In response to Jeff Hamerlinck's STATSGO query:
Greetings from Idaho !
SCS has done quite a few things with the STATSGO database. A good
contact person would be Fred Minzenmayer at the National Cartography
and GIS Center in Ft. Worth, TX, at 817-334-5559, ext. 3008. Fred
put a lot of work into a STATSGO/GRASS interface for Ver 4.0 of
GRASS and would be able to tell you if there is an update to Ver 4.1
of GRASS or what ARC interfaces may be in existence.
I have written many GRASS scripts to query the one-to-many relates
of the STATSGO database; such as determining dominant pH values for
a region or dominant surface textures. Most STATSGO queries, though,
I rely on the Interface to handle for me.
I have also written a few DBASE IV programs to query the ARC/INFO
coverage on percentage polygon composition, slopes, and texture
ranges for polygons in a project area.
STATSGO data is complicated to work with. I recently gave a paper
at the NW ARC/INFO Users Conference on manipulating the data. I
stressed how it is essential that each query to the database be based
on the premise that you are trying to find out what percentage of soils
in an area meet the criteria you are looking for. In other words, each
query should have some sort of the following logic: "Show me all areas
in which more than (or less than) x % of the soils meet the following
criteria". Also, picking dominant soil characteristics can be a very
deceiving task, since the dominant percentage for a polygon may only be
15 % of the STATSGO mapping unit.
If this has confused you even more, please contact myself or Fred. I
would be glad to discuss this in more detail with you and to see what
kind of applications you are doing with this data.
David Hoover
Manager, Cartography and GIS Section
USDA-SCS, Idaho State Office
Boise, Idaho
208-334-1525
ATT Mail Address : !a16dhoover