Create a map

Download data shared to a group

Your intern created a CSV file with information about general acute care hospitals in Clark County, Nevada. She shared the data with a public group in ArcGIS Online and sent you a link to the group. This way, you can easily access the data and see other related items she's shared with the group.

  1. Go to the ArcGIS Online Quick Lessons group.
  2. Download the Clark County Hospitals CSV file to your computer and open it.

    You see a table with columns of longitude, latitude, cases, name, cost, and so on. It's hard to visualize where these hospitals are located or any patterns in the information. Making a map is a better way to understand your data than viewing it as a table, so that's your next task.

  3. Close the CSV file.

Add a data layer to a new map and start visualizing patterns

Web map layers are the way geographic data is organized and combined to create maps. These layers are also the basis for geographic analysis. Seeing location-based information on a map is the foundation of understanding and making decisions. You can create a web map layer by adding your CSV file to a new map.

  1. Sign in to your ArcGIS Online organizational account.

    If you haven't joined an organization and don't have an account yet, you can sign up for a free trial.

  2. At the top of the ArcGIS Online website, click Map.
  3. In Map Viewer, on the ribbon, click Add and choose Add Layer from File.

    Add Layer from File selected in the Add menu

  4. Browse to the file you saved to your computer and click Import Layer.

    Data visualized on the map with a legend

    Map Viewer reads the geographic information in your file and displays the data so you can immediately see patterns. For example, you see different-sized circles and a legend that tells you the circles represent total cases in 2015. The larger the circle, the more patients that hospital admitted.

    You also have quick access to the rest of your data by viewing pop-ups.

  5. Click any circle in the map to see the information from your dataset.

    Pop-up with information for Mountain View Hospital

Change the basemap and layer style

The default Topographic basemap is better suited for a reference map than a thematic map. You'll change the basemap to something simpler.

  1. Click Basemap and choose Light Gray Canvas.

    Light Gray Canvas selected in the Basemap gallery

    That's better, but you want the circles to stand out even more so you'll change the style by choosing a different color for your symbols.

  2. In the Change Style pane, for Counts and Amounts (Size), click Options.
  3. Click Symbols. For Fill, choose a medium blue color (such as #0070FF). For Outline, change Transparency to 0%.
  4. Click OK twice.

    Map with updated basemap and layer style

  5. Click Done to finish changing the style of your layer.

Configure pop-ups and view a table

The pop-up that you viewed earlier displayed unnecessary information that you can remove by configuring pop-ups. You want to show only the name of the hospital and the number of total cases.

  1. In the Contents pane, point to the Clark County Hospital layer, click the More Options button, and choose Configure Pop-up.

    Configure Pop-up selected in the More Options menu for the layer

  2. Delete the text in the Pop-up Title field. For Pop-up Contents, change Display to A custom attribute display and click Configure.
  3. In the Custom Attribute Display window, click the Add field name button and choose {Name}. Type admitted with a space before and after it.
  4. Add another field name, {Total_cases_in_2015}, and type patients in 2015. Add bold formatting to the two field names.

    Custom Attribute Display window with the phrase {Name} admitted {Total_cases_in_2015} patients in 2015

  5. Click OK and click OK again to save your changes.
  6. Click a circle in the map to see your revised pop-up.

    Updated pop-up showing custom attribute display

    Don't worry, you haven't lost your data. You can still see it by showing a table.

  7. In the Contents pane, point to the Clark County Hospitals layer, click the Show Table button, and review your data.

    Show Table button

Save the map and update the item details

Your map now tells a story about the location and size of hospitals in Clark County. For example, the hospital with the largest caseload in 2015 is located in Winchester, an unincorporated township that contains the Las Vegas strip. The hospital with the smallest caseload is in Boulder City about 26 miles away. You assume these size differences reflect relative population density in those places, but you'll want to add some demographic data to your map to verify that. For now, you'll save your map so you can share it with your editor when you present your story.

  1. On the ribbon, click Save and choose Save.
  2. In the Save Map window, provide a title, tags, and a summary. Click Save Map.

    If you're signed in with an organizational account and your organization has set up content categories, you can also select up to 20 categories to help others find your map. When assigning categories, you can use the Filter categories box to narrow the list.

    By saving your map, you also created a corresponding item page that contains a variety of information, actions, options, and settings.

  3. In the Contents pane, click the About button. Click More Details to open the item page.

    About button selected with arrow pointing to More Details link

    Your map's item page opens in a new window. The item details are missing important attribution and descriptive information that you should fill in before you share the map. For example, you should give credit to the data providers.

  4. Next to Credits (Attribution), click Edit and type Nevada Department of Health and Human Services, Center for Health Information Analysis (CHIA). Click Save.
  5. Close the item page.

Share the map

Eventually you'll want to share the map with your editor as part of your presentation, but it's not quite ready for that yet. You need to do some more work on it until a newsworthy story emerges. In the meantime, you want to share the map with your intern and one of your colleagues so that they can see what you've done so far and provide feedback on what to explore next.

The fastest way to share a map is to share it with everyone and send an email that includes a link to your map. In the future, you could also embed the map in your newspaper's website and create a web app including a story map with additional text, videos, images, and web pages to enhance your map.

  1. In Map Viewer, click Share.
  2. In the Share window, check the Everyone (public) box. Copy the link to the map so you can paste it into an email to share with others.
  3. Click Done.

Your intern was right. In less than 20 minutes, you created a map with ArcGIS Online and have ideas to share and explore for your story about hospitals in Clark County. What's next?

You can explore ArcGIS Online on your own and discover what else is possible. A few ideas are listed below. Some require an organizational account with publishing or administrative privileges and may consume credits.

  • Browse ArcGIS Living Atlas of the World (a collection of curated geographic data from around the globe) and add demographic data to your map. Answer questions such as Is there more to the obvious difference in the number of caseloads than simple relative population density?
  • Perform spatial analysis on your data to analyze additional patterns such as density of hospitals in Clark County. Answer questions such as Are there any areas where hospital capacity is too low to meet demand?
  • Choose an app to share your map.

You can find more lessons in the Learn ArcGIS Lesson Gallery.