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Map homelessness by state

In the previous lesson, you published a layer of the United States with data on total population, homeless population, and change in homeless population. In this lesson, you will use that layer to create three web maps of the United States.

Start a new map

Your first map will show the total number of homeless people per state. From looking at the data, you know North Dakota has a relatively low total number of homeless, so this map will probably not help your cause. However, because it is such a fundamental statistic, you must show it.

  1. Sign in to your ArcGIS organizational account.
  2. At the top of your organization's home page, click Content.

    Content

    The My Content tab on the content page includes two new items titled Homelessness_YourName. One is a service definition that contains the actual data and drawing specifications for your published service, while the other is a feature layer that you can add to a map. You will work with the feature layer.

  3. Click the browse button next to the Homelessness_YourName feature layer and choose Add to new map.

    Add to new map option on the feature layer menu

    A new map containing the layer appears.

  4. Zoom in until the extent roughly corresponds with the contiguous 48 states.

    Next, you will rename the layer to reflect the data this map will show.

  5. If necessary, close the Change Style pane (click Cancel).
  6. In the Contents pane, point to the Homelessness YourName layer. Click the More Options button and choose Rename.

    Rename in the More Options menu

  7. Rename the layer Homeless Counts and click OK.

Symbolize the layer by homeless population

Next, you will symbolize the number of homeless by drawing a circle within each state. The size of the circle will vary depending on the attribute value. Using graduated symbols instead of colors helps the user compare symbols to one another independently of the areal boundaries of the states. It also avoids creating the impression that homeless people are evenly dispersed throughout each state.

  1. Under the Homeless Counts layer, click the Change Style button.

    Change Style button

  2. In the Change Style pane, for Choose an attribute to show, choose Homeless Count (2013).

    Choose an attribute to show set to Homeless Count (2013)

    The pane updates to show the ways the attribute can be symbolized.

  3. Under Counts and Amounts (Size), click Select.

    Select button for Counts and Amounts (Size)

    On the map, each state is symbolized with an orange circle that changes size depending on the state's homeless population.

    Map symbolized with orange circles using Counts and Amounts (Size)

  4. Under Counts and Amounts (Size), click Options.

    The Change Style pane changes to show the options. You can adjust symbol size, color, and more.

  5. Under Size, check Classify Data.

    Classify Data check box under Size options

    Classify Data uses a mathematical formula to determine the values at which symbols change size on the map, also known as breaks. The default classification scheme is Natural Breaks, which uses large differences between groups of values to set breaks.

  6. Under Classify Data, change the number of classes to 5.

    Classify Data with 5 classes

    The number of classes determines the number of breaks in the data. When you change the classes, the symbols on the map update automatically. Many of the symbols are unnecessarily large and cover smaller symbols, so next you will change the maximum and minimum symbol sizes.

  7. Under Size, change Min to 8 pixels and Max to 24 pixels.

    Min size set to 8 pixels and max size set to 24 pixels

    You can also change the symbol color.

  8. Click Symbols.

    Symbols

    A window appears with additional symbology options.

  9. At the top of the window, click Fill. On the color palette, click the fourth dark blue from the top.

    Blue color #005CE6 selected

  10. At the top of the window, click Outline. On the color palette, click the fifth dark blue from the top.

    Blue color #004DA8 selected

  11. Change Line Width to 2 pixels.

    Line Width slider set to 2 pixels

  12. Click OK. At the bottom of the Change Style pane, click OK and click Done.

    Part of the map showing blue circle symbols on each state

    Note:

    The size of the symbols remains the same when you zoom in and out. Your symbols may appear larger or smaller relative to the state boundaries depending on your extent. You can change the symbol sizes in the Change Symbol window.

    On the map, you can see that North Dakota and many of the rural plains states have small homeless populations compared to the more urbanized states such as Illinois and New York. The default Topographic basemap is better suited for a reference map (which emphasizes the geographic location of features) than a thematic map (which focuses on a specific theme, such as homelessness). Next, you will change the basemap to something simpler.

  13. On the ribbon, click Basemap and choose Light Gray Canvas.

    Light Gray Canvas in the Basemap gallery

    The basemap changes.

    Part of the map with blue circles in each state and a light gray basemap

    The map gives a generalized visual representation of the data but not exact numbers. The exact counts are accessible through pop-ups, so when users click a state, they can see how many homeless people live there.

Configure pop-ups for the homeless population map

When you were preparing your data in ArcGIS Pro, you reset the configuration of the pop-ups to show a feature’s attribute information. You can further customize pop-ups to only show the information relevant to the map.

  1. On the map, click North Dakota.

    Pop-up for North Dakota showing all attributes

    The default pop-up appears. It displays all of the attributes. The pop-up could be better, however. First, this map is only about homeless counts, but other attributes are also visible. Second, the state name is displayed twice. Third, the attribute values for population and count are not easy to read.

