Claire DeVaughan U.S. Geological Survey NSDI Partnership Office Austin, Texas COGNA October 20, 2004 Integrating Local Data Sets into The National Map
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
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
Geocoding 1100 W 49 th Street, Austin TX gets converted to N Latitude and – W Longitude Process of assigning latitude and longitude to an address
The Geocoding Process Requires: –Address file (e.g. street address) –Street reference file (e.g. GDT, TIGER) –Geocoding software GIS applications Stand-alone applications
Geocoding Accuracy Levels Street County Census block 5-digit Zip Code 9-digit Zip Code
Editing Process: Utilizing ESRI’s 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
North Austin Medical Center, Austin
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
Alternative sources of information: Geographic Names Information System (GNIS) Local data sets Websites (mapping and hospital) Telephone
Texas Medical Center, Houston
Huntsville Memorial Hospital, Huntsville
Fisher County Hospital District, Rotan
North Runnels Hospital, Winters
Pecos County Memorial Hospital, Fort Stockton
For this project, the average distance from each geocoded point to each hospital’s approximate centroid was: 9-digit Zip Code accuracy level: –2.6 kilometers (1.5 miles) Street accuracy level: –221 meters (725 feet)
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 1:24K topographic maps
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
San Juan Cemetery, Caldwell County
Redwood Cemetery, Guadalupe County
San Pedro Cemetery, Hays County
Pitts Cemetery, Hays County
York Creek Cemetery, Comal County
Guadalupe Cemetery, Hays County
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
Who has local GIS data sets? Council of Government (fire and police stations, libraries, schools) Counties, cities Tax Appraisal District
Comments or Questions? Claire DeVaughan