All data for one or more soil survey areas can be deleted by running the macro named “Drop Soil Survey Area”.  The Drop Soil Survey Area form displays all soil survey areas that currently reside in the database.  To delete all data for one or more soil survey areas, select the soil survey area, or areas, whose data you wish to drop, and then click the button labeled “Drop”.  Multiple contiguous (contiguous in the form’s selection list) soil survey areas can be selected using <Shift>Click, or by clicking and dragging.  Multiple noncontiguous soil survey areas can be selected using <Ctrl>Click.

The main reason for dropping data for a soil survey area is the case where your database currently contains data for a particular soil survey area, and you want to update that data from a newer export.  The import process is not currently capable of performing an update, so any existing data for a particular soil survey area must be deleted before updated data for that same soil survey area can be imported.

The Drop Soil Survey Area process does not reclaim the space occupied by the deleted data, and if data is dropped and reloaded enough times, the size of the database may become an issue.  Of course an existing database can always be compacted by selecting “Database Utilities: Compact Database” from the Tools menu in MS Access.
Any soil data exported from Web Soil Survey includes a file named “version.txt”.  The contents of this file is used to determine if the data a user is about to import into a SSURGO Template database is compatible with that database, and whether or not any accompanying metadata should be imported.

File “version.txt” contains a single line in the form number.number.number.

The first number is the SSURGO Version.  See section “SSURGO Version” in this same report for additional information.

The second number is the Import Data Model Version.  See section “Import Data Model Version” in this same report for addition information.

The third number is the Metadata Version.  See section “Base Metadata Version” in this same report for additional information.

Every version of a SSURGO Template database where the SSURGO Template database version is greater than or equal to 36 “knows” what SSURGO Version and Import Data Model Version it is compatible with.

No data will be imported unless both the SSURGO Version and the Import Data Model Version in file “version.txt” match what is expected.

Metadata will not be imported unless the Metadata Version in file version.txt is greater than the Base Metadata Version of the SSURGO Template database in question.  This prevents obsolete metadata from being imported.

For those of you responsible for creating and/or updating SSURGO Template databases, ExpectedSSURGOVersion, ExpectedImportDataModelVersion and BaseMetadataVersion are defined in the Declarations section of Module “Import Procedures”.
Base Metadata Version, for a given combination of SSURGO Version and Import Data Model Version, indicates the version of the metadata in a SSURGO Template database, at the time that SSURGO Template database was released.

The metadata in a SSURGO Template database includes the metadata for all tables that are part of the SSURGO standard, as well as the metadata for selected tables that are not part of the SSURGO standard.

This metadata resides in the following tables in a SSURGO Template database:

mdstatdommas – Metadata pertaining to all domains referenced by the columns of selected tables in a SSURGO Template database.

mdstatdomdet – Metadata pertaining to the members of all domains referenced by the columns of selected tables in a SSURGO Template database.

mdstattabs – Metadata pertaining to selected tables in a SSURGO Template database.

mdstattabcols – Metadata pertaining to the columns in selected tables in a SSURGO Template database.

mdstatidxmas – Metadata pertaining to the primary keys, unique constraints and indexes associated with selected tables in a SSURGO Template database.

mdstatidxdet – Metadata pertaining to the columns included in the primary keys, unique constraints and indexes associated with selected tables in a SSURGO Template database.

mdstatrshipmas – Metadata pertaining to the relationships between selected tables in a SSURGO Template database.

mdstatrshipdet – Metadata pertaining to the columns on which selected tables in a SSURGO Template database are related.

When data is imported into a SSURGO Template database, metadata is not updated unless the Metadata Version of the data being imported is greater than the Base Metadata Version of that SSURGO Template database.

For a given combination of SSURGO Version and Import Data Model Version, the corresponding Base Metadata Version may be incremented over time.

Whenever SSURGO Version or Import Data Model Version changes, Base Metadata Version should be reset to 1.
Import Data Model Version, for a given SSURGO Version, corresponds to the data model of all of the data that can potentially be imported into a SSURGO Template database.

A data model defines a collection of tables, columns, unique constraints, and the relationships between the tables in that collection.  The Import Data Model Version encompasses all tables in a SSURGO Template database that are part of the corresponding SSURGO standard, as well as a number of tables in a SSURGO Template database that are not part of the corresponding SSURGO standard.

