Claire DeVaughan

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Integrating Local Data Sets into The National Map

• Claire DeVaughan
• U.S. Geological Survey
• NSDI Partnership Office
• Austin, Texas

COGNA
October 20, 2004
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Collaborative Projects

• Hospital Preparedness Data Set
• - Texas Department of Health (TDH)
• Critical Infrastructure Data Collection
• - Texas State University graduate level
  GIS class
• - TX Dept of Information Resources

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Hospital Data Project Background

• Hospital Preparedness File owned by Texas
  Department of Health (TDH)
• Created for Homeland Security
• 577 hospitals
• Geocoded locations
• Variable accuracy
• Goal To improve the positional accuracy of the
  data

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Geocoding
Process of assigning latitude and longitude to an
address
1100 W 49th Street, Austin TX 78756 gets
converted to 30.8215N Latitude and 97.735514W
Longitude
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The Geocoding Process

• Requires
• Address file (e.g. street address)
• Street reference file (e.g. GDT, TIGER)
• Geocoding software
• GIS applications
• Stand-alone applications

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Geocoding Accuracy Levels

• Street
• County
• Census block
• 5-digit Zip Code
• 9-digit Zip Code

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Editing Process

• Utilizing ESRIs ArcMap 8.3
• View hospital data and Digital Ortho Quarter
  Quads (DOQQs)
• Zoom in to each hospital (stored as a point
  feature)
• Move the point feature to the correct location

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North Austin Medical Center, Austin
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Problems encountered

• Unable to locate hospital on DOQQs
• Cluttered urban areas
• DOQQs are dated 1995/1996
• Address data not complete or inaccurate
• Misspelled street name
• Street reference data quality issues
• Incomplete
• Incorrect

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Alternative sources of information

• Geographic Names Information System (GNIS)
• Local data sets
• Websites (mapping and hospital)
• Telephone

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Texas Medical Center, Houston
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(No Transcript)
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Huntsville Memorial Hospital, Huntsville
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Fisher County Hospital District, Rotan
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North Runnels Hospital, Winters
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Pecos County Memorial Hospital, Fort Stockton
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For this project, the average distance from each
geocoded point to each hospitals approximate
centroid was

• 9-digit Zip Code accuracy level
• 2.6 kilometers (1.5 miles)
• Street accuracy level
• 221 meters (725 feet)

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Critical Infrastructure Project

• Goal Establish methodology for collection of
  location and attributes
• San Marcos study area 21.5 sq mi, population of
  40,000
• Base data was provided to the class, including
  GNIS, a local dataset, and USGS 124K topographic
  maps

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Methods

• City of San Marcos street data and geocoding
  service in ArcMap
• Geocoding using geocode.com (Tele Atlas address
  database)
• GPS data collection variety of GPS receivers,
  ranging from 200- 4,000

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San Juan Cemetery, Caldwell County
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Redwood Cemetery, Guadalupe County
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San Pedro Cemetery, Hays County
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Pitts Cemetery, Hays County
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York Creek Cemetery, Comal County
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Guadalupe Cemetery, Hays County
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Who has State GIS data sets?

• Education agencies (schools)
• Health department (hospitals, clinics)
• Dept. of Transportation (bridges)
• Parks and Wildlife Dept.
• Dept. of Environmental Quality
• Historical Commission
• Universities
• Department of Public Safety

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Who has local GIS data sets?

• Council of Government (fire and police stations,
  libraries, schools)
• Counties, cities
• Tax Appraisal District

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Comments orQuestions?

• Claire DeVaughan
• cdevaugh_at_usgs.gov
• 512-927-3583