exploring your geospatial data. it’s all about relationships!

Exploring your geospatial data

It’s all about Relationships!

Download the SSURGO Template for your MMA

Two Important Points!

1. This is Not DIFFICULT!

2. The technology is not NEW!

What is new is our ability to look at theseenormous databasesin totally new ways.

Identifying slope inconsistencies in terrace soils Construct a Make Table query in Access using the cogeomordesc, component, and mapunit tables

Make MUKEY the first column in the output table

Output Access table

In ArcMap, join to the SSURGO attribute table using the MUKEY field

Select for all polygons that are terraces

Export the polygons to a feature class called terrace_soils

Open the SSURGO attribute table, and add a long integer field called objid

Double click on OBJECTID field to calculate objid = [OBJECTID]

Choose Zonal Statistics from the Spatial Analyst dropdown

• The Zone dataset will be terrace_soils• The Zone field will be objid• The Value raster will be the slope grid• Check the box to Join output table to

zone layer• Save the output table if you want• Click OK

• X the chart out• Look the table over, then close or

minimize it

Using mukey for the Zone field aggregates statistics by the mukey

Construct a SQL query to select polygons in which the representative slope value is more than 2 standard deviations greater or less than the mean slope within the polygon

Scale 1:35,114

So, you start with the cogeomordesc table here, see.

Yeah! Then you relate it to the component table, using the cokey field!

Then the mukey ties it all together!

Series extent, distribution and overlap

Join the SSURGO template mapunit table to the SSURGO attribute table using the MUKEY field

Select polygons LIKE ‘%Craig%’

The % sign is Arc’s wild card to match any characters that come before or after the character string ‘Craig’

Export the selected set to its own feature class

Tabulated areas are the number of 30 meter grid cells in each MMA. This table can be exported to .dbf, imported into Access or Excel, and acreages can be calculated.

Find SSURGO mapunits with lacustrine parent materials

Make MUKEY the first column in the output table

New Age – New Toys (Tools)

“You young pups with all your fancy play toys and whatnot….

“Back when I was a pup, all we had to play with was an old cat’s head”

Any questions?

• Use the help screens in Arc• Use relationships for all kinds of queries• Use all the tools available—Access, ArcGIS, ArcCatalog,

Excel• Step away from the machine• Resources:

– Access user guides at

http://soils.usda.gov/technical/access/

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