The buffer geoprocessing tool reveals areas on the map that are within a specified distance of other features. This is a common task that greatly enhances the analysis of proximity.
- [Presenter] One of the most common things that people want to visualize on a map is to see what areas are nearby features of interest. You might want to see what waterways are within 100 yards of a storm water outflow pipe, or how many restaurants are within walking distance of a new stadium. To visualize these types of distances we can create a boundary around an input feature using a geoprocessing tool called Buffer. For this example I want to find out what areas of the city of Seattle are within a quarter mile of a school building. On this map schools, university, college, and kindergarten buildings have already been extracted from a larger data set of all of the buildings in Seattle.
Next we need to activate the Buffer tool. To find it, let's take a look at the Analysis tab on the ribbon, and we'll take a look at the tools group here in the middle. The most common geoprocessing tasks are listed here. You can scroll through this list using these up and down arrows on this side of the screen, or you can press the downward-pointing arrow at the bottom and see the full list here. The one that I want is called Buffer, which you can find in the Determine Proximity section there. Before we do, though, let me show you a few other things before we launch the tool. Go ahead and come down to the bottom and choose More Tools.
That will open up the geoprocessing pane on the right hand side of the screen. Know that this is the same pane that opens up if you press the Tools button back on the Analysis tab. On the first section of the pane you'll see all the tools that have been marked Favorite. For the full list, switch over to the Toolboxes tab. This will let you view and explore all of the categories and drill down to find the tools that you want. You can find the Buffer geoprocessing tool under Analysis Tools, Proximity, and it's there at the top of the list. If you wanted to you can right click on it and choose Add to Favorites, and then it'll show up on the Favorites list of the beginning of the pane.
Another way to find the tool is to come up to the Find Tools search box and just type in the name. I'll type in Buffer here, press enter, and the search results shows me the Buffer tool, which is in the Analysis Tools group. So pick your favorite method and go ahead and start a Buffer processing tool. I'll just click on it from the search results. Next we need to supply a couple of parameters for the tool. The Input Features are going to be the features that we want to find the Buffer around. In our case the school buildings, so I'll use the drop down list and choose Seattle OSM schools, and OSM just indicates that these schools originally came from Open Street Map.
Next we need to specify where we want the results to go. By default it's going to go into our Projects Geo-Database. I can go ahead and click on this line here and then scroll across to see the results of that, we can see it's going into the Chapter_04 folder, the 04_02_Buffer folder, and then the Seattle geo-database. If we keep scrolling to the very end we'll see the name that'll get applied to the feature class. In this case Seattle underscore OSM underscore schools, underscore Buffer. If we wanted to we could change it, but that's a fine name so I'll go ahead and leave it the way it is. Next we get to specify the distance that we want to buffer around our features.
I want to see the results of a quarter mile buffer, so I'll type in .25, then from the Units drop down, I'll choose Miles. We'll skip down to the Dissolve Type option, and instead of No Dissolve, I'll choose Dissolve all output features into a single feature. This will merge areas together that overlap into a single feature. This will make all of the buildings contribute to a single one mile buffer feature, rather than having a one mile buffer around each individual building. When you're ready, go ahead and press the Run button, and the Buffer tool will process. When the buffer completes it'll be added to the map as a new layer with the same symbology, or colors, as the original input layers.
So we can see the Seattle OSM School's buffer has this purple color, which is the same as the original schools layer. If we switch over to the Project pane by clicking the tab at the bottom right hand side of the screen and get into our Databases folder, we can expand the Seattle geodatabase and see that we have a new feature class here for our Buffer feature. So now using this buffer, it's easy to visualize what areas in the city of Seattle are within a quarter mile of a school building. The buffer analysis geoprocessing tool is a very common tool that can support a wide variety of visualization needs. For instance, you can run multiple buffers at increasing distances to visualize things, such as the rings around an earthquake epicenter at one, five, and ten miles out.
There are lots of situations where the Buffer tool can come in handy.
- Creating a new map project
- Adding data sources to the project
- Managing data layers on the map
- Saving a project template
- Drawing new map features
- Querying and extracting features
- Creating geoprocessing models and packages
- Modifying the look and feel of the map through symbology options
- Adding map labels
- Working with 3D scenes
- Developing a map layout
- Sharing the map and data