  2. Close the pop-up. In the More Options menu of the Homeless Counts layer, click Configure Pop-up.
  3. In the Pop-up Properties pane, confirm that Pop-up Title is set to {L0USA_States_Generalized_STATE_}. If it is not, click the Add Field Name button next to the text box and choose State {L0USA_States_Generalized_STATE_}.

    Add Field Name button next to Pop-up Title

    A field name in braces is substituted with the attribute for that field when a feature is clicked. For instance, when you click North Dakota, the pop-up will display North Dakota as the title.

  4. Under Pop-up Contents, click Configure Attributes.

    Configure Attributes link beneath pop-up attributes list

  5. In the Configure Attributes window, uncheck the boxes in the Display column next to all fields except Homeless Count (2013).

    Check Display only for Homeless Count (2013)

    Now, only Homeless Count (2013) will be displayed in the pop-up.

  6. Click OK. In the Configure Pop-up pane, click OK.
  7. On the map, click North Dakota (or any state) to view the pop-up.

    Pop-up for North Dakota showing only Homeless count

    Your pop-up shows only the information that this map is supposed to show.

  8. Close the pop-up. On the ribbon, click Save and choose Save As.

    Save as

  9. In the Save Map window, type the following information:
    • TitleNumber of Homeless, 2013
    • Tagshomelessnesshomeless counts, United States2013 (you can add additional tags)
    • SummaryMap of homeless counts by state in the United States

    Tip:

    When entering tags, press Enter after each tag to enter it as an individual tag. Alternatively, type all of the tags separated by commas and press Enter.

    Save Map as Number of Homeless, 2013

  10. Click Save Map.
  11. On the ribbon, click Share.
  12. In the Share window, check Everyone and click Done. (You may need to scroll down to find the Done button.)
    Tip:

    If you are prompted to update the sharing properties of the layers, click Update sharing.

Symbolize the layer by homeless percentage

Although the total number of homeless people in North Dakota is fairly small, that does not mean the problem is less severe for its scale. A state with nearly 40 million people, such as California, is going to have more homeless people than a state with almost 800,000 people, such as North Dakota. But the state with more people will also have more resources to handle the problem. To make your audience see more than homeless counts, your next map will normalize counts by population to show what percentage of a state's population is homeless.

Since your second map will be similar to your first, you will start by making a copy of your first map.

  1. In the Number of Homeless, 2013 map, click Save and choose Save As.
  2. In the Save Map window, edit the following fields:
    • Title: Type Homeless as Percentage of Population, 2013.
    • Tags: Replace the homeless counts tag with homeless percentages.
    • Summary: Replace homeless counts with homeless percentages.

    Save Map as Homeless as Percentage of Population, 2013

  3. Click Save Map.

    The map title changes. You can now make and save edits to the map without affecting your first map. As with your previous map, you will change this map's symbology and configure its pop-ups to show the relevant data.

  4. Rename the Homeless Counts layer Homeless Percentages.
  5. Under the Homeless Percentages layer, click the Change Style button.

    In your previous map, you used graduated symbols to represent the count of homeless people. One reason you did not use color shading was that you did not want to suggest that homeless people were evenly distributed throughout each state. Now that you are dealing with a ratio, that consideration does not apply.

  6. Under Choose an attribute to show, choose Homeless per 10,000.
  7. Under Select a drawing style, select Counts and Amounts (Color) and click Options.

    Counts and Amounts (Color)

  8. In the symbology options, click Symbols.

    Symbols

    Since you are symbolizing by color instead of size, the symbols window has several color ranges for you to choose from.

  9. Click the last color range, red to yellow, and click OK.

    Red to yellow color scheme

    The map updates with the new colors.

  10. As you did in the previous map, check Classify Data and change the number of classes to 5.

    Map with red to yellow color scheme showing North Dakota as dark orange

    This map does not seem to show the problem in North Dakota, either. North Dakota is in a middling class, while a small number of outliers take up the higher classes. However, unlike the previous map, the problem is not that North Dakota has a low value; in fact, it has one of the highest values in the country. The problem is that the class breaks between categories are skewed by three or four exceptionally high values.

    The Natural Breaks classification method is useful for showing outliers, but your goal is to show that North Dakota is in the top percentage of states.

  11. Under Classify Data, change Using to Quantile.

    Classify data using quantile with five classes

    Quantile determines class breaks by distributing an equal number of values into each class. Since your data has 51 features (all states plus the District of Columbia) and you are using five classes, each class has roughly 10 features.

    Map with red to yellow color scheme, showing North Dakota as dark red

    North Dakota is in the highest class, which consists of the 10 states with the highest homelessness rates.

  12. At the bottom of the Change Style pane, click OK and click Done.

Configure pop-ups for the homeless percentage map

Next, you will configure pop-ups for the map. Since the Homeless per 10,000 attribute does not have a self-explanatory title, you will configure a custom attribute display that better explains the data.

