Spatially Balanced Sample Design Tool For support using this tool, email Sarah McCord and Nelson Stauffer: smccord@nmsu.edu and ngs@nmsu.edu Send all GIS files used for AIM sample design to Sarah Burnett: sburnett@blm.gov Including input files and output files

This is the landing page for the tool It needs a .zip file containing a polygon shapefile of the strata clipped to the sample frame—just the part of the landscape where points can actually be drawn e.g. only BLM ownership within a field office boundary.

So, this an example of strata from the Taos Field Office for their project

This is what the contents of the. zip need to include This is what the contents of the .zip need to include. These are all the files that make up a polygon shapefile exported from ArcGIS software. Definitely do not put these files in a folder that you then put into the .zip file The shapefile has a field for the stratum in its attribute table. This is important because the tool will need to be told that field so it knows what stratum a polygon belongs to.

This is all that happens when you upload This is all that happens when you upload. Note that it’s already trying to figure out what the stratification field is. It always guesses the first one in the attribute table.

Select the correct field, in this case the “dominant stratum,” and then hit the button “3) Press to select field & plot”

It may take a few moments, but wait for the map to appear to confirm your selection. The plot size refers to how large the tool will plot this map figure and has no relationship to the selection of the survey locations. You can ignore it while working with the tool.

If you select unequal points, you can adjust the numbers with the sliders. Otherwise all strata will get the same number of points. Unequal point selection is common in large scale designs, but on smaller scales (just a few thousand acres versus several tens of thousands or more) equal selection is normal.

You can enter the number of base points per stratum and how many overdraw/sample points then hit “Fetch Points!” Note that these fields are only if you chose to not use the unequal point selection option.

Once they’ve been fetched, the tool will show the map with the points on it Black are base, red are overdraw/sample Download the point shapefile (it’ll be a .zip to extract to the folder of choice)

Results on the map Green = base, red = overdraw

Highlights of the attribute table are fields for: Stratum, weight, coordinates, and plot name (called “sample” and unlikely to be helpful as-is fresh from the tool; renaming usually happens at the BLM National Operations Center for AIM projects)