Map Marin County forests

In this tutorial, you'll add data for counties and land cover in the United States to an ArcGIS Pro project. Then, you'll extract information for your area of interest, Marin County.

Create a Marin County polygon

First, you'll create a polygon layer to show the Marin County boundaries. You'll download United States county data from the ArcGIS Living Atlas of the World and extract the data for Marin County.

The ArcGIS Living Atlas is an online collection of authoritative geographic information from around the world. It contains many ready-to-use data layers, including the political boundary and land cover layers you'll use in this tutorial.

  1. Start ArcGIS Pro. If prompted, sign in using your licensed ArcGIS organizational account.
    Note:

    If you don't have access to ArcGIS Pro or an ArcGIS organizational account, see options for software access.

    When you open ArcGIS Pro, you're given the option to create a new project or open an existing one. If you've created a project before, you'll see a list of recent projects.

  2. Under New Project, click Map.

    Map template

    The Create a New Project window appears.

  3. For Name, type Marin County Smoke Detector Analysis. Click OK.

    The project is created. Next, you'll add data.

  4. On the ribbon, click the Map tab. In the Layer group, click the Add Data button.

    Add Data button

    The Add Data window appears. You can add data from several sources, including ArcGIS Living Atlas.

  5. Under Portal, click Living Atlas.

    Living Atlas option for adding data

  6. In the search box, type USA Census Counties and press Enter. In the list of search results, click USA Census Counties.

    USA Counties layer in search results

  7. Click OK.

    The layer is added to the map. It contains all county and county equivalents in the United States. You only need the data for one county, however. You'll export Marin county to a new feature layer.

  8. On the ribbon, on the Analysis tab, in the Geoprocessing group, click Tools.
    Open the Geoprocessing pane

    The Geoprocessing pane appears.

  9. In the Geoprocessing pane, search for and open the Export Features (Conversion Tools) tool.
    Open the Export Features tool

    The Export Features tool pane opens.

  10. In the Export Features tool pane, set the following parameters:
    • For Input Features, choose dtl_cnty.
    • For Output Name, type Marin_County.
    • Expand the Filter section and input the expression County name is equal to Marin County.

    New expression button

  11. Click Run.

    The tool runs and the new layer is added to the Contents pane. You no longer need the original layer, so you'll remove it.

    Tip:

    To remove a layer, right-click on the layer (dtl_cnty) and choose Remove.

    Next, you'll zoom to Marin County on the map.

  12. In the Contents pane, right-click Marin_County and choose Zoom To Layer.

    The map zooms to Marin County.

    Marin County on the map

  13. On the Quick Access Toolbar, click the Save button.

    Save button

Create a polygon of Marin County forests

Next, you'll map forests in Marin County. You'll add a National Land Cover Database (NLCD) layer from ArcGIS Living Atlas and use a raster function to display only forest land cover. Then, you'll extract a polygon layer representing Marin County's forests.

  1. On the ribbon, on the Map tab, in the Layer group, click the Add Data button. In the Add Data window, under Portal, click Living Atlas.
  2. Search for NLCD. Add the USA NLCD Land Cover layer to the map.

    The layer is added. The NLCD is produced by the Multi-Resolution Land Characteristics Consortium, a group of United States federal agencies that produces land cover information at the national scale.

  3. In the Contents pane, turn off the Marin_County layer.

    Land cover in Marin County

    Marin County has some developed areas (displayed in red) on the county's eastern coast, but a large portion of the county's interior is forest (displayed in green). Next, you'll display only forested areas.

  4. On the ribbon, click the Analysis tab. In the Raster group, click the Raster Functions button.

    Raster Functions button

    The Raster Functions pane appears. Raster functions apply processing operations to raster layers, such as the USA NLCD Land Cover layer. They apply these operations on the fly, which means that no new dataset is created, saving time and storage space.

  5. In the Raster Functions pane, search for Remap. In the list of results, click Remap.

    Remap raster function in list of search results

    Raster layers are composed of cells, and each cell has a value. For instance, in the USA NLCD Land Cover layer, each land cover type has a unique numeric value (which can be found in the layer's metadata). The values for forested land cover types range between 41 and 44.

    The Remap Properties raster function changes cell values based on parameters you choose. You'll remap the USA NLCD Land Cover layer so that all forested land cover values are changed to 1, and all non-forest land cover types are removed.

