest NC municipalities
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NCGDAP Project Directions

• Working with state spatial data infrastructure on
  content exchange mechanisms
• Infrastructure being created for other business
  reasons
• Benefit to archive in terms of lower acquisition
  costs, better metadata, established provennance
• Co-established the Data Preservation Working
  Group in the Open Geospatial Consortium
• Insert temporal use cases into specification
  processes
• Collaboration with State Archives
• Work towards infusing local records outreach and
  records retention with geospatial components

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Questions?
Steve Morris Head, Digital Library
Initiatives NCSU Libraries ph (919)
515-1361 Steven_Morris_at_ncsu.edu http//www.lib.nc
su.edu/ncgdap