The Digital Atlas of
Texas Counties was developed to provide a
map-based information resource and demonstrate the
utility of county-level Internet map services.
The atlas is based upon data
available in the public domain - largely TIGER-based
data from the U.S. Census Bureau and elevation data from
the U.S. Geological Survey.
There are four versions of
the atlas:
The County Basemap Series is
a simple set of maps showing the base layers for each
county. The Shaded Relief Map Series adds a digital
elevation model (DEM) and hillshade to depict county
terrain. Lastly,
the Satellite Relief Map Series uses Landsat imagery to
provide an overview of county landuse.
All three map series were
produced in a 17 x 24 inch format.
Map Services
The digital atlas contains 254 map services,
one for each county in the state. The map
services were created from 254 map documents
built in a VB6 programming environment.
A customized ArcIMS interface was
developed to display the map services.
Hardcopy Maps
Once the original map documents were
complete, programs were written to copy and
modify the .mxd’s to create the hardcopy maps
for each map series.
This effort involved programming the
development of map layouts with the use of
different layers, symbology and labeling.
Database
Both the map services and the hardcopy maps
use ArcSDE to access the data layers stored in
an Microsoft SQL database.
