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Pedon PC - Database Structure

If you encounter problems with the file provided on this page, please contact Soil Survey at 406-587-6818.

he information on this page is also available in Microsoft PowerPoint format. Once you have saved the file to a local drive, open Microsoft PowerPoint then open the saved file on your local drive.

Pedon PC Database Structure (PPT; 2.43 MB)

Pedon PC File Structure

4 Parts

  1. Pedon PC Front-End Application (INTERFACE)
    1. Spatial_link.mdb
      • Data Exchange for ArcMap
      • Prevents database locking when viewing data in ArcMap
    2. Pedon.mdb
      • Back-End Database
    3. Workspace Legend
      • Back-End Database
      • Holds working copy of component and mapunit legends

  1. Use Windows to browse to c:\pedon
  2. Open pedon_pc.mdb

Pedon PC Main Menu

Pedon PC Setup Menu

Relink Table
  • Updates table links.
  • Quick and easy way to change the source path of the table links for the Pedon and Workspace Legend databases.
  • Set the default path for Spatial Link database.
See Pedon Table Structure
  • Serves as a database structure learning tool.
  • Also allows domain choice show/hide.
Update Support Data
  • Updates NASIS supplied choice lists. Infrequently used.
Customize Choice Lists
  • Opens the choice list menu
  • Allows editing of choice list to suit local needs.
  • Allows retention of choice list edits made in another database. Used for:
    • Sharing choice list with another Pedon_PC user.
    • Retaining choice lists edits from a previous Pedon_PC version.
Export New Pedons
Backup/Restore Database
  • Not applicable in Alaska
  • See Pedon_PC UserGuide for instructions.

Pedon PC Import Menu

Import Data File from NASIS
  • Imports a flat-file exported as an ASCII report in NASIS.
  • Allows external editing of Pedon Data.
Imports Waypoints
  • Imports Waypoints from a .txt file created by DNR Garmin.
Link Photos/Points
  • Tool for managing and linking photos to records within the pedon database.

Pedon PC Forms Menu

Printable fieldsheet
  • Printable fieldsheet (Alaska standard)
  • Printable fieldsheet (Montana example)
NASIS Legend Builder
  • A “Workspace” mapunit and component legend manager.
  • Allows correlation and aggregation of mapunit composition and component horizon “layers.”
  • Used to build data-driven, model-oriented NASIS legends.
Transect Data Entry
  • Organizes pedons into transect “stops.”
Site Data Entry
  • Primary "site" data entry interface.
  • Allows 1 to 1 population of important horizon “child” records like texture, fragments, color, etc.
Analyze Point Data
  • Primary interface for in-depth point data analysis.
  • Basic understanding of SQL is required.
  • Features include custom-field naming, “drill-down” filtering, spatial filtering, and charts.

Pedon Database--Table Relationships

4 basic tiers of the database: site, observation, pedon, horizon

Site Table – Locational Information
  • The Site table is the “top” table in the database. It describes the locational information and characteristics of a particular geographic location.
  • A site may be a specific location such as a point where a soil profile description is taken, or it may have some spatial area that is chosen to be treated as a single point.
  • Various kinds of data such as soil profile descriptions, lab data, vegetative data, etc. may be linked to a site in this database.
  • Example Fields: User Site ID, Lat-Long, UTMs, Hillslope Profile, etc.
  • A Site record can have more than one Site Observation.
    • Example: A pedon is described in September 2005. The soil scientist returns to the site the following spring to check the depth to water table.
Site Observation Table – Temporal Information
  • The Site Observation table records the date that the various observation or analytical data is collected for the specific site or location.
  • Soil or site properties that may change with time are also recorded here. If a site is revisited at a later date for additional data collection, a new row with the appropriate date is entered in this table.
  • Separate tables exist for properties that may have multiple entries.
  • Example Fields: Date, Surface Water Depth, etc.
Pedon Table – General Profile Description Information
  • The Pedon table contains information collected at the time a soil profile description is made.
  • It has data that relates to the profile as a whole.
  • Examples: Soil Name (Component), Taxonomy, Describer, etc.
Pedon Horizon  – Profile Description Information
  • The Pedon Horizon table lists the horizons for each pedon.
  • Example Fields: Horizon Designation, Depths, pH, etc.

If the horizon thickness is greater than zero (low=5, RV=8, high=12), the horizon exists throughout the exposure of the profile.

If the horizon thickness includes zero (low=0, RV=1, high=3), the horizon may exist in some places, but may not exist in other places.