  6. In the Remap Properties raster function, for Raster, choose USA NLCD Land Cover.
  7. In row 1, for Minimum, type 41, and for Maximum, type 44. For Output, type 1. Check Change unmatched /missing values to NoData.

    Parameters for the Remap Properties raster function

  8. Click Create new layer.

    The Remap_USA NLCD Land Cover layer is added to the map. It displays forested areas with white cells. Non-forested areas have no data and do not draw.

    Your area of interest is Marin County, so you'll clip the dataset to the correct extent.

  9. In the Raster Functions pane, search for and open the Clip raster function. Set the following parameters:

    • For Raster, choose Remap_USA NLCD Land Cover.
    • For Clipping Geometry / Raster, choose Marin_County.
    • Check Use input features for clipping geometry.

    Parameters for the Clip raster function

    You'll also change the output layer name.

  10. Click the General tab. For Name, type Marin County Forest.

    Parameters for the General tab of the Clip raster function

  11. Click Create new layer.

    The Marin County Forest_Remap_USA NLCD Land Cover layer is added to the map. This layer displays all forested cells in black. Next, you'll convert the raster layer to a polygon layer, so that it can be enriched later.

  12. If necessary, on the ribbon, on the Analysis tab, in the Geoprocessing group, click Tools to open the Geoprocessing pane.
  13. In the Geoprocessing pane, search for and open the Raster to Polygon tool.

    Search for Raster to Polygon tool

  14. In the Raster to Polygon tool, set the following parameters:

    • For Input raster, choose Marin County Forest_Remap_USA_NLCD Land Cover.
    • For Output polygon features, change the output name to Marin_County_Forests.
    • Uncheck Simplify polygons.

    Raster to Polygon parameters

  15. Click Run.

    The Marin_County_Forests layer is added to the map. It represents all locations in Marin County where land cover is predominantly forest. However, it may exclude adjacent areas classified as scrub or grassland because they lacked sufficient tree canopy. You'll create a small buffer around the forest polygon to encompass adjacent areas.

  16. In the Geoprocessing pane, click the Back button.

    Back button

  17. Search for and open the Pairwise Buffer tool. Set the following parameters:

    • For Input Features, choose Marin_County_Forests.
    • For Output Feature Class, change the output name to Marin_County_Forested_Area.
    • For Distance, type 30 and choose Meters for the type of unit.
    • For Dissolve Type, choose Dissolve all output features into a single feature.

    Parameters for the Buffer tool

  18. Click Run.

    The tool runs and the layer is added to the map. You've created the forest polygon. Next, you'll remove intermediary layers that you no longer need.

  19. In the Contents pane, remove the following layers:

    • Marin_County_Forests
    • Marin_County
    • Marin County Forest_Remap_USA_NLCD Land Cover
    • Remap_USA NLCD Land Cover
    • USA NLCD Land Cover

    Only the forested area polygon remains.

    Marin County with buffered forested area layer

  20. Save the project.

You have added ArcGIS Living Atlas data for county boundaries and land cover to an ArcGIS Pro project. Then, you extracted a polygon layer of forested area in Marin County.


Map smoke detector adoption

Next, you'll enrich your polygon layer of forested area in Marin County with information about the percentage of households with smoke detectors. County supervisors also want to know where these households are distributed across the county. To show them, you'll create a tessellation of hexagons and enrich them as well. Together, your enriched layers will provide the supervisors with the information they need to create a targeted fire education program for the community.

Enrich the forested area layer

First, you'll enrich the Marin_County_Forested_Area layer to see what percentage of households in high risk areas across the county have smoke detectors.

  1. If necessary, open your Marin County Smoke Detector Analysis project in ArcGIS Pro.
  2. If necessary, open the Geoprocessing pane (or click the Back button if a tool is already open). Search for and open the Enrich tool.

    The Enrich tool determines demographic information for a polygon using the ArcGIS GeoEnrichment Service. The GeoEnrichment Service can be used for over 130 countries, some of which have thousands of demographic and consumer behavior variables for the most recently available annual estimates.

    Note:

    The Enrich tool consumes credits assigned to your ArcGIS account. In this section, you'll enrich one with four fields, which will cost 0.04 credits. In the next section, you'll enrich 463 features with 4 variables for a total cost of 18.63 credits. The ArcGIS Online help topic Understand credits contains more information about credit usage.

