Mapping Your Land and Introduction to Web Soil Survey Elizabeth Cook GIS Specialist USDA-NRCS (retired)
Using Geographic Information Systems (GIS), Global Positioning System (GPS), digital aerial photography and other data and tools for better land management Not just pretty maps analyses! All landowners can and should be using these tools in some form or fashion.
Start with some basics of WHY you would use these tools, but not the technical details Suspend your anxieties, for awhile, about HOW to accomplish what I am going to talk about Concentrate on the USES these applications would have to you and the management of your land
Where do you begin? Map the perimeter boundary of ownership Aerial photography and eyeball in the perimeter boundary using digitizing tools Request the CLU (common land unit) shapefile from USDA Request tax parcel data from county (Missouri only has a few counties with digital tax parcel data; often there is a charge for the data or it is proprietary) Use a metes and bounds description from a paper land survey and GIS tools that interpret it into a polygon perimeter Import a CAD-generated digital survey boundary (.dwg) Walk the boundary of your property collecting waypoints with a GPS unit
Example: Spring Hill Woodlands LLC in Noble Co., Ohio No comprehensive land survey Legal descriptions (metes and bounds) were piecemeal, and of varying age and accuracy In wooded areas, just eyeballing the boundary is not good enough Digital tax parcel data is proprietary Decided to begin with CLU and use GPS for any required modifications
USDA-FSA CLU boundary provided to landowner Internal field boundaries have been removed
Map internal management units CLU fields Heads-up digitize from photography GPS Purpose: Acres of management units Further analyses
https://websoilsurvey.nrcs.usda.gov/app/homepage.htm
Can use on-screen digitizing to create field boundaries if you do not have a shapefile Once you create polygons on-screen, they can be exported to a shapefile for further use WSS tools will clip and download soils for use with other GIS data on your computer Print results as map with table data, or as a complete custom report using the shopping cart Use Soil Data Explorer for interpretations of soils data
Missouri Black Walnut Suitability Index Laclede Co. example
NW Corner of Laclede Co, MO
Beyond Soils Analyses of your Land using GIS Modeling slope and aspect from elevation data Aerial photography changes over time from time-sequence imagery Exclusion areas such as stream buffers
Management unit boundaries overlaying an elevation model in hillshade format
22% ave. slope
Combining data: Ex. Forested areas, southwest aspect, less than 20% slope
Time to talk some of technical stuff
GIS Software Literally, as many options as there are people in this room (or more) Desktop vs. web-based Desktop software and data on local computer; most desktop software also has a webbased component Web-based software and most data over Internet; usually, web-based is more functionally limited and less spatially accurate, but more user friendly Free vs. fee
Web-Based Web Soil Survey optimized for soils data but has other useful functions; better than other web-based GIS because NRCS developed it for accurate spatial assessments Google Earth can import boundaries from formats such as shapefiles; often has higher resolution and/or newer aerial photography than public domain data; but not as much spatial integrity for measuring; VIEWER, not an analysis tool https://www.google.com/earth/download/ge/agree.html to download free viewer software
ArcGIS Online www.arcgis.com/home Can create a free online account; hundreds of base maps with great cartography available, but limited analysis; can import own shapefiles; again, largely a VIEWER
Desktop Software Free ArcExplorer free version of ArcGIS; limited analysis functionality; larger a VIEWER QGIS gvsig Whitebox GAT Saga GRASS MapWindow fgis Avenza MapMyLand rated as best by GIS community Customized for forestry applications
Desktop Software ArcGIS for $100/year for personal use Full functionality that otherwise costs thousands of dollars Largest GIS community in world; interface skills and data with government users at USDA, USGS, MDC and many more Can use in concert with Arc Online resources Complex software; not very user-friendly
Global Positioning System (GPS) Units Cell phone apps no measurable accuracy; no antennae to boost signal in canopy Hand-held units, such as Garmin Background maps Accuracy measurement Converts to other data formats (.gpx) Transfer cables to computer Cost $200-400
Data Resources (for Desktop GIS) https://gdg.sc.egov.usda.gov/ - download site for USDA; includes imagery, elevation, climate, land cover, transportation, hydrography data and more State and county-based files; select download package and the site sends an email when ready for download Many files are large (100s of megabytes) http://msdis.missouri.edu/ Similar functionality, more variety of data; does have a clip function to download smaller areas of data County USDA offices and possibly county government offices
Elizabeth Cook eacjeg@mediacombb.net (573) 353-2728