Horizons that have two distinct parts, such as E/B or E&Bt, are recorded twice. Once for the characteristics of the first part; and again on another row, using the same depths and thicknesses, for the characteristics of the other part.

Transect Table – Transect Information
  • The Transect table is used to record groupings of pedons that are the stops along transects.
  • A transect is NOT required for a site to exist.
  • Example Fields: Delineation Size, Selection Method, etc.
Site – Child tables
  • Each of these tables can have multiple records related to their “parent” site record
  • .
    • Parent Material (sitepm)
    • Geomorphic Description (sitegeomordesc)
      • Note: landscapes, landforms, anthropogenic features, and micro features are all recorded in the same table column. Only a geomorphic type differentiations them.
    • Site Area Overlap (siteaoverlap)
      • Site Mapunit Overlap (sitemuoverlap)
    • Site Text (sitetext)
Site Observation – Child tables
  • Each of these tables can have multiple records related to their “parent” site observation record.
    • Site Observation Text (siteobstext)
    • Site Soil Moisture (sitesoilmoist)
    • Site Soil Temperature (sitesoiltemp)
    • Site Erosion Accelerated (siteerosionacc)
    • Site Existing Vegetation (siteexistveg)
Pedon Horizon – Child tables
  • Each of these tables can have multiple records related to their “parent” pedon record.

Pedon Database – Table Relationships Structural Questions/Issues

Why record the mapunit symbol with a point (that has a spatial geometry)?
  • Notice that a site can “overlap” many areas (state, county, MLRA legend, Non-MLRA Legend, rainfall factor).
  • An area boundary can change.
  • An area can have many different mapunits.
  • Mapunit delineations can change.
What is another option?
  • Record the mapunit on a map.
  • Spatially intersect the map and point.
  • Describe the Mapunit in a Polygon Note or Mapunit Composition Note.
Why the one-to-many relationship between a site observation and a pedon?
  • In what instance would a pedon be described more than once on the same day at the same time in the same exact location?
The only available table for recording collected vegetation data is the siteexistveg table. Why isn’t there more?
  • Strata, Cover, and Production estimates could be included in the database by relating them to an individual species listed in the siteexistveg table.
  • The only structural modification to the database would be to add child tables under the siteexistveg table to house the data.
Why is there no place to store Mapunit/Polygon Composition estimates?
  • Pedon is a “point” database, composition describes a 2-dimension extent (spatial).
  • Alaska is storing their Polygon composition estimates in a linked “workspace legend” database.
Why not make a home for photo hyperlinks in the database?
  • Alaska is maintaining photo hyperlinks as site observation text notes under a “Photo” category.
  • Photos can be valuable site correlation tools and deserve their own table in the database.

Pedon PC File Structure - Exercises

  • Explore the Database Structure.
  • Navigate to Setup then See Pedon Table Structure
  • Clicking the + at the left of each record will expand the subdatasheet, showing any “child” tables. A Child table requires the “parent” record to exist first. Many child records can exist for the same parent record.
  • The Table Description explains the contents of the table.
  • double clicking the record selector at the left of the record opens a form that displays all of the fields for the selected table.
  • Clicking the + at the left of any column with a “domain id” will expand a subdatasheet showing the available choices for a given “domain.”

Exercise – Using the Link Manager to change the table links to a different dataset.

This process can now be done much faster using the Relink Tables option on the Setup menu, but it is still useful to know how to do it through the stock MS Access Link Manager.

  1. Expand the Tools Menu.
  2. Under Database Utilities, select the Linked Table Manager.
  3. Select all of the tables EXCEPT those tables with a “workspace” prefix.
    1. Select All
    2. Deselect all of the “workspace” tables by removing the checkmark in front of them.
  4. Place a checkmark next to “Always prompt for new location.”
  5. Click OK, then navigate to the PEDON database you wish to link to and click Open.
  6. When the linking completes, select ONLY the “workspace” tables and then repeat the steps, selecting the corresponding WORKSPACE database as the final step.

Exercise – Database Options

  1. Expand the Tools Menu
  2. Select Options
  3. View Tab
    1. Remove the checkmarks next to Hidden Objects and System Objects.
    2. This hides all the background queries, temporary tables, etc. used for some of the database utilities.
  4. General Tab
    1. Select the default database folder of your choice
    2. (defaulted to c:\pedon)
  5. Edit/Find Tab
    1. Remove the checkmarks next to:
      1. Record changes
      2. Document deletions
      3. Action queries
    2. NOTE: This turns off delete warnings database-wide.
      Think twice before touching the delete key.