  3. For Input Features, choose Marin_County_Forested_Area. For Output feature class, change the output name to Marin_County_Forested_Area_Smoke_Detectors.

    Input and output parameters for the Enrich tool

    Next, you'll change the demographic data source from the default source to a source that specializes in United States data.

  4. Click the Environments tab and click the Browse button.

    Browse button

    The Business Analyst Data Source window appears.

  5. Under Portal, click North America. Under United States, choose Esri 2023, and click OK.

    United States Standard data source

    The data source is updated. Next, you'll choose the demographic variables with which to enrich the area.

  6. Click the Parameters tab. For Variables, click the plus button.

    Plus button

    The Data Browser window appears.

  7. In the search box, type Smoke Detector and press Enter. Under 2023 Household Furnishings & Appliances (Market Potential), check 2023 HH owns smoke/fire detector.
    Note:

    Demographic data is updated periodically. Feel free to choose more recent demographic data if it is available.

    Smoke detector variable

    The data provider, Market Potential, is indicated in parentheses. At the end of the tutorial, you'll add the data source to the map.

    You'll also add variables to contextualize the count of households that own smoke or fire detectors. These variables will include information about people who may be at particular risk during a fire (such as people with asthma or the elderly) and the total number of households.

  8. Search for Asthma. Under 2023 Health (Market Potential), check 2023 Used Asthma Prescription Drug.
  9. In the left pane, under United States (Esri 2023), click Categories. Double-click the Age category.

    Age category

  10. Double-click Age Dependency. Check 2023 Senior Population.
  11. In the left pane, click Categories. Double-click the Households category.
  12. Double-click Household Totals and check 2023 Total Households.

    You have chosen four variables. An indicator in the upper right corner of the window confirms the number.

    Indicator for the total number of variables

  13. Click OK.

    Enrich variables

    All of your selected variables are listed.

  14. In the Geoprocessing pane, click estimate credits.

    Estimate credits

    Running the tool will consume 0.04 credits.

  15. Click Run.

    The tool runs and the Marin_County_Forested_Area_Smoke_Detectors layer is added to the map. You no longer need the original forested area layer.

  16. In the Contents pane, right-click Marin_County_Forested_Area and choose Remove.

    You'll explore the results of enriching the layer with demographic data by opening the layer's pop-up.

  17. If necessary, on the ribbon, on the Map tab, in the Navigate group, click Explore.
  18. On the map, click anywhere inside the result polygon.

    A pop-up appears with information about the polygon's attributes, including the fields with which you enriched the layer.

    Tip:

    You can resize the pop-up to better see all of the fields.

    Pop-up for the Marin_County_Forested_Area_Smoke_Detectors layer

  19. Close the pop-up.
  20. Save the project.

Create and enrich a tessellation

Your results include demographic data for all households in the forested area of Marin County. That information will be useful for providing county supervisors with an overall picture of the region. However, the forested area covers a large amount of space within the county and there is no indication of where households are concentrated.

To map the spatial distribution of the data, you'll create a tessellation. A tessellation divides a polygon into smaller geometric shapes. You'll divide your forested area polygon into hexagons and enrich them with the same demographic variables to better show where the households are located.

  1. In the Geoprocessing pane, click the Back button. Search for and open the Generate Tessellation tool.
  2. In the tool, set the following parameters:

    • For the name of the Output Feature Class, type Marin_Hexagon_Bins.
    • For Extent, click the down arrow for Extent of a Layer and choose Same As layer: Marin_County_Forested_Area_Smoke_Detectors.
    • For Size, type 2 and choose Square US Survey Miles as the unit of measurement.

    Two square miles is the smallest recommended size when using the Enrich tool on a polygon. Smaller polygons will contain less reliable results.

    Parameters for the Generate Tessellation tool

    Note:

    A warning message may appear saying converting areal units in square miles to unknown is not supported. You can ignore the message as it'll not affect the workflow.

  3. Click Run.

    The tool runs and adds the Marin_Hexagon_Bins layer to the map. The layer contains a hexagon grid that covers the entire rectangular extent of Marin County. Many of these hexagons either do not intersect Marin County or contain areas other than forested land. You'll clip the layer to the extent of the forested area polygon.

  4. In the Geoprocessing pane, click the Back button. Search for and open the Pairwise Clip tool.
  5. For Input Features, choose Marin_Hexagon_Bins. For Clip Features, choose Marin_County_Forested_Area_Smoke_Detectors.
  6. Click Run.

