GIS Data Preservation: Partnership with Library of Congress Steve Morris North Carolina State Univer

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GIS Data PreservationPartnership with Library
of Congress Steve MorrisNorth Carolina State
University Libraries
NCPMA Fall Meeting
October 11, 2006
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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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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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Time series Ortho imagery Vicinity of
Raleigh-Durham International Airport 1993-2002
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Digital Preservation Points of Failure

• Data is not saved, or
• cant be found, or
• media is obsolete, or
• media is corrupt, or
• format is obsolete, or
• file is corrupt, or
• meaning is lost

Solutions Migration Emulation Encapsulation XML
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Risks to 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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How would you describe your current geospatial
archive?
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NC Geospatial Data Archiving Project (NCGDAP)

• Partnership between university library (NCSU) and
  state agency (NCCGIA), with Library of Congress
  under the National Digital Information
  Infrastructure and Preservation Program (NDIIPP)
• One of 8 initial NDIIPP partnerships
• 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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(No Transcript)
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Geospatial data types Aerial imagery
85 NC counties with orthophotos 1-5 flights per
county 30-300 gb per flight
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Geospatial data types Vector tabular
Economic, infrastructure, and ethnographic data
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Geospatial data types Cartographic project files
Counterpart to the map is not just the dataset
but also models, symbolization, classification,
annotation, etc.
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Project Technical Approaches

• Receive data as is variety of distribution
  methods
• Migration of some at-risk formats
• Metadata remediation, standardization, and
  synchronization
• Distilling complex objects into repository ingest
  items (not easy)
• Build a digital repository (catalyst for
  discussion)
• Develop a repository ingest workflow (learning
  experience)

Some unsustainable activities for learning
experience
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Project Cultural/Organizational Approaches

• Engage data producer community and spatial data
  infrastructure through outreach and engagement
  influence practice
• Sell the problem to software vendors and
  standards development
• Find overlap with more compelling business
  problems disaster preparedness, business
  continuity, road building, etc.
• Start a discussion about roles at the local,
  state, and federal level

Current use and data sharing requirements not
archiving needs drive improved preservability
of content and improvement of metadata
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Challenge Coordinated Content Transfer

• How to allow one data snapshot to be accessible
  by multiple agencies more compelling use cases
  than preservation can put the data in motion
  (business continuity, disaster preparedness,
  etc.)
• Other activities? (DHS, WGRT, State Archives,
  Census, etc.)
• Question Capture frequency of data snapshot?
• Survey just completed to identify local
  government best practices, consumer agencies
  needs

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NC Frequency of Capture Survey

• Survey objective
• Document current practices for obtaining archival
  snapshots of county/municipal geospatial vector
  data layers
• Seek guidance about frequency of capture
• Survey topics
• General questions about data archiving practice
• Specific questions about parcels, street
  centerlines, jurisdictional boundaries, and
  zoning
• Survey subjects
• All 100 counties and 25 municipalities
• 58 response rate
• Survey conducted September 2006

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Survey Results Overview

• Two-thirds of responding agencies create and
  retain periodic snapshots
• Long-term retention more common in counties with
  larger populations
• Storage environments vary, with servers and
  CD-ROMs most common
• Offsite storage (or both onsite and offsite) is
  used by nearly half of the respondents
• Popularity of historic images has resulted in
  scanning and geo-referencing of hardcopy aerial
  photos among one-third of the respondents

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Local Business Rules and Uses Driving Temporal
Snapshotting

• Information technology policy (20)
• Records retention policy (18)
• Tax administration rules (25)
• Land use change analysis (11)
• Resolution of legal issues (18)
• Historic mapping (56)
• Other (30)

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Frequency of Capture Parcel Data
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Parcel Data Archival Data Format

• Shapefile (76)
• Geodatabase (36)
• Arc Coverage (29)
• Arc Interchange (7)
• Other (10)

52 of respondents indicated that a format
conversion was carried out in creating the
archival snapshot
Respondents were allowed to select multiple
formats
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Parcel Attribute Data Handling
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Digital Conversion of Hardcopy Resources

• Historic hardcopy maps
• Scanned only (15.5)
• Scanned and georeferenced (9.9)
• Aerial photos
• Scanned only (8.5)
• Scanned and georeferenced (26.8)
• None (54.9)

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Questions?
Contact Steve Morris Head, Digital Library
Initiatives NCSU Libraries Steven_Morris_at_ncsu.edu
Web site http//www.lib.ncsu.edu/ncgdap/