- Video length: 1:50
- This video was created with ArcGIS Pro 1.4.
In this tutorial, you'll use geoprocessing tools to solve a spatial problem. Geoprocessing tools are essential for spatial analysis although they have many other uses as well. Spatial analysis includes activities like comparing places, determining how places are related, finding best locations and paths, detecting patterns, and making predictions. Spatial analysis usually involves a chain of reasoning. This means that geoprocessing tools are often run in sequence to solve a problem.
Most geoprocessing tools work on an input dataset to create a new output dataset. The output may be a spatial dataset or a stand-alone table. Some tools instead modify the attributes or geometry of an input dataset. A few tools have other effects, such as creating selections on layers or generating messages or reports.
ArcGIS Pro 2.0 is recommended. The tutorial project file will open in earlier versions of ArcGIS Pro; however, the tutorial steps in the online help reflect the current software release. If you have an earlier software version, use the offline help system to open the tutorial. To switch from the online to the offline help system, see About ArcGIS Pro Help.
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Data for all quick-start tutorials is included in one download. To download the data, follow these steps:
Open the project
Nassella tussock is an invasive weed accidentally brought to New Zealand in the late 1800s. It is now well-established in the Marlborough and Canterbury regions. It spreads quickly, crowds out other grasses, and is hard to eradicate. It is unpalatable to livestock, which makes it a threat to pastoral farming. Nassella tussock seeds are spread mainly by wind, but also by animals, people, and vehicles.
In this tutorial, you'll look for Nassella tussock growing near commercial campgrounds (campgrounds for motorhomes). Campers who come in contact with the weed during recreational activities may inadvertently get seeds in their clothing or gear and take these seeds with them when they leave. If your analysis shows that Nassella tussock grows near commercial campgrounds, agriculture officials can provide information to help campers identify and avoid it.
The analysis has three parts. First, you'll create buffers, or proximity zones, around the commercial campgrounds. Next, you'll see which of these buffers contain Nassella tussock. Finally, you'll calculate the amount of Nassella tussock within the buffers.
- Start ArcGIS Pro and sign in if necessary.
- On the start page, under your recent projects, click Open another project.
- On the Open page, under Open, click Computer and click Browse .
- On the Open Project dialog box, browse to Use_geoprocessing_tools.aprx and click OK.
The file will be in a tutorial data folder with the same name, such as C:\ArcGISProQuickstartData\Use_geoprocessing_tools.
The project opens to the Marlborough region of New Zealand. Commercial campgrounds are displayed along with the known distribution of Nassella tussock. Be aware that the Nassella Tussock Range layer does not represent the density of the plant at a given location. A marked area may be heavily infested or it may have only scattered plants.
Open the Geoprocessing pane
To carry out the analysis, you'll run tools from the Geoprocessing pane. First, you'll see how these tools are organized in ArcGIS Pro.
- On the ribbon, click the Analysis tab. In the Geoprocessing group, click Tools .
The Geoprocessing pane opens. Under Favorites, some common geoprocessing tools, including Buffer, are readily accessible.
- In the Geoprocessing pane, click the Toolboxes tab.
You see a list of toolboxes organized by category.
- Browse to Analysis Tools > Proximity.
A toolbox may contain built-in tools , script tools , or model tools . It may also contain toolsets , which are smaller containers of tools. See Geoprocessing vocabulary to learn more about tool types.
The Proximity toolset contains tools for analyzing distances between and around features.
- In the Proximity toolset, click Buffer.
The Buffer tool opens in the Geoprocessing pane. Like all tools, it has options or parameters that need to be set. Required parameters are marked with a red asterisk. Some parameters are blank; others have default values.
- Hover over the Help button .
A ScreenTip describes and illustrates the tool. The Buffer tool creates distance zones around features. Buffers are typically used to find features in one layer near features in another layer. In this case, you will look for Nassella tussock near campgrounds.
Buffer the commercial campgrounds
Now you'll set the parameters and run the tool.
- On the Buffer tool, click the Input Features drop-down list and click Commercial Campgrounds.
