Louisiana's Death Alley

Learning outcomes

Creating map layouts
Cartographic techniques to highlight a study area
Practicing table joins
Set ArcGIS Pro environment settings

Introduction to Cancer Alley / Death Alley Louisiana, USA

Outside of the class, watch the video linked below from RISE St. James and Forensic Architecture (FA) and read . You are encouraged to explore more of the resources available on the project website:

Environmental Racism in ‘Death Alley’, Louisiana (~30 min)
Read:
- Environmental Justice (Mohai, et al.) Section 3. DISTANCE, COMMUNITY PERCEPTIONS, AND IMPROVING METHODOLOGIES
- Before continuing onto the exercise, please read and interact with ProPublica’s 2019 StoryMap: In a Notoriously Polluted Area of the Country, New Chemical Plants are Still Moving In.
  - Note: this is where you can locate the list of 7 counties for your analysis.

In Part 1 of this exercise, you will map the corridor along the 85-mile stretch of the Mississippi River between Baton Rouge and New Orleans along with the locations of petrochemical and other industrial facilities which are required to participate in the Toxic Release Inventory (TRI) Program, ground level particulate matter 2.5 (raster representing air quality), and demographic data from the U.S. Census, contrasting this region with the rest of Louisiana state.

In addition to applying best practices for managing vector data, you will also use a few advanced cartographic techniques to focus your area of interest through visual hierarchy and make an aesthetically pleasing map.

In Part 2, you will create a web map and web application with some of the same data sets along with air quality. Part 2 does not require ArcGIS Pro and can be done from any computer.

PART 1

Assembling your vector data

Start ArcGIS Pro and create a new project, naming it Louisiana_Cancer_Alley_<your name>. Insert a new map. Don’t worry about selecting a base map at this point; you’ll be changing it later, just before making your layout.

Set ArcGIS Pro project environment settings

Set the Output Coordinate System to into the Universal Transverse Mercator (UTM) coordinate system for all geoprocessing operations:

- Use the web tool linked above to identify which UTM projected coordinate system contains most of the state of Louisiana
Set your geoprocessing environmental settings to the projection you identified:

Open the Environment window → Navigate to the Analysis ribbon → In the Geoprocessing group on the toolbar select Environments
Under Output Coordinates select the globe icon
Search for the UTM projection you identified using the link above
- Use the drop down arrows to find this projected coordinate system (we'll talk about these more in week 10)

Add a USA state layer

Create a new feature layer of the Louisiana state boundary and save it in your project geodatabase. See the steps below.

Ensure this new feature layer is projected into the Universal Transverse Mercator (UTM) coordinate system.
- Use the web tool linked above to identify which UTM projected coordinate system contains most of the state of Louisiana

Set your geoprocessing environmental settings to this projection.

In the Catalog Pane → Portal → Search/browse Living Atlas for “United States State Boundaries”

Add a counties layer

Generate a feature layer of the seven parish (Louisiana counties are called parishes) boundaries.

Search the Living Atlas for the USA Counties Generalized Boundaries

Add a Toxic Release Inventory (TRI) layer

Open a web browser and go to the TRI customized search tool on the Environmental Protection Agency (EPA) website. Follow the instructions for a Envirofacts TRI Customized Search.

In Step 1

Select Release Information for Water, Air, Surface and Underground Injection. Select the additional subject, Facility Information.

Click the button to go to Step 2 tables.

Select both tables that appear: v_tri_release_qty and tri_facility.

In Step 3, select the following fields/columns:

TRI Facility Id
Environmental Medium
Total Release (note: the unit is pound)
Facility Name
Street Address
City Name
County Name
State Abbreviation
Pref Latitude
Pref Longitude

In Step 4, in the Reporting Year window, enter “2023”, in the Geography Search window, enter the State abbreviation for Louisiana and set output to a .CSV file. Note: this option is located at the bottom of the web page and it may take a few minutes to generate a file. Download the file, move to your working directory and open to examine the column field names and values.

Find TRI.FACILITY.PREF_LONGITUDEPREF_LONGITUDE (Note that EPA shortens the names of these to PREF_LONGITUDE and PREF_LATITUDE when viewed in your geoprocessing tools and attribute table).

