GIS Tool: Buffer Tool
/In episode 3 of the podcast, we talk about the Buf-fer Tool, Buf-Buf-fer Tool.
The buffer tool is one of many geoprocessing tools. Geoprocessing basically functions as a set of tools and a framework to perform analysis, modeling and management of your location data. The buffer tool in particular creates a buffer around an existing point, line, or area feature. For example, in episode 3 we talked to Emily Grason with Crab Team, who uses the buffer tool to create 20 meter buffers around each trap the Crab Team places. The traps are set once a European Green Crab sighting has been verified, and the location of the trap is collected with a handheld GPS unit. That coordinate is what is buffered, and Crab Team hopes they set the trap close enough to be within the crab’s territory (they typically don’t wander far during the summer months) so that the crab winds up in their trap.
To run the buffer tool in ArcMap, you need to specify an input layer (such as trap_locations), an output layer (such as trap_buffers), and either a buffer distance (in this case 20 meters) or a field that contains the buffer distance. There are other parameters, but they are optional and for most situations, cats can just accept the defaults. The tool will run, and a layer containing your buffers will be created, which you can use in further analysis! Easy, peasy! See the map below for a map of imaginary trap locations with their buffers. These traps didn’t catch any crabs, most likely due to the fact that they are imaginary. “Wait the crabs or the traps?” -P. Detective. “Duh, everything is imaginary…if you use your imagination, you can pretend that the coordinate is in the crosshairs in the map, the outer circle represents a very approximate approximation of a 20 meter buffer of each point,” -M. Mapper. Jen the Magical Mapper made this map in the free version of ArcGIS Online, which apparently has VERY limited capabilities (like no buffer tool available).
Always make the most of what you have, unless you can be a caticorn, and then it doesn’t matter how limited ArcGIS online is (cause you’re magical)!