    The tool runs (it may take a few minutes) and the layer is added to the map.

  7. In the Contents pane, right-click Marin_Hexagon_Bins and choose Remove.
    Note:

    The default symbology of the layer is random and may differ from the example image.

    Marin County forested area with hexagon bins

    Next, you'll enrich the hexagons with the same demographic variables. Rather than choose the variables again, you can access your geoprocessing history and run the Enrich tool with the same parameters that you used before.

  8. On the ribbon, click the Analysis tab. In the Geoprocessing group, click the History button.

    Geoprocessing History button

  9. Double-click Enrich.

    Enrich tool in geoprocessing history

    The Geoprocessing pane appears, displaying the Enrich tool. All of the parameters you chose the first time you ran the tool are unchanged. You only need to change the input and output parameters. Because you'll enrich more features this time, the tool will consume more credits.

  10. Change Input Features to Marin_Hexagon_B_PairwiseClip. For Output feature class, change the output name to Marin_Hexagon_Bins_Enriched.

    Enrich hexagon bins

  11. Click estimate credits, followed byRun.

    The tool consumes around 9 credits. The tool runs and the layer is added to the map. You no longer need the original hexagon layer.

  12. In the Contents pane, right-click Marin_Hexagon_B_PairwiseClip and choose Remove.
  13. Save the project.

Symbolize the results

You intend to share your results with county officials. You'll symbolize the enriched data so that your findings are intuitive to understand.

  1. In the Contents pane, right-click Marin_Hexagon_Bins_Enriched and choose Symbology.

    The Symbology pane appears. Currently, the hexagons are symbolized with a single color. You'll change the symbology so that hexagons with a higher percentage of houses without smoke detectors have a red or orange color, indicating danger.

  2. In the Symbology pane, for Primary symbology, choose Graduated Colors. For Field, choose 2023 HH Owns Smoke or Fire Detector.

    Primary symbology and Field parameters changed

    Many of the hexagons on the map have no residents. You'll symbolize these hexagons with a different symbol than the rest of the data.

  3. Click the Advanced symbology options tab.

    Advanced symbol options tab

  4. Expand Data exclusion and click the New expression button. Create the expression Where HasData is equal to 0.

    Expression to exclude hexagons with no data

    This expression will create a symbology class for hexagons with no data. Next, you'll adjust the number of classes and color scheme for the hexagons that do have data.

  5. Click Apply. Click the Primary symbology tab.

    Primary symbology tab

  6. For Classes, choose 3.

    The legend updates. It shows five classes total, four for hexagons with data and one for hexagons without data. The values in the legend are the total count of households with smoke detectors. To show the percentage of households, you'll normalize the data by the total number of households.

  7. In the Primary symbology tab, for Normalization, choose 2023 Total Households.

    The legend updates. The classes show values from 0 to 1, which correspond to percentages. Currently, the range of values for each class is determined by statistical trends in the data. You'll change the values to easily understandable intervals.

  8. In the Symbology pane, in the Classes tab, for the first class, double-click the cell in the Upper value column, type 0.5, and press Enter.

    Upper value for the second row

  9. Change the upper value for the second row to 0.75.

    You'll also update the labels for each class so that they are expressed as percentages.

  10. Change the first label, change to under 50%, the second to 50 - 75%, the third to over 75%, and the forth to No residents.

    Edit the labels

    Last, you'll change the colors. First, you'll change the color ramp for the graduated colors. Then, you'll change the color for the excluded class.

  11. For Color scheme, expand the dropdown list and check Show names. Then choose the Yellow-Orange-Red (3 Classes) color scheme.

    Yellow-Orange-Red color scheme

    You'll reverse the symbol order so that the lowest percentages (the places with fewer smoke detectors) have the darkest colors.

  12. Right-click the Symbol column heading and choose Reverse symbol order.

    Reverse symbol order option

  13. Click the symbol in the first column of the excluded class.

    Excluded symbol

  14. In the Format Polygon Symbol pane, click the Properties tab. For Color, choose Sage Dust (7th column, 7th row), and for Outline color, choose Lotus Pond Green (7th column, 10th row).

    Color and Outline color parameters for the excluded class

  15. Click Apply and close the Symbology pane. In the Contents pane, turn off the Marin_County_Forested_Area_Smoke_Detectors layer.

