Instructions for downloading and displaying smooth-grid trend files from BBS data
Instructions for downloading and displaying
smooth-grid trend files from BBS data
- Download files:
- Unzip (extract) the files usacanab.zip,bbsgrid.zip, and grid_trend.zip
- Add Themes usacanab.shp and bbsgrid.shp to an Arcview project.
- In the Project window, select Add Table. Choose to
List Files of Type: Delimited Text (*.txt), select the file with the AOU number
of your species of
interest, and click OK.
- On the new Table, select the column labeled grid_code. On the Table
Attributes of bbsgrid, select the same column. Click the Join button on the toolbar (Ctrl+ J).
The data for your species should
now be associated with the BBS grid shapefile as a
new column in its Table, labeled tr* (* indicating the AOU number of your
species).
- On the left side of your View, double-click on the theme usacanab.shp.
Load the legend file usacanab.avl, then click Apply.
Returning to the View, double-click on the Theme bbsgrid.shp and Load the legend file
gridtrendlegend.avl.
When asked to choose a Field, select tr* and All, then click OK, then Apply.
With both Themes displayed
(bbsgrid.shp on top), you should now see a map of the U.S. and Canada
overlaid with BBS grid, which will grade in color according to
the percent change per year of the selected species during 1966-2002.
To view this information for a different species, repeat steps 4-6 above, using the
appropriate AOU number.
The shape files have the
projection:
Parameter | Value |
Projection | Albers |
datum | nad83 |
units | meters |
1st standard parallel | 29 30 00 |
2nd standard parallel | 45 30 00 |
central meridian | -96 00 00 |
latitude of projection's origin | 23 0 0 |
false easting | 0 |
>false northing | 0 |