The Side Type and End Type parameters are removed because they are not used when the input features are points.
- Change the default Output Feature Class name to Campground_Buffers.
When you hover over the Output Feature Class parameter, the full path to the project geodatabase is displayed. You can either highlight and replace the dataset name at the end of the path or delete the entire path and type the new feature class name. The full path will be restored automatically when the tool is run.
- In the Distance [value or field] box, type 1.5.
- Click the adjacent drop-down list of distance units and click Kilometers.
The tool will create a new polygon feature class containing fourteen buffer features—one for each campground. The buffer features will be circles of a 1.5-kilometer radius centered on the campgrounds. Your assumption is that campers are most likely to come in contact with Nassella tussock on walks and bike rides.
- Hover over any tool parameter, such as Method or Dissolve Type.
An information icon appears next to the parameter.
When you hover over the icon, it displays a description of the parameter and its settings. In this case, you'll accept the default values for the Method and Dissolve Type parameters.
- At the bottom of the Geoprocessing pane, click Run.
When the tool successfully finishes running, a green check mark appears next to the tool name at the bottom of the Geoprocessing pane. The Campground_Buffers feature class is created in your project geodatabase and a new layer is added to the map. At the current map scale, the buffers are probably obscured by the campground symbols.
- In the Contents pane, turn off the Commercial Campgrounds layer.
- Right-click the Campground_Buffers layer and click Zoom To Layer .
To see Nassella tussock inside the buffers, you need to change the symbology of the Campground_Buffers layer.
- In the Contents pane, click the symbol for the Campground_Buffers layer to open the Symbology pane.
- In the Symbology pane, on the Gallery tab, scroll down through the list of symbols and click Black Outline (1pt).
The symbols are updated on the map.
- Close the Symbology pane.
- In the Contents pane, right-click the Campground_Buffers layer and click Attribute Table .
The name and address attributes of the features have been copied from the corresponding commercial campgrounds. The BUFF_DIST field shows the buffer distance expressed in meters.
- Close the attribute table.
- Zoom in and examine some buffers at close range to see whether they contain Nassella tussock.
- When you're finished, on the ribbon, click the Map tab. In the Navigate group, click Bookmarks and click Campgrounds.
- On the Quick Access Toolbar, click the Save button to save the project. If you get an ArcGIS Project prompt asking if you want to proceed, click Yes.
Select buffers containing Nassella tussock
The next part of the analysis is to identify the buffers that contain Nassella tussock. For this, you need a tool that finds features in one layer (Campground_Buffers) according to whether they have area in common with features in another layer (Nassella Tussock Range). In the Geoprocessing pane, you can search for tools with keywords. In this case, keywords such as contain, inside, or within might help you.
- In the Geoprocessing pane, click the Back button .
- At the top of the pane, in the search box, type contain.
A handful of results are returned. The Select Layer By Location tool should be among them.
- In the list of search results, hover over Select Layer By Location to see its description.
The ScreenTip tells you that the tool selects features in one layer based on a spatial relationship to features in another layer. This sounds like what you want.
- In the Geoprocessing pane, click Select Layer By Location to open the tool.
- On the tool, click the Help button to open its help topic.
In the help topic, the Summary and Usage sections give general information about the tool. The Syntax section describes its parameters.
A key parameter for this tool is the spatial relationship to be evaluated—depending on the situation, you may want to know whether features intersect, contain, touch, or lie within a certain distance of other features? Here, containment might seem to be the right relationship: you want to find campground buffers that contain Nassella tussock. However, this choice would be too restrictive. Imagine a patch of Nassella tussock lying partly inside and partly outside a buffer. This patch is relevant to your analysis, but the buffer does not contain it—it only intersects it. On the other hand, if a patch lies entirely inside a buffer, the buffer both contains and intersects it. Therefore, you should use the intersect relationship.
For illustrations of how spatial relationships are defined with respect to different feature types (points, lines, and polygons), see Select By Location: graphic examples.
