The DLG attribute information available below includes multiple files that have been zipped together using PKZip. At a minimum there is a DBF file (dBASE version III) and a MS Word file both with attribute information concerning any specific layer such as Hydrology, as well as a readme file for that particular DLG layer. Depending on the data, there may be other files as well, such as the FIPS codes to be used with the political boundary information. All the information from the Word and readme files is also available in HTML format.
The DBF file was derived from several text files, as was the MS Word file; where information is duplicated in both files it will be identical. The MS Word file, however, contains more information than DBF file. This is due mostly to the nature of the data and a database. The DLG data when imported has major and minor codes, all classified as numerals. The text documentation had a mixture of text and numerals in the attribute code columns. This did not translate perfectly into a database format that could be used as a lookup table.
The original files documenting this data came from the U.S. Geologic Survey (USGS), as text files. There were two sets of files; the original documentation, and an updated version from 1995. The more recent documents are available on this site as well, in a zipped version. The files includes here are a combination of the new and old files. The DBF file contains ONLY the current (new) codes. The Word file contains the current data as well as notations on the older codes. BE AWARE that DLG data on the WWW may be new or old vintage, and may have old as well as new coding. With these two files you should be able to resolve conflicts over unclear codes.
In some cases the text description could be transformed into numerals; where this was fairly easy to do, such as the major code (feet, meters, etc) for hydrographic, water surface elevation, numerals were inserted into the DBF file. In all other cases, a 999 (for major codes) or 9999 (for minor codes) has been inserted into the location in the file where the text values were. The original values have been moved to the BEGINNING of the description field, and placed in parentheses (). An example of where this was necessary can be found in the political boundary information; listing all the FIPS codes for the counties would have made the file huge, so a separate file it included.
The most current documentation for each DLG layer is also included here. This documentation describes the codes, how they were derived, how they are defined; in other words it provided extensive background information on the creation and use of the data. This can be useful in interpreting unclear coding on the maps, and is interesting reading.
Detailed information on the DLG data in Spatial Data Transfer Standard (SDTS) format can be found in the SDTS section at http://www.fws.gov/data/gisconv/sdts2av.html
All files are zipped using PKZip, also available for download by clicking here (pkzipdoc.exe). Just type pkzipdoc and it will uncompress. To get a list of the command parameters just type pkunzip without any other commands, and you will get a simple list. Basic unzipping syntax is pkunzip filename.
EROS Data Center is the major Internet source for DLG data. The 1:100,000 data is in DLG-3 optional format. The 1:2,000,000 and 1:24,000 data are in SDTS format. The 1:2,000,000 data can be downloaded in Arc/Info format from http://water.usgs.gov/lookup/getgislist
Hydrology; (Hydrography)
DLG Hydrology Table of attribute information - dlghyupd.html.
Hydrology Readme file in readhy.html - or download dlghydro.zip Dbase III format (dlghydro.dbf) and
Word format (dlghyupd.doc) attribute information, and a readme file specific
to the data (readme.hy).
Hydrology Documentation (HTML format) - or download hy.doc
in Word format.
Hypsography
DLG Hypsography Table of attribute information - dlghpupd.html.
Hypsography Readme file in readhp.html - or download 100hypso.zip Dbase III format (100hypso.dbf) and
Word format (100hpupd.doc) attribute information, and a readme file specific
to the data (readme.hp).
Hypsography Documentation (HTML format) - or download
hp.doc in Word format.
Man Made features
DLG Man Made Features Table of attribute information - dlgmmupd.html.
Man Made Readme file in readmm.html - or download dlgmm.zip Dbase III format (dlgmm.dbf) and
MS Word 5.1 format (dglmmupd.wp) attribute information, and a readme file specific to
the data (readme.mm).
Man Made Documentation (HTML format) - or download mm.wp
in Word format.
Non-vegetative Features
DLG Non-Vegetative Features Table of attribute information dlgnvupd.html.
Non-Vegetative Readme file in readnv.html - or download dlgnv.zip Dbase III format (dlgnv.dbf) and
Word format (dglnvupd.doc) attribute information, and a readme file specific
to the data (readme.nv).
Non-Vegetative Documentation (HTML format) - or download
nv.doc in Word format.
Political Boundaries
DLG Political Boundary Table of attribute information dglbdupd.html.
Political Boundaries Readme file in readbd.html - or download 100bndry.zip Dbase III format (100bndry.dbf) and
Word (100bdupd.doc) attribute information, and a readme file specific to the
data (readme.bd).
Political Boundary Documentation (HTML format) - or download
bd.doc.
FIPS Codes - for states and counties in Dbase III format.
Public Land Survey System (PLSS)
DLG PLSS Table of attribute information dlgplupd.html.
PLSS Readme file in HTML format readpls.html - or download
100plss.zip Dbase III format (100plss.dbf) and
Word format (100plupd.doc) attribute information, and a readme file specific
to the data (readme.pls).
PLSS Documentation (HTML format) - or download plss.doc
in Word format. This includes the basic
documentation as well as Appendices A & B.
PLSS Appendices C & D - plssc_d.zip in Word
format. These are lists of land grant codes.
Survey Control and Monuments
DLG Survey Control and Monuments Table of attribute information dlgsvupd.html.
Survey Control and Monuments Readme file in HTML format readsv.html
- or download dlgsv.zip Dbase III
format (dlgsvm.dbf) and Word format (dlgsvmup.doc) attribute information, and
a readme file specific to
the data (readme.sv).
PLSS Documentation (HTML format) - or download sv.doc
in Word format.
Transportation
DLG Transportation; Pipelines, Transmission Lines, and Miscellaneous Features Table of
attribute information
dlgmtupd.html - or view the Transportation; Pipelines,
Transmission Lines, and Miscellaneous Documentation in mt.html
DLG Transportation; Railroad Features Table of attribute information dlgrrupd.html -
or view the Transportation; Railroads Documentation in rr.html.
DLG Transportation; Road and Trail Features Table of attribute information dlgrdupd.html - or view the
Transportation; Roads and Trails Documentation in rd.html.
Download the Transportation Documentation - in trans.wp
MS Word 5.1 format.
The Transportation Readme file, readtrn.html, contains
more detailed on Transportation files or you can download DLG Transportation
dlgtrans.zip - Dbase III format and Word (dlgtrupd.doc)
attribute information. Multiple
files are included in dbase format. One file, 100trans.dbf, contains all the attribute
codes. The others, 100trnrd.dbf,
100trnrr.dbf, and 100trnmt.dbf contain only the codes, respectively for roads and trails;
railroads; and pipelines,
transmission lines, and miscellaneous transportation features,and a readme file specific
to the data (readme.trn).
One possible method, 100trnav.html - to use the lookup tables
in ArcView to relate the tables.
Vegetative Surface Cover
DLG Vegetative Surface Cover Table of attribute information dlgscupd.html.
Vegetative Surface Cover Readme file in HTML format readsc.html
- or download dlgsc.zip Dbase III format
(dlgsc.dbf) and Word (dlgscupd.doc) attribute information, with a readme file
specific to the data.
Vegetative Surface Cover Documentation (HTML format) -
or download sc.doc in Word format.
For additional information regarding this Web page, contact Chris Lett, in the Division of Information Resources and Technology Management, at Chris_Lett@fws.gov
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Keywords=GIS, data, attribute, DLG
Last Modified January 03, 2001 08:39 AM