Assignment 5

Geoprocessing emergency rooms, walking to Taco Bell

Use ArcGIS Online to perform spatial analysis. Map the population of Baton Rouge, then create an app to analyze how many people live within 5 minutes of a hospital. The app will allow you to add different layers to analyze: how many people live within a 5-minute walk of a Taco Bell, 15-minute drive of a library, etc.

Table of Contents

• Finished Example
• Data
  • Population layer
  • Example layer: Hospitals
• Steps
  • Part 1: Create a map
  • Part 2. Create an app
  • Part 3: Run analysis
• Try It
• Checklist
• Submit

Finished Example

Screenshot of an app that uses the Analysis Widget, which requires users to sign into ArcGIS Online.

Data

This assignment uses feature layers already hosted in ArcGIS Online. Your app will use the population layer below, but in the Try It section you will run an analysis on a layer you find. Keep in mind that for layers to work with the analysis tools in this exercise:

• Only use point layers of the type “Feature Layer (hosted)”; no tile layers.
• Avoid layers with too many features (hundreds), which could consume too many credits to analyze.

Population layer

Title: USA Census Block Points
Geometry type: Points
Summary: Centroids of census blocks including 2020 population. This layer provides population data as points so the layer can be used in the “Summarize Within” tool to count population within a polygon.
Item Details:: https://arcg.is/erSWG
Service URL: https://services.arcgis.com/P3ePLMYs2RVChkJx/arcgis/rest/services/USA_Census_Block_Points/FeatureServer

Example layer: Hospitals

Title: Baton Rouge MSA Emergency Rooms 2020
Geometry type: Points
Summary: Hospitals offering emergency services in the Baton Rouge Metropolitan Statistical Area as of March 2020.
Service URL: https://services2.arcgis.com/njxlOVQKvDzk10uN/arcgis/rest/services/Baton%20Rouge%20MSA%20Emergency%20Rooms%202020/FeatureServer

Steps

Part 1: Create a map

1. Go to the ArcGIS Online Map Viewer to create and save a new map called “Travel Area Calculator”.
2. In the map viewer, click Add > Add Layer from URL, paste the service URL for the Population layer.
3. Click the newly added USA Census Block Points in the layer list, and then on the right side of the map viewer click the Filter icon to filter the points for LA.
4. Hide the population layer. It doesn’t need to be visible to use its population data in our analysis.
5. Change the basemap if desired.
6. Save the map and share it with Everyone.
7. Click Create and app > Experience Builder.

Part 2: Create an app

1. You should now see Experience Builder. Choose the “Foldable” template, or experiment with others as long as they allow you to add the analysis widget.
   
2. Your map should appear in Experience Builder. If not, you can add it manually.
3. Add widgets to your app by clicking + in the top left, then search for Add Data and Analysis widgets, dragging each one to the map area.
4. Once a widget is added to the map, its window size and position can be adjusted. Clicking the widget will show its options in the right side pane.
   • Add data - default options
   • Analysis - under Add tools, click Spatial analysis tool, search for and click (configure both to allow export and allow adding to the map) Generate Travel Areas and Summarize Within (see Perform Analysis for details on available tools).
5. Save your app and continue to customize the app however you see fit, saving often and previewing as needed.
6. Publish the app when ready and share with Everyone (Public).

Part 3: Run analysis

1. Launch your app, click the Add Data widget, go to the URL tab, and paste the service URL of the Baton Rouge MSA Emergency Rooms layer. Click the Actions icon (four circles) and add it to the map.
2. Now open the Analysis widget. Click the Generate Travel Areas tool. In the configuration, set:
   • Input layer: hospitals (emergency rooms) layer
   • Cutoffs: 5 (minutes)
   • Travel direction: Toward
   • Areas from different points: Split
   • Output name: will appear in your Content.
   • Environment settings: Processing extent > Display extent (make sure the map is zoomed in as tightly as possible on the hospital points but also be sure every hospital is visible)
3. Click Estimate credits to make sure the credit usage is reasonable (less than 10 credits for this example).
   warning_amber The next step will consume your ArcGIS Online account's credits. Use the `Estimate credits` link each time you run the tool to ensure you will not use all of your allocated credits. Check your balance in your account settings on ArcGIS Online.

   

4. Click Run.
5. When the task completes, close the analysis tool and view the results on the map. You will see asymmetric polygons around each hospital location, representing the area for which a drive to the hospital would take 5 minutes or less.
6. Now we need to count the population within those travel area polygons. Click the Analysis widget again and this time choose the Summarize Within tool with the following settings:
   • Features to summarize: USA Census Block Points
   • Summary polygon layer: your generated travel areas
   • Field statistics: +Field and select the 2020 population field
   • Output name: will appear in your Content.
   • Environment settings: Processing extent > Display extent (make sure the map is zoomed in as tightly as possible on the hospital points but also be sure every hospital is visible)
7. Check the credit usage, run the analysis, and once the task completes, close the Analysis widget.
8. On the map, click one of the polygons in the new Hospital Service Area Population polygons (you can hide the old polygon layer using the Layer List widget). In the popup, there should be a new field added for the 2020 population sum.

Try it

1. Reload your app to clear the hospitals and service areas.
2. Use the Add Data widget to add a new layer in your app. This could be your points of interest from Assignment 3, a layer you find in ArcGIS Online, or any other sources. For example, you could search for Taco Bell and add the layer in the results from EsriMedia.

1. Calculate the service area population for the new layer, e.g., how many people live within a 5-minute drive of a Taco Bell.
2. Find the service area polygons layer with population you just created in Step 3 in your Content and go to its Item Details page. Fill out the fields:
   a. Title
   b. Summary
   c. Description (<200 words):
   1. Explain what the layer is, how it was created.
   2. Give example population count for one of the locations in the layer you chose, e.g., “Our Lady of the Lake Livingston has a 5-minute drive service area population of 9,717.”
   3. Link to your app.
      d. Terms, such as “None” or “CC BY-SA”.
      e. Credit the source of any data used to generate your layer
3. For the link you will submit, copy the link to your travel area layer’s Item Details page using the social icons on the right side of the page:
   
   Get the link to your Item Details page by clicking the Link icon.

Checklist

1. Item Details page with basic info for the feature layer of the service areas you generated using your own layer (not hospitals) with your app.
2. Description of the layer and how it was generated.
3. Example population for one of your locations, given in the Description.
4. Paste a link to your app in the Description.

Submit

1. The URL to the Item Details page of your feature layer. Example: https://www.arcgis.com/home/item.html?id=ABC123 or https://arcg.is/ABC123