    The color for hexagons with no data is updated in the legend and on the map.

    Marin County with hexagons symbolized

    Most hexagons either have no residents or 50.1 to 75.0 percent smoke detector ownership. Only a few have ownership levels under 50 percent, and very few have no smoke detector ownership. There were no residents that had 0 percent values. But also keep in mind some of the areas had no data which you excluded out. You'll look at some of the under 50% percent ownership hexagons to learn more.

  16. On the map, click any red hexagon.

    Its pop-up appears. Almost all of the red hexagons have extremely low numbers of total households. Most have only one household, which does not have a smoke detector. While it's not necessary to explain this trend on the map, there are two potential factors for why hexagon bins may have such low counts of households.

    The first factor is that the Enrich tool uses the United States Census Bureau's Block Point Centroids as the basis to apportion variables. In rural areas, there are usually more residences than block points, so the Enrich tool may omit some residences.

    The second factor is that the United States Census Bureau does not publish small counts of people to protect privacy. Some hexagons with few or no residences may actually have some residents, but the data is not publicly available.

    Because of these factors, small counts in Enrich results for rural areas may not be exact.

  17. Close the pop-up.

Format the data

You'll finish your work by hiding unneeded fields from the data and citing the data source.

  1. In the Contents pane, right-click Marin_Hexagon_Bins_Enriched and choose Attribute Table.

    The table contains several fields that are not of interest to county officials.

  2. Right-click the heading of each of the following fields and choose Hide Field:

    • OBJECTID
    • GRID_ID
    • aggregationMethod
    • ORIGINAL_OID
    • sourceCounty
    • apportionmentConfidence
    • populationToPolygonSizeRating
    • Shape_Length
    • Shape_Area

    Attribute table with hidden fields

  3. Close the attribute table. Open the attribute table for the Marin_County_Forest_Area_Smoke_Detectors layer and hide the following fields:

    • OBJECTID
    • aggregationMethod
    • ORIGINAL_OID
    • sourceCounty
    • apportionmentConfidence
    • populationToPolygonSizeRating
    • Shape_Length
    • Shape_Area

  4. Close the attribute table.

    Next, you'll rename the layers to be more meaningful.

  5. In the Contents pane, double-click Marin_Hexagon_Bins_Enriched. In the Layer Properties window, on the General tab, change Name to Marin County Forested Area Smoke Detector Adoption Rate and click OK.
  6. Open the Layer Properties window for the Marin_County_Forested_Area_Smoke_Detectors layer, change Name to Marin County Total Forested Area Smoke Detector Adoption Rate, and click OK.

    Last, you'll cite the data sources for variables provided by the Enrich tool.

    Tip:

    You can find the source for all demographic data used by Esri services on the Esri Demographics documentation page. To find a specific data source, click the Data tab and navigate to the appropriate section based on the data's geography. For instance, to find the source of the data used in this tutorial, you would expand the United States section, click Market Potential, and scroll to Methodology. Then, access the 2023 Esri Market Potential Methodology Statement documentation. The data source listed is the MRI Survey of the American Consumer, 2022 Doublebase® from MRI-Simmons.

  7. In the Contents pane, right-click the Marin County Forested Area Smoke Detector Adoption Rate, and choose Properties. In the Layer Properties window, on the Metadata tab, for Show metadata from data source (read-only), choose Layer has its own metadata.

    Layer has its own metadata option

  8. For Credits, paste the following text:

    Esri 2023 Market Potential data derived from MRI Survey of the American Consumer, 2022 Doublebase® from MRI-Simmons.

    Credits text

  9. Click OK.
  10. Open the Layer Properties window for the Marin County Total Forested Area Smoke Detector Adoption Rate layer. On the Metadata tab, choose Layer has its own metadata and add the same citation to the Credits box.
  11. Click OK. Save the project.

In this tutorial, you provided Marin County supervisors with insight about residential adoption of smoke detectors within the county's forested areas. You accomplished this task with ArcGIS Pro, ArcGIS Living Atlas of the World, and ArcGIS GeoEnrichment Service. Your analysis relied on authoritative data that you presented with intuitive symbology to help inform county officials.

The results of your analysis can be made available by sharing it as an ArcGIS Pro project package. Alternatively, it can be shared as an interactive web map that officials can explore.

You can find more tutorials in the tutorial gallery.