  1. In the Contents pane, in the More Options menu of the Homeless Percentages layer, click Configure Pop-up.
  2. Under Pop-up Contents, change Display to A custom attribute display.

    Configure a custom attribute display

  3. Click Configure. In the Custom Attribute Display window, type or copy and paste the following: In 2013, {L0USA_States_Generalized_STATE_} had {HomelessPer10000} homeless people for every 10,000 people.
    Tip:

    If your pasted text has a font or styling that you do not like, you can select it and click the Remove Format button.

  4. Use the Bold button to add bold formatting to {HomelessPer10000}. (Ensure that you include the braces.)

    The Bold button on the Pop-up configure window

  5. Click OK. In the Configure Pop-up pane, click OK.
  6. On the map, click North Dakota (or any state) to view the pop-up.

    Pop-up for North Dakota

  7. Close the pop-up.
  8. Save and share the map with everyone.

    With your second map, more of the story comes into focus. Although North Dakota has a low homeless count, that count is relatively high for its population. However, there are still states that have both higher counts and higher percentages, such as California and New York. To finish the picture of homelessness in North Dakota, you will create one more map: change.

Symbolize the layer by homeless change

Change plays an important role in determining the severity of homelessness in a state. A state with low or negative change, even if it has high homeless counts and percentages, will likely have enough shelters and resources from previous years to deal with the problem. A state with high change, however, may not have such infrastructure, exacerbating homeless conditions. Your last map will depict change in homeless counts from 2012 to 2013.

  1. In your Homeless as Percentage of Population, 2013 map, click Save and choose Save As.
  2. In the Save Map window, edit the following fields. When you finish, click Save Map.
    • Title: Type Percent Change in Homeless Counts, 2012-13.
    • Tags: Replace the homeless percentages tag with homeless change.
    • Summary: Replace homeless percentages with homeless change.

    Save Map as Percent Change in Homeless Counts, 2012-13

  3. In the Contents pane, rename the Homeless Percentages layer Homeless Change.

    The original Homeless Data Excel sheet expressed change data as percentages, but when you viewed that data in ArcGIS Pro, it was formatted with fractions, so 200.7% was written as 2.007. You will multiply those fractions by 100 to convert them to percentages.

  4. Under the Homeless Change layer, click the Show Table button.
  5. On the right side of the table, click the add button and turn on Homeless Change (2012-13). Turn off Homeless Count (2013).

    Show/Hide Columns list with Homeless Change and Homeless Count

  6. Click the header of the Homeless Change (2012-13) column and choose Calculate.
  7. For language, choose SQL.
  8. In the Expression Builder, copy and paste the expression Sheet1__Change * 100.

    Expression

  9. Click Calculate. Confirm that the values were updated in the Homeless Change field. They should now range between -47.44 and 200.73. Close the table.
  10. In the Contents pane, under the Homeless Change layer, click the Change Style button.
  11. In the Change Style pane, under Choose an attribute to show, choose Homeless Change (2012-13). Under Counts and Amounts (Color), click Options.

    Counts and Amounts (Color)

    For the classification scheme, you will use Natural Breaks instead of Quantile to emphasize the fact that North Dakota had an exceptionally high change. You will also increase the number of classes to show that despite the large variation between states, North Dakota still stands out.

  12. Check Classify Data. Change the number of classes to 7.

    Classify Data using Natural Breaks with 7 classes

    Some states have had declines in homeless count, while others have had increases. To show this difference, you will use a diverging color scheme.

  13. Click Symbols. In the list of color ranges, in the second row from the bottom, choose the diverging green and purple color scheme.

    Green to purple color scheme

  14. Click OK. At the bottom of the Change Style pane, click OK and click Done.

    Map with green to purple color scheme showing North Dakota as dark green

    In this map, green states experienced increased homeless counts, while purple states experienced decreased homeless counts. The white states had relatively little change either way. North Dakota is the only state in the highest class. This will be your most persuasive map for informing your audience of the homeless problem in North Dakota.

Configure pop-ups for the homeless change map

You will now configure a pop-up to display the values.

  1. In the More Options menu of the Homeless Change layer, click Configure Pop-up.
  2. In the Pop-up Properties pane, under Pop-up Contents, click Configure to open the Custom Attribute Display window.
  3. Clear the existing text. Type or copy and paste the following: Between 2012 and 2013, {L0USA_States_Generalized_STATE_} experienced a {Sheet1__Change} percent change in homeless counts.
  4. Use the Bold button to add bold formatting to {Sheet1__Change}.

    Pop-up configure window

  5. Click OK. In the Configure Pop-up pane, click OK.
  6. On the map, click North Dakota (or any state) to view the pop-up.

    Pop-up for North Dakota describing 200.73 percent change in homeless counts

  7. Close the pop-up.
  8. Save and share the map with everyone.

In this lesson, you used your layer to create three maps of the United States, each focusing on a different aspect of homelessness. In the next lesson, you will share your results by creating a web app to allow your audience to compare all three maps side by side.