SSURGO Download Instructions (Last updated 1999, some links may not work)

The following are step by step instructions for downloading SSURGO certified soil data from the Internet. It is assumed that the user has experience using GIS and is familiar with soil survey information. These instructions are for using the ArcView GIS software from ESRI to view the maps but other GIS programs should also work. There are also numerous shareware GIS programs available for free, which should also work. If you plan on using the soil coverages with the MassGIS Data Viewer, you should request the soil data on CD in Arc format this way the coverages will overlay and join accurately. Following these instructions are directions on how to change projections using an ArcView script but this does not always work and the coverages may not join.

These instructions are a bit lengthy so you may want to print this out:

  1. First got to the National Soil Data Access Facility web site:
    http://www.statlab.iastate.edu/soils/nsdaf/
    Click on SSURGO under Soil Geographic Databases:
    http://www.ftw.nrcs.usda.gov/ssur_data.html
  2. If you need more information about SSURGO try exploring this site, there is a lot more information there. Download the Soil Survey Geographic Data Base users guide for reference (VERY IMPORTANT).
  3. Click on download SSURGO data, this will take you to:
    http://www.ftw.nrcs.usda.gov/ssur_ftp.html
  4. Fill out the information request form (optional) this will provide the agency with information to aid in future developments of the program. Select "Download SSURGO data", this will take you to: ftp://ftp.ftw.nrcs.usda.gov/pub/ssurgo/online98 (of course you can always just click here to jumpstart once you are familiar with the web site structure.
  5. From here click on the (directory) Data Folder (data is alphabetized by State, scroll to MA610 for - Hampden and Hampshire Counties, Massachusetts or MA616 for - Norfolk and Suffolk Counties, Massachusetts
  6. From this site you will find the following zip files for downloading (note: some of these are very large files):

    cov.zip
    dlg27.zip: Digital line graph, NAD 27.
    dlg83.zip: Digital line graph, NAD 83.
    Doc: Links to metadata.
    out.zip: Arc/INFO export files (.e00)
    readme: Complete information on SSURGO structure.
    tab: Links to each interpretive data text files such as map unit, yields, etc.

  7. Download the out.zip file to a directory on your hard drive. This file has the Arc/INFO export files (Arc interchange format) which will be imported into the ArcView program.
  8. Once the file has been downloaded extract the zip file using a zip program. There should be numerous files ending with the extension .e00 such as interp.e00, and mapunit.e00. Each of these files can be converted to coverages and/or tables and used in the ArcView program.
  9. You can import the soil mapping coverage by either a specific USGS Quadrangle or by the entire county. If you have a lot of memory and a fast computer you may want to import the whole county, this is stored in the file ma610_a.e00 (Hampden and Hampshire counties) or ma616_a.e00 (Norfolk and Suffolk counties). If you are only working in a small area you can import a specific USGS Quadrangle, these files are labeled with a lowercase s followed by a number such as s4107106_0a.e00.
    A brief description of the naming convention for individual quads are as follows:
    Sample File Name: tyyxxxzz_qt
    t - indicates type of data (s = SSURGO)
    yy - indicates southeast latitude of the one-degree block in which the quadrangle resides.
    xxx - indicates southeast longitude of the one-degree block in which the quadrangle resides.
    zz - is the 7.5-minute section number of the one-degree block in which the quadrangle resides (reading left to right from northwest corner).
    _q - indicates the 3.75-minute quarter of the 7.5- minute quadrangle expressed as an integer (7.5-minute quadrangles are coded as "0")
    NE - 1
    NW - 2
    SW - 3
    SE - 4
    t - indicates data type: (a - soil polygons, p - special soil point features, l - special soil line features).
  10. To view the coverages in the ArcView program use the Import71 utility that comes with the Arc/View program (Start- Programs- ESRI- ArcView Version 3.0- Import71). Specify the export (.e00) file you want to import, then select the directory to put it into. Data coordinates for Arc interchange files vary with the geographic extent. Coordinates for quadrangle coverages are in UTM meters. Coordinates for survey area wide coverages are in Geographic decimal degrees. Both are referenced to the North American Datum of 1983. As mentioned earlier these coverages may not overlay onto the MassGIS data viewer because of differences in quadline clipping and projections, you should order the soil coverages CD from MassGIS to match the data viewer.
  • The coverage you just imported can be viewed using the ArcView program. Start ArcView, click on the "ADD THEME" button and navigate to the directory you imported the file to. The only information you will get from the soil maps is polygon information and a map unit symbol such as "310B", this is the State-wide map unit symbol. To view the map unit symbol double click the soil coverage (or select "THEME", "EDIT LEGEND"), in the "LEGEND TYPE", select "UNIQUE VALUE", then under "VALUES FIELD", select Musym. To show more information such as interpretive maps or various theme maps you will need to join the soil map attribute table with other tables downloaded with the soil coverages. The common field to join tables should be the Musym field.

    Using SSURGO data with other data available from the Mass/GIS Data Viewer

    If you try to overlay the SSURGO soil maps with other maps on the Mass/GIS data viewer the maps may not be aligned. This is because they may be in different coordinate systems. SSURGO data is in UTM coordinates and Mass/GIS data is in Mass. State Plane, NAD 83 coordinates. To overlay the maps you need to match coordinate systems, here's how:

    NOTE: If you have arc/view 3.1 or greater, use the projection utility wizard to reproject your data from UTM to State Plane.

    •
    1. There is an Arc/View extension called prjctr.avx which comes with the program, this is a very useful extension used to change map projections to various coordinate systems. The prjctr.ave extension is not one of the default extensions on the Arc/View progam so you will need to make it one. To do this use Windows Explorer to drag the extension into the Ext32 folder. The prjctr.avx file is in the C:\ESRI\AV_GIS30\ARCVIEW\Samples\ext directory. Simply locate this file and drag it into the C:\ESRI\AV_GIS30\ARCVIEW\EXT32 directory. Exit Windows Explorer and start Arc/View.
    2. Click on the File, then Extension menu and click on Projector!
    3. Next, add the coverage you want to convert to the State Plane coordinate system. You must first select units for the View, click on View, then Properties, then under Map Units select Meters, do the same with Distance Units. Make the Theme active, click on the change projection icon/button (this is the projector extension you just added, should be a button with an arrow pointing north).
    4. When you click the projector button it will ask you to select the input projection in the next dialog box, click OK. Under the Category, select UTM, under the Type box select Zone 19 for the Norfolk County data or zone 18 for H&H, click OK, it will prompt you to pick out-put units, select meters, click OK. Next you will select the projection properties: under Category select State Plane - 1983, under type select Massachusetts Mainland, click OK.
    5. It will ask you if you want to recalculate area, perimeter, etc, click OK then it will ask if you want to add projected shapefile as them to view click OK. Give the theme shape file a name then click OK.

    This new shape file is now in Massachusetts State Plane coordinates NAD 83 and should overlay or match in with other data available from MASSGIS such as the orthophotos, scanned usgs topos or other theme/data.

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