The Disappearing Data ProblemSteve Morris Head of Digital Library InitiativesNorth Carolina State University Libraries

Problem: Preserving Digital Geospatial Data

• Industry focus on access to most current data• “Kill and fill” as common data management practice•Complex, multi-file/multi-format objects – hard to preserve•Shift to web services-based consumption – who builds the

archive?

Are we in the middle of

a “Digital Dark Age”?

Future uses of data are difficult to anticipate, as with circa 1900 Sanborn Maps.

Temporal Data Supports Business Needs

•Land use change analysis•Real estate trends analysis•Site selection (past uses?)•Economic planning

Parcel Boundary Changes 2001-2004North Raleigh, NC

What should the data

snapshot frequency be?

Challenges: Complex Data Representations

•Maps and spatial documents are more then the sum of the underlying datasets

•End products are combinations of datasets + application of symbology, classification, annotation, data models, etc. –difficult to preserve

The true counterpart to

the old map is not

the geospatial dataset

but rather the geospatial

project

Challenges: Geospatial Web Services

•Large volumes of data and rapid pace of update make web services or API access attractive

•Data increasingly ephemeral•OGC Web Map Context spec allows saving of application

state … but not data state

How does one document

decisions based on interactions

with constantly changing

web services?

Mashups, Web 2.0, etc.: New Opportunities

•Example: Web mashup interactions with existing systems spur creation of intermediate content layers: e.g., tiling and caching of WMS services

• Identification of a standard tiling scheme may create a new preservation opportunity (temporal axis on caches?)

Getting Started with “Geoarchiving”

•Library of Congress: National Digital Information Infrastructure and Preservation Program (NDIIPP) – addressing various digital content types

•North Carolina Geospatial Data Archiving Project (NCGDAP) – one of 8 initial NDIIPP partnerships

•… in partnership with NC OneMap which provides seamless access to state/local/federal data

How do we support “permanent access” – not just “bit preservation”?

Cultivating a market for older data.

Current access to and use of data

improves likelihood of longer-term preservation

Current access to and use of data

improves likelihood of longer-term preservation

Questions?

Contact: Steve Morris

Head, Digital Library Initiatives

NCSU Libraries

Steven_Morris@ncsu.edu

NCGDAP: http://www.lib.ncsu.edu/ncgdap

NDIIPP: http://www.digitalpreservation.gov/

NC OneMap: http://www.nconemap.net/