- Close the help topic.
- Click the Input Feature Layer drop-down list and click Campground_Buffers.
- Confirm that the Relationship is set to Intersect.
- Click the Selecting Features drop-down list and click Nassella Tussock Range.
The features in the input feature layer are the ones that will be selected. This is the correct setting: you want to know which campgrounds are affected, not which patches of Nassella tussock are affected. There is no output feature class parameter because the Select Layer By Location tool does not create a new dataset—it makes a selection on the input feature layer.
- At the bottom of the Geoprocessing pane, click Run.
Four buffers are selected on the map. The number is confirmed by the message in the lower right corner of the map view.
It may not surprise you that two of the selected buffers lie in areas where Nassella tussock is prevalent. But what about the other two? Do the four selected buffers have a geographic relationship that sets them apart from the others?
- In the Contents pane, turn on the Roads layer and expand it.
The four selected buffers are linked by principal highways. This suggests that the road network facilitates the spread of Nassella tussock. On the other hand, many unselected buffers are also linked by highways. It would be interesting to know which campgrounds are visited most often and whether vacationers typically visit multiple campgrounds, but these questions are beyond the scope of this tutorial.
- Turn off the Roads layer and turn on the Populated Places layer.
Three of the four selected buffers intersect populated places. At the same time, many populated places have no Nassella tussock near them. While this brief investigation was inconclusive, spatial selections are a good way to discover meaningful patterns in your data and stimulate ideas for further analysis.
- Turn off the Populated Places layer.
- On the Quick Access Toolbar, click Save .
Quantify Nassella tussock within buffers
In the third part of the analysis, you want to find out how much Nassella tussock lies within the selected buffers. Why does that matter? For public education, it might be useful to provide campgrounds with a bulletin on whether Nassella tussock has been found in the area, and, if it has been found, whether or not it is widespread. For researchers, a quantitative measurement is a baseline for comparison in coming years.
The tool you will use is Summarize Within. You might find this tool with a keyword search in the Geoprocessing pane—for example, the keyword within returns it. However, in this case you'll open the tool from the Analysis gallery. The Analysis gallery is a convenient place to access a number of frequently used analysis tools.
- On the ribbon, click the Analysis tab.
- In the Tools group, expand the Analysis gallery.
- Under Summarize Data, hover over the Summarize Within tool and read its description.
One of its functions is to calculate how much area in polygons from one layer falls within polygons from another layer—this is what you want to do.
- Click Summarize Within to open the tool in the Geoprocessing pane.
- Click the Input Polygons drop-down list and click Campground_Buffers.
When there is a selection on the input layer, geoprocessing tools work on the selected features only. In this case, only the four selected campground buffers will be processed and written to the output feature class. This is what you want—you already know that the other campground buffers don't contain Nassella tussock.
- Click the Input Summary Features drop-down list and click Nassella Tussock Range.
- For Output Feature Class, change the name to Tussock_Within_Buffers.
Like the Buffer tool, the Summarize Within tool creates a new feature class. The output features will have the same shapes as the input features. The only difference will be in the attribute table.
- Click the Shape Unit drop-down list and click Hectares.
A hectare is a metric unit of area equal to 10,000 square meters or roughly two and a half acres.
- Click Run.
When the tool completes successfully, the Tussock_Within_Buffers feature class is created in your project geodatabase and a layer is added to your map.
- On the ribbon, click the Map tab. In the Selection group, click Clear .
- In the Contents pane, turn off the Campground_Buffers layer.
The Tussock_Within_Buffers layer has four features, corresponding to the four selected campground buffers. You'll change the symbol for the layer so you can see through it.
- In the Contents pane, click the symbol for the Tussock_Within_Buffers layer to open the Symbology pane.
- In the Symbology pane, on the Gallery tab, scroll toward the bottom of the symbol list and click Extent Transparent.
- Close the Symbology pane and the Geoprocessing pane.
- In the Contents pane, right-click the Tussock_Within_Buffers layer and click Attribute Table.
