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I am interested in downloading and using the entire USGS SSURGO database.
The California Soil Resource Lab provides instructions on working with these data in R, but it starts with the assumption that I have downloaded tables as .csv files - but doesn't say how to get these files, other than that the metadata is available as an Access template
Can I download the entire SSURGO database? Is it available in formats other than csv + Access?
It is possible to import the SSURGO database into PostgreSQL, it is just not terribly easy. As answered in response to your other question, the SSURGO data can be downloaded by state. The information for some states (e.g., CA) will be too big and will need to be downloaded by county; multiple counties can be selected. Once the downloaded information is extracted from its archive, the spatial data are a collection of shapefiles and the tabular data are a collection of flat ASCII files (fields separated by '|').
The SSURGO metadata explains the relationships of tables (Data Model Diagram and Relations Report), table fields and their respective data type (Tables and Columns Report), and detailed column descriptions (Table Columns Description Report). Using this information it is possible to create the appropriate tables and import both the spatial and tabular data. I was able to import the mupolygon (polygon shapefile), mapunit, component, and coecoclass tables for the western US into PostgreSQL. SQL script for creating the above tables, bash script (rudimentary) for iterating over the downloaded data and importing into PostgreSQL, and SQL script for cleaning up the import.
If you go through the USDA website where they give you access to SSURGO, it's kind of a mess. They make you go all the way down to the county level.
If you go through the NRCS Data Gateway you can define an area of interest with a bounding box. The data is also available for download by state. Over the last couple of months the SSURGO data has been hit or miss (if you go to 'Contact Us' they usually tell you which databases are down).
Just a heads up - the national dataset is going to be pretty substantial when it comes to disk space / network load if you get all of the tabular data too. It might be better to work in chunks anyway in case you lose the connection.
Unfortunately, I do not think so. At least not at this time. We are trying to work with the data to get best-available estimates of soil parameters for portions of the south central US, and it has been a time-consuming, slow process to both merge the shapefiles together to cover larger areas, and to read the associated tabular data such that it can be converted into the values we need.
If you care to go about downloading the individual soil areas from NRCS's Web Soil Survey Portal, you can click the Download Soils Data tab and get the raw tabular and spatial files per area.
I have built a python tool to scan the downloaded, unzipped folders and import the data into a PostGIS database (or update the data therein). You can find the tool here.
Abe,
I have worked and performed my SSURGO for the state of New Mexico because I work for NRCS. Before I give you how to do the steps, I ran the internet and found this and this pdf will probably be very useful for you. This is similar what I did.
Tutorial for SSURGO download from Purdue
You will probably need to go to NRCS Geospatial Data Gateway to select all or some soil survey area spatial and tabular SSURGO soils data. This might charge you since you are not part of USDA employee or any Federal agency. You might check that out with the California NRCS for further information. If you know someone or an organization that might have the data and get copy of it.
Once you download all of the spatial and tabular from the data mart. Open the MS Access that you save the template database. You will probably see a warning dialog box and be sure to enable it. Make sure you make a copy and back it up in the event you messed it up.
Before you start importing all the database, it is wise to save a new MS Access database file like this for example SSURGO_CA.mdb.
When you import a database, the easiest way to do is to open the Window Explorer and copy the path of the tabular folder and paste it (on page 8) in the SSURGO Import dialog box. It save me a lot of my time. When it is done imported, make sure you save it as a SSURGO_CA.mdb for each tabular you download.
If you forgot or not sure which soil survey area you have import or not, you can open the access file and look for the names you have imported it there.
Let me know if you need help, Wish you the best luck !
Note that the links to the CA Soil Resource pages have recently changed. Please use the search feature on the new site to find relevant material. Please see my suggestions in a related question.
It is the USDA NRCS Soils Database, not USGS. And, yes, you can obtain the entire dataset, both spatial and attribute.
This site provides the Ordering Information for the Soil Data Mart database. The SDM is the publication database used by the various web portals.
However, the SDM database is more than you will need and it is best to use the Soil Data Access site to query the specific information you need and download for import into your project.