Import Data Model Version, in conjunction with SSURGO Version is used to determine if the data a user is about to import into a SSURGO Template database is compatible with that database.  If either the SSURGO Version or the Import Data Model Version in file “version.txt” doesn’t match what is expected, that data cannot be imported.  This prevents data that is not in the proper format from being imported into a SSURGO Template database.

For a given SSURGO Version, the corresponding Import Data Model Version may be incremented over time.

Whenever SSURGO Version changes, Import Data Model Version should be reset to 1.
Questions about this database should be directed to the Soils Hotline.  The Soils Hotline, which resides at the National Soil Survey Center in Lincoln Nebraska, is typically staffed from 8:00 AM to 4:30 PM Central Time.

(402) 437-5378 – Steve Speidel
(402) 437-5379 – Tammy Cheever

e-mail:  soilshotline@lin.usda.gov
SSURGO Version identifies the general organization of the soil data that are considered to be part of the SSURGO standard.  The SSURGO standard encompasses which soil attributes, domains and tables are defined, as well as the relationships between those tables.  The SSURGO standard encompasses both tabular and spatial data.

Only a subset of the tables in a SSURGO Template database are part of the SSURGO standard.  For example, the tables in a SSURGO Template database that are used to drive the Soil Data Viewer application are not considered to be part of the SSURGO standard.

To date, there have been only two SSURGO versions:

SSURGO 2

In this version of SSURGO, released in early 2001, the structure of the tabular data reflected the structure of the National Soil Information System Database (NASIS).  The structure of the spatial data was still that of SSURGO 1.0.  The SSURGO tabular data could now be loaded into an MS Access SSURGO template database.  Spatial data was now available in ArcView Shape File format.

SSURGO 1

In the original version of SSURGO, the structure of the tabular data reflected the structure of the State Soil Survey Database (SSSD), the predecessor of NASIS (National Soil Information System).  There was no corresponding MS Access SSURGO template database.  Spatial data was available as an Arc/Info Coverage, as an Arc/Info Export File or in Modified Digital Line Graph 3 format.  Coordinate system/projection was fixed.

Whenever a new SSURGO Version is released, both Import Data Model Version and Base Metadata Version should be reset to 1.
The template database version is the overall version of ALL tables, queries, forms, reports, macros and modules in the underlying MS Access template database.  Although there is always a new template database version when something changes in the SSURGO standard, the template database version can also change when nothing in the SSURGO standard has changed.  In fact, the template database version changes much more frequently than the SSURGO version does.

This MS Access template database is just one of a number of possible alternatives for delivering SSURGO data.  This database implementation is not part of the SSURGO standard, per se.

When corrections or enhancements are made to this database, the template database version is always updated.  The system report “Template Database Change History” records the changes associated with a particular template database version.
This database has not been secured in any way.  Therefore there is no security to prevent the deletion or modification of any existing database object (table, query, form, report, macro or module).  Because so many database objects are referenced from multiple locations, deleting or modifying an existing database object may result in the unanticipated disabling of certain database objects or functions.

If you want to alter or customize this database, we suggest that you do so by always creating new database objects.  Of course you can always make a copy of an existing object, and give it a different name, in order to modify an existing database object.  A document is available that describes recommended practices when customizing this database.  This document has been checked into:

CoLab > NRCS-Soils-DB-CC > Documents > SSURGO > SSURGO Template Database Customization Guide

Please contact the Soils Hotline at soilshotline@lin.usda.gov to request a copy.

Before you commit to making a lot of customizations, please keep in mind that this SSURGO template database is frequently updated and enhanced.  See the system report titled “Template Database Change History” for the gory details.  If you want to keep relatively current with the latest version of the template database, you will be responsible for reapplying your customizations to new versions of the template database.
This database was developed in order to facilitate the delivery and use of soil survey data for USDA Natural Resources Conservation Service end-users and cooperators.  This database may be used stand-alone or in conjunction with the Soil Data Viewer application.  The underlying data structure corresponds to the SSURGO version identified in the report named “How to Understand and Use this Database”.  Although a SSURGO product typically represents both the tabular and spatial aspects of a correlated and published soil survey area, this database may also be used to deliver tabular data for a soil survey area where mapping or updating is still in progress.