If there are no minus (-) signs indicating the coordinates are located west of the prime meridian (as all longitudinal values are in the United States), this data file will have to be augmented before it can be properly added to your map in ArcGIS Pro. In a new blank column next to PREF_LONGITUDE, type the field name, LONGITUDE, in row #1.

Click in the empty cell just below the field name (row 2) and type the following formula:

= -1*J2

and hit Enter

This will multiply the value in your PREF_LONGITUDE column and produce the correct coordinates for mapping TRI facilities in Louisiana. Copy the cell (Ctrl button and C); hold down the Ctrl and Shift and Down Arrow keys to highlight all the remaining cells in the column; paste the formula. Save and close your .csv file.

NOTE: not all of the valid TRI records have latitude and longitude coordinates; some values are null. These records will be calculated as a “0” in your new column, but are not a cause for concern. However, records for which there are no values in any of the fields except “0” in the Longitude column [created by pasting the formula to the entire column] need to be deleted. The correction will be made in ArcGIS Pro.

Add this revised table to your map as XY data, ensuring the correct fields are selected for running the tool, REFRESH folders in the process. After displaying on your map, export the layer to your project database and project in the same coordinate system as your other vector data.

Note: you might need to add your table to the ArcGIS Pro project home geodatabase before conducting this step.

Before going further, create appropriate metadata for each of your 3 new layers.

Make sure to export these layers to your geodatabase and replace your existing layers, to ensure they’re within your project geodatabase. [HINT: Catalog → (your project geodatabase) → Export → Feature Class(es) to Geodatabase… → (your desired feature layers) → Run]
Right click on the layer in your geodatabase --> select Edit Metadata --> enter information to describe the layer in the required fields and select Save

Submit on Brightspace: Take a screenshot of your geodatabase (in the Catalog pane) showing your saved layers and upload to Brightspace.

Remember to save your project periodically as you progress through the exercise.

Symbolizing vector data

Open and review the attribute table of the TRI facility dataset.

There are thousands of records, with many facilities listed multiple times. Currently, the EPA tracks 770 different chemical releases in 33 different categories with the TRI program, and the majority of industrial facilities in Louisiana emit multiple chemicals, via different environmental mediums – air stack, fugitive air, water, etc.

For the sake of simplicity, you are going to symbolize the total pounds of ALL chemical emissions regardless of medium per each facility. To do this, you will need to produce a summary table. However, there are also “false” records with no value except “0” in the Longitude column (see note above). These need to be deleted before proceeding.

Select and then remove the null fields in PREF_LONGITUDE

Use the following clause in the selection dialog:

PREF_LONGITUDE is null

Go to the Edit tab → Features → Delete (this may take a few moments), and save your edits (Edit tab → Manage Edits → Save)

With your TRI attribute table still open, right-click on the field TRI_FACILITY_ID and select Summarize.

In the Summary Statistics window, enter “TotChemFacility” for the Output Table name, In the Statistics Field, select TOTAL_RELEASE from the drop-down menu, and select “Sum” in Statistic Type, and take the default entry for the case field and click OK. Your new table upon opening should look similar to the illustration below:

Join this table to your TRI layer using the Facility ID field as your join key

Note: reference this example for more information on conducting a table join). Symbolize your TRI dataset using graduated or proportional symbols on your SUM_TOTAL_RELEASE field, selecting a color and symbol of your own choice. Set max size to 25.
Symbolize your seven-parish boundary dataset, using No Fill for the polygon color and a black, 3-pt outline.

For the state of Louisiana, you will employ figure-ground contrast, a cartographic technique used to establish visual hierarchy. There are multiple ways to do this, for this map, you will create a floating/shadow illusion.