The Summarized area in HECTARES field shows the analysis results. Keep in mind that the Nassella Tussock Range layer represents areas within which the plant has been found, not the actual plant density.
Visualize analysis results
In this study, you have a small number of samples and it's easy to compare them in the attribute table. However, with more samples, charts are a more useful—and visually interesting—tool for comparisons. You'll create a bar chart of the analysis results.
- In the Contents pane, right-click the Tussock_Within_Buffers layer. Click Create Chart and click Bar Chart .
The Chart Properties pane opens and the Tussock_Within_Buffers: Bar Chart 1 view opens. The view is empty until you make settings in the Chart Properties pane.
- Near the top of the Chart Properties pane, confirm that the Data tab is selected. Click the Category or Date drop-down arrow and click Name.
In the chart view, the campground names appear on the chart's x-axis. At the moment, the chart displays the number of names per campground (which is 1). You need to choose the field values that you want to chart.
- In the Chart Properties pane, under Series, confirm that the option From one or more fields is selected. Click the Fields drop-down arrow and click Summarized area in HECTARES.
The chart's y-axis and data bars update to show the area covered by Nassella tussock near each campground.
- At the top of the Chart Properties pane, click the General tab.
- In the Chart title box, replace the current title with Nassella Tussock Near Commercial Campgrounds and press Enter.
The title is updated on the chart.
- In the X axis title box, replace the current title with Campground Name and press Enter.
- In the Y axis title box, replace the current title with Range of Plant in Hectares and press Enter.
- If necessary, maximize the ArcGIS Pro window or undock the chart view and resize it so you can see all four campground names.
Data values are labeled on the y-axis. The number of values depends on the size of the chart.
- Hover over a bar on the chart.
Callout text on the chart reports the campground name and the exact summarized area value.
- Click a bar on the chart.
The bar is selected on the chart. The corresponding map feature and table record are also selected. You can select multiple features by dragging your mouse to draw a rectangle through bars on the chart.
- Click some white space on the chart to deselect the bar.
- Close the chart, the table, and the Chart Properties pane.
- On the Quick Access Toolbar, click Save .
View geoprocessing history
ArcGIS Pro saves a detailed record of the geoprocessing tools you have used in the project. This geoprocessing history shows the order in which tools were run and saves the tool parameter settings. In a complex analysis, the geoprocessing history can help you retrace your steps, run tools with different settings to explore alternative outcomes, and alter the workflow, if necessary. You can also use the history to help build a geoprocessing model or to create a geoprocessing package of tools and data that can be shared with others.
- On the ribbon, click the Analysis tab. In the Geoprocessing group, click History .
In the Catalog pane, the Geoprocessing History expands to show the three geoprocessing tools you have run. They appear with green check marks (because they ran successfully) and time stamps.
- Right-click a tool in the Geoprocessing History and click View Details.
A message window shows the parameter settings and other information. You can also right-click the tool in the Geoprocessing History to open it or to run it again with the same parameters.
- Close the message window.
In many analysis situations, different tools or combinations of tools can be used to achieve the same results. In this case, it wasn't strictly necessary to use Select Layer By Location. You could have run Summarize Within directly on the Campground_Buffers layer. Your output feature class would then have had fourteen records instead of four. Ten of those records would have had values of 0 in the Summarized area in HECTARES field. One advantage to using the Select Layer By Location tool is that it provides visual feedback that can reveal spatial patterns and suggest new directions for your analysis.
To go a step farther, you could have replaced the Buffer and Summarize Within tools with Summarize Nearby, which combines the functionality of those two tools. Ultimately, this means you could have obtained your analysis results using one tool instead of three. However, you might have had a less clear understanding of each of the logical parts in this analysis.
To see how the workflow in this tutorial can be modeled and run as a geoprocessing tool, try the Make a geoprocessing model tutorial.
For more advanced analysis projects that involve understanding and comparing places, see How many streetlights and miles of bike route in each district? and Are liquor stores too close to schools, libraries, and parks? in the ArcGIS Desktop analytics case studies.