|
What is GIS Data
Welcome to the Flathead National Forest GIS Data Library.
Geographic Information Systems (GIS) is a computer-based tool for
mapping and analyzing objects and events. It combines the power of
tabular and spatial databases with the visualization capabilities offered
by maps. GIS provides the power to solve complicated problems,
experiment with scenarios and present ideas. The digital data is available
on line free of charge. Just click on the .zip file that is contained within
the individual data tables. Many of these files are large, so please check
the file size listed before downloading. All data files have been compressed
with the WinZip compression utility. PC users can use a zip utility such
as WinZip to unzip these files.
GIS Data Disclaimer
The Forest Service uses the most current and complete data available.
GIS data and product accuracy may vary. They may be: developed from
sources of differing accuracy, accurate only at certain scales, based on
modeling or interpretation, incomplete while being created or revised, etc.
Using GIS products for purposes other than those for which they were
created, may yield inaccurate or misleading results. The Forest Service
reserves the right to correct, update, modify, or replace, GIS products
without notification.
How to Use the GIS Data
The Geographic datasets covering the Flathead National Forest are now
available online. The Flathead National Forest uses ESRI's GIS software
(ArcInfo, ArcGIS), and stores all corporate GIS data in one of ESRI's
proprietary formats (shapefiles). The datasets available online are stored
as zipped shapefiles to conserve space and facilitate download. To use
them, you must uncompress them using winzip or other compression
software that recognizes these file types. You may then import them into
ArcInfo coverages if needed. In addition to their commercial software,
ESRI offers ArcExplorer software free for importing and viewing coverages
and shapefiles. You can download the software from their web site:
www.esri.com/software/arcexplorer/index.html
Spatial Data
Spatial Data is provided in ArcView shapefile format. These files can be
used in ArcGIS, ArcView, or ArcExplorer GIS software packages.
ArcExplorer is a free spatial data viewer that can read Arc/Info data sets.
There is a free import utility that will import Arc/Info export files available
from www.esri.com. Many other GIS and graphics software packages
have a utility to import these files.
Tabular Data
Tabular Data is generally provided in dBase IV format. These files can be
imported into Arc/Info, ArcView, or ArcExplorer GIS software packages
and joined to their associated gis coverages. An additional file containing
documentation may be included with the tabular data.
What is Metadata?
Metadata is data about data. Users are strongly advised to read the metadata
to insure the data set is appropriate for their needs. Click on .htm in the
metadata column of the data set of interest to view the metadata. Each
metatdata will provide a general description of the data set, geographic
information about the data set, how the data set was built, any updates to
the data set, any associated database tables with the data set, descriptions
of data set attributes, and other valuable information.
About the Online Themes
Unless otherwise noted, all datasets are single, forestwide coverages, and
are in NAD83 UTM Zone 12 projection. This data represents the best data
currently available at the forest. It is not necessarily complete and accuracy
is limited to 1:24000 USGS cartographic standards or less. The Forest
Service does not guarantee the accuracy or currency of any of this data.
As the forest's database is updated or requests for data change, this list will
be updated.
More Information
Contact our Forest GIS Coordinator (406)758-5239
|