Select the Louisiana feature layer and go to Symbology → Gallery:
Select Black Outline, 2pt.
Go to Properties → Symbol and change the Outline width to 5 pt.
Click on the Layers icon and change the Solid stroke to Gradient stroke.
By default, you’ll see a black to white gradient, with color #1 set to black and color #2 set to white:

Click on the drop-down arrow next to color #1 (black) and select Color Properties and change the Transparency level from 0% to 100%.
Click on the drop-down arrow next to color #2 and change the color to black (RGB = 0, 0, 0).
Expand the Offset options and enter the following parameters:
- Offset = 10 pt
- Method = Miter
- Options = Accurate

Add another thematic layer, a new base map, and create more “focus”

Add a race/ethnicity Layer

Search Living Atlas and add the “ACS Race and Hispanic Origin Variables – Boundaries” dataset (feature layer). Remove the State and County layers so only the Tract layer remains in your Contents pane.

Another way to add focus is through definition queries. Select your Tract layer and right-click with your mouse and select Properties. Choose Definition Query and create a new definition query in which the field, “State” equals ‘Louisiana’ and click OK.

None of the 10 standard base maps except for the dark gray or light gray canvas are appropriate as background, though even these two could be better.

ArcGIS Online offers several other options

- Search for “Khaki Base Map'' in ArcGIS Online within the Catalog pane and add it to your map.
- Remove any other base maps from your Contents pane drawing order.

Blending in ArcGIS Pro to create focus

A new visual effect option called Blending became available in ArcGIS Pro in December 2020. There are many applications and many different modes with which to experiment, and it can be applied to any 2D layer in any map or scene.

Select your Census Tract ACS Race layer:

Navigate to Feature Layer → Effects → Layer Blend.
From the drop-down menu, under “Darkening Modes,” select Multiply.

Layout 1: Toxic Release Sites and Race-ethnicity

Insert a new layout → ANSI Landscape → ANSI C (17” x 22”). Add a map frame of your Louisiana map, making it the same size as your printable area. Zoom to your Louisiana state boundary layer. Before adding any additional elements, your map should look similar to the image below. Note: your map map not display precisely as it appears in the screenshot.

Add a title, some brief descriptive text, your name and citations (See section titled: Data Citation Elements), north arrow, scale bar, and a legend.

Notes:
- You only need to add a citation for the data layers, TRI and race-ethnicity layers.

Submit on Brightspace: export the layout to your project folder as a PDF.

Layout 2: Ground-level Air Quality PM 2.5

In the Catalog pane, create a copy of the layout you just completed for layout 1.

Right-click on the layout → Duplicate

Navigate back to your map and turn off all layers except your base layers: the seven parishes and Louisiana state boundary.

Adding a raster dataset displaying air quality: particulate matter 2.5

Next, you will add the same surface level PM 2.5 layer as displayed in the Forensic Architecture reporting linked at the beginning of this document.

Visit the Washington University Atmospheric Composition Analysis Group web page with their Surface PM2.5 datasets: https://sites.wustl.edu/acag/datasets/surface-pm2-5/#V5.GL.03

In the section titled “North American Regional Estimates with Composition (V5.NA.04.02)” locate:

"Annual, monthly, and biweekly mean total and component PM2.5 [ug/m3] at 0.01° × 0.01°" →
- Select [NetCDF]
- Select GWRPM25
- Select North America
- Download the .nc (NetCDF) file for 2014
- Place the file on your external drive

Add the data to your ArcGIS Pro map:

In ArcGIS Pro navigate to the Analysis in the top toolbar ribbon → select Tools which opens the geoprocessing tools dialog on the right side of the screen → search Geoprocessing for the “Make Multidimensional Raster Layer tool”
For Input Multidimensional Raster, click the folder icon to locate the .nc file you have downloaded → rename the Output Multidimensional Raster Layer to “surfacepm25_2014” → accept the default settings and click Run.

Clip the new raster layer by the Louisiana state boundary layer extent:

Return to the geoprocessing search (Analysis ribbon → Tools)

search for the “Clip Raster” tool
for Input Raster use the drop down menu to select “surfacepm25_2014”
Select the box for “Use Input Features for Clipping Geography
accept the remaining default settings and click Run

Prepare your map for the new layout:

Turn off all layers except for the Louisiana state boundary, the seven parishes, and the new pm2.5 layer.
Edit the title, citation, brief description of the map, and legend as needed to reflect the new air quality layer being displayed.

Export the layout to your project folder as a PDF.

Submit on Brightspace: Layout 1 and Layout 2

PART 2

In Part 2 you will create a web map and web application with some of the same data sets along with air quality.

