Solve a spatial problem
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Access the data
You'll start by opening the Nassella Tussock Range map in Map Viewer.
- Go to the Nassella Tussock Range map.
The map shows the Marlborough region of New Zealand. Commercial campgrounds are displayed, along with the known distribution of Nassella tussock. 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.
- On the ribbon, click Sign In. Sign in to your ArcGIS organizational account.
Note:
If you don't have an organizational account, see options for software access.
You'll save a copy of the map before you make any changes.
- On the Contents (dark) toolbar, click Save and open and choose Save as.
Note:
At the bottom of each toolbar, you can click the Expand button to display the name of the button, rather than just the icon. The steps in this tutorial show the toolbars expanded.
- Rename the map Nassella Tussock Analysis.
- Click Save.
Explore the tools
To perform the analysis, you'll run tools from the Analysis pane. First, you'll see how these tools are organized in Map Viewer.
- On the Settings (light) toolbar, click Analysis.
Note:
If you do not see the Analysis button in Map Viewer, contact your ArcGIS administrator. You may not have the privileges required to perform analysis. Learn more about licensing requirements for spatial analysis.
The Analysis pane appears. From the Home tab, you can access other tabs, like the Tools or History tabs. The Tools tab lists all available analysis tools and the History tab tracks which spatial analysis tools have been run in a web map, including successful and unsuccessful runs.
- Click Tools.
The tools are grouped into categories based on the type of analysis they perform. The Summarize data tools are displayed by default.
- Point to the Summarize Nearby tool.
A tooltip provides a description of the tool.
The Summarize Nearby tool calculates statistics for features within a specified distance of other features. You'll use it to calculate how much Nassella tussock lies near campgrounds.
Quantify tussock near campgrounds
You want to find out how much Nassella tussock lies near campgrounds. Why does that matter? For public education, it may 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.
- In the Tools pane, click the Summarize Nearby tool.
One of the functions of this tool is to calculate how much area from one layer falls within a distance of another layer—this is what you want to do for your analysis. The first parameter determines the features that will be summarized. The second parameter determines the feature around which the distance will be calculated.
- In the Summarize Nearby tool, enter the following parameters:
- For Input features, click Layer and choose Nassella Tussock Range.
- For Nearby layer, click Layer and choose Commercial Campgrounds.
- For Measurement type, ensure Line distance is selected.
- For Measurement values, type 1.5 and press Enter.
- For Units, choose Kilometers.
- Ensure Return output as bounding areas is checked.
You can also choose to calculate statistics for the input layer. In this case, you'll summarize the area of Nassella tussock that is found within 1.5 kilometers of each campground.
- In the Calculate statistics group, ensure Include summarized geometry of features is enabled.
- Change Summarized area units to Hectares.
A hectare is a metric unit of area equal to 10,000 square meters or roughly two and a half acres.
- In the Result layer group,
change Output name to Tussock Near Campgrounds, followed by your name or initials.
Note:
You cannot create two layers in an ArcGIS organization with the same name. Adding your initials to a layer name ensures that other people in your organization can also complete this tutorial. Once a layer has been created, you can rename it in the map to remove your initials, which will not affect the name of the underlying data layer.
- Click Estimate credits.
The tool will use 2.419 credits. The number of credits is based on the number of features to be processed.
- Click Run.
When the tool completes successfully, the Tussock Near Campgrounds layer appears on the map.
The features are symbolized with graduated colors, showing campgrounds with the least Nassella tussock in beige and campgrounds with the most Nassella tussock in dark purple.
Update the map symbols
You ran the Summarize Nearby tool to calculate the total area containing Nassella tussock plants within 1.5 kilometers of a campground. Next, you'll update the symbol style and filter the results.
- If necessary, in the Layers pane, click the Tussock Near Campgrounds layer to select it.
- On the Settings toolbar, click Properties.
- In the Properties pane, in the Appearance section, for Transparency, drag the slider all the way to left to set it to 0.
- On the Settings toolbar, click Effects.
- In the Effects pane, click Drop shadow to enable it.
All the campground summaries are symbolized, but you know from viewing the Nassella Tussock Range layer that the campgrounds don't all have Nassella tussock growing near them. You'll filter the layer to show only campgrounds with the invasive weed.
- On the Settings toolbar, click the Filter button.
- In the Filter pane, click Add new.
- For Condition, click the Name drop-down menu and choose Summarized Area in Hectares.
- Click the second drop-down menu and choose is greater than.
- For the box containing the numeric value, delete the existing number and type 0.
The full expression now reads Summarized Area in Hectares is greater than 0.
- Click Save.
The beige features are removed from the map. You'll also turn off the Commercial Campgrounds layer.
- In the Layers pane, point to Commercial Campgrounds and click the Hide Commercial Campgrounds button.
The campground locations are removed from the map.
- In the Layers pane, for Tussock Near Campgrounds, click the Options button and choose Show table.
The table appears, showing the records for the layer.
Because you set a filter on the layer, only the four campgrounds with Nassella tussock are shown.
Note:
If more than four records are shown in the table, it may mean the Filter pane has reopened. Click Save or close the filter pane to view the table with the filter applied.
The Summarized area in Hectares field shows the total area of Nassella tussock within each campground range. The largest area of Nassella tussock is at the Awatere Settlers Motor Camp, where there are more than 83 hectares. The smallest area of Nassella tussock overlaps the Blenheim TOP 10 Holiday Park and has approximately 0.25 hectares. Keep in mind that the Nassella Tussock Range layer represents areas in which the plant has been found, not the actual plant density.
- Close the table.
Visualize analysis results
Next, you'll showcase the results of the analysis using a bar chart.
- If necessary, in the Layers pane, click the Tussock Near Campgrounds layer to select it.
- On the Settings toolbar, click Configure charts.
- In the Charts pane, click Add chart and choose Bar chart.
The Data pane appears.
- For Category, choose Name.
The chart updates to show the campground name on the x-axis and the count of features on the y-axis. You'll update the chart so it uses the summarized area of Nassella tussock on the y-axis.
- For Numeric fields, click Select numeric fields and choose Summarized Area in Hectares.
- Click Done.
The bar chart updates to show the total area of Nassella tussock near each campground.
- In the Data pane, enable Show data labels.
The labels appear on top of each bar.
- Click the Series tab.
The Series tab includes configurations for multiple series and the chart style.
- Under Series, click Summarized Area in Hectares.
The Series style pane appears.
- For Symbol color, enter the hex value B966BD. Close the Series style pane.
- Click the Axes tab.
The Axes tab includes configurations for the x-axis and y-axis.
The default character limit for the x-axis labels is 11, which is lower than the number of characters in all of the campground names. You'll increase the limit so the full names are displayed.
- Under X-axis, for Label character limit, type 30.
The x-axis updates to display the full campground names.
You'll also update the configuration for decimal places in y-axis labels.
- Under Y-axis, for Decimal places, type 2.
Now, fewer decimal places display for the numeric values. The chart is currently showing the default title and axis labels. You'll update them to something more informative.
- Click the General tab.
The General tab includes configurations for the titles and legends on the chart.
- For Chart title, replace the default title with Nassella Tussock Near Commercial Campgrounds.
The chart title updates.
- Update the axis titles as follows:
- For X-axis title, type Campground name.
- For Y-axis title, type Range of plant in hectares.
- Save the map.
In this tutorial, you found publicly available data, calculated the total area of Nassella tussock within each campground range, and displayed the results in a bar chart. What's next? You can perform a similar analysis to solve the Nassella tussock problem using the geoprocessing tools in ArcGIS Pro.
You can find more tutorials in the tutorial gallery.