NOTE: Part 2 is completed in ArcGIS Online, not the ArcGIS Pro desktop application.

Creating a web map

Log into ArcGIS Online and, from the Content page, search My Organization for the following two shapefiles and download (but do not unzip):

• LA (the Louisiana state boundary)

• The Seven Parishes of Cancer Alley (the parish boundary)

Return to ArcGIS Online and open a new map and add these two shapefiles in the Catalog pane. (for the layers search My Organization)

Toxic Release Inventory

Search My Organization again and add the feature layer:

TRI2020la (note: search for TRI2020)

Cancer Risk from the U.S. EPA National Air Toxics Assessment

On the left side toolbar select “+ Add” → “Browse Layers” → Search “My Organization”
Search for “Cancer Risk NATA19AC_CRP_CRSG”
- The layer is already symbolized to show the cancer risk by census tract
- Rename the layer to have a descriptive name

Create two bookmarks that include a zoom to (this step is important for when you create the web app) :

Louisiana state
Cancer Alley

To create the bookmarks:

Zoom to desired extent → Map tab in your tool ribbon → Navigate → Bookmarks → New Bookmark → Name your bookmark → OK

Be sure to order your layers so that all are visible, e.g. your boundary layer state outline and county (parish) outline layers should be at the top of the layer list.

Save your web map, naming it CancerAlley_YOURNAME

Creating a web app

With your web map still open

Go to Share → Create a Web App (gray button).
Select “Use Instant Apps” (if not selected).

The Instant Apps gallery page opens.

This page provides information and guidance to help you choose an appropriate app template. When browsing the available apps, you can click the button next to each name for more information. Instant Apps checks the data and configuration of your map.

If your map doesn't meet the requirements for an app, a warning message appears on the thumbnail to inform you. You can also search the apps for a particular capability or tool.

Create a Sidebar application in ArcGIS Online

In the Instant Apps gallery, choose Sidebar.
Specify a:
- title (ensuring the name ends with your initials),
- tags (EJ Tutorial Death Alley, Bard College, the semester you are taking this course e.g., Fall 2024)
- A brief summary that describes the purpose .

Map in Express Setup

Map - Step 1: Select the web map you just created. Click Publish, and then Launch.
Map - Step 2: Hit “Next” and give your app an appropriate title
Map - Step 3: Click on “Next” and choose Legend panel to open at start and enable the following:
- legend panel
- layer list panel
- bookmarks
- pop-up panel
Map - Step 4: Take all the default search options
Map - Step 5: Select theme and widget positions of your preference. Publish and confirm.

Towards the top left corner of the window, turn off the Express setup button.

Select About and add the following:

App title
Turn on the introduction panel button, and add an Introduction panel title: Mapping Air Quality in Death Alley
Introduction panel text:

The industrial corridor that stretches alongside the Mississippi River from Baton Rouge to New Orleans is often referred to as “Cancer Alley” or “Death Alley” because of the health risks associated with local chemical emissions and the area being home to a high concentration of plantations during the Enslavement.

Enter "Explore" for the introduction panel button text

Add text to the Details section of Sidebar with the following steps:

Return to the left hand toolbar and click on Sidebar.

Scroll down and turn on the button for Details.
Click to Edit details content.

Enter the following and your response to the following prompt:

This map allows for a comparison of toxic release inventory sites and cancer risk in Louisiana’s “Cancer Alley” or “Death Alley” and other regions of the United States

In the details content text box respond to the following prompt:

Describe the relationship you observe between TRI sites and cancer risk in the seven parishes. If you were to continue this analysis, what other indicators would you explore to better understand these relationships?

Enable all the other features in the Sidebar options window before saving your draft.

When finished, publish your web app and submit a link on Brightspace, along with a screenshot of your geodatabase, and an export of the two map layouts you made in Part 1.

Submit on Brightspace

Copy the URL link and submit on Brighspace in a word processing document OR the submission textbox on the assignment submission page.

Submit on Brightspace

Screenshot of your geodatabase
PDF of Layout 1 featuring TRI and race/ethnicity
PDF of Layout 2 featuring Ground Level Air Quality
A link to your Sidebar web app

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