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Class-Specific Resources

Moving Maps Online

In this tutorial, we’ll explore one method of moving your digital maps online using the web-based tool ArcGIS Online. For this exercise, we’ll be mapping data from George Reid Andrews's Afro-Latin America, 1800–2000, which lists the dates that countries in the Americas passed slavery abolition laws. We’ll begin with a brief task in QGIS of joining the Andrews data to a country boundaries file. Then we’ll take the file we export from QGIS, load it into ArcGIS Online, and visualize it in two different ways.

Before you begin, you should make sure that you’ve claimed your UCSC-affiliated ArcGIS Online account (this is different to their free public accounts). All students in LALS 194 should have received an email with the subject “An invitation to join an ArcGIS Online organization, UC Santa Cruz” that includes detailed instructions on how to do this. Contact your instructor or the DSC if you did not receive this email or have trouble logging in.

Contents

STEP 1: Joining Data in QGIS and Exporting

Before we move our mapping data to ArcGIS Online, we need to assemble the data file in QGIS. This will require us to join a country boundaries file to the data on abolition dates we have from page 57 of George Reid Andrews's Afro-Latin America, 1800-2000. Note that we haven't included data for countries that didn't gain independence until the late-nineteenth or twentieth century and thus abolished slavery under colonial rule (i.e. Canada, Belize, Guyana, Suriname, and French Guiana).

  1. Open QGIS and create a new project. Save it as “Americas-abolition.”
  2. Download the Americas dataset and add it to QGIS by going to Layer > Add Layer > Add Vector Layer. Note that this is strictly a country boundaries file. Adding in the abolition data comes next.

Map of the Americas

  1. Next download the Andrews spreadsheet and add it to QGIS by going to Layer > Add Layer > Add Delimited Text Layer. After you browse to find the file, make sure CSV is selected for File Format. Under Geometry Definition, select “No geometry (attribute table only).” Then hit Add and Close.

File upload window

Now we’ll join the spreadsheet data to the country boundaries file.

  1. Right click on the Americas layer and select Properties.
  2. Select the Joins tab.
  3. Near the bottom of that window, press the + icon.
  4. For “Join layer” select “Andrews_p57-updated.” This is the layer we’re joining to the Americas layer.
  5. For “Join field” select “COUNTRY.” This is the column of data in the Andrews spreadsheet that we will match.
  6. For “Target field,” select “ADMIN.” This is the column of data in the Americas file that corresponds to the “COUNTRY” column in Andrews. In other words, this is where we’ll find our matches.

Join Field options

  1. Click OK. Then click Apply and OK.

Now select the Americas layer, right click, and select Open Attribute Table. You should see the columns of data from the Andrews_p57-updated spreadsheet added to this layer’s data. Note that not all countries from the boundaries file will have data from the Andrews spreadsheet.

Data from the Andrews spreadsheet in the program

Our last step is to export this joined data as a new file that we can load into ArcGIS Online.

  1. Right click on the Americas layer and select Export > Save Feature As…
  2. For Format select GeoJSON. Browse to select a folder to save your file in and give your file the name “Americas-abolition.”
  3. Click OK.

STEP 2: Moving Data into ArcGIS Online

This step in the process assumes that you’ve set up an ArcGIS account that’s affiliated with UCSC. Navigate to https://www.arcgis.com/ and login with your credentials. (Contact your instructor or the DSC if you did not receive an email prompting you to set up the account or have trouble logging in.)

Once you’ve logged in, we’ll begin by loading the new data file into your account and getting it ready to map.

  1. From the UCSC ArcGIS Online homepage, click “Content.” This opens the page that lists all of the data you’ve loaded into your account. For now, it should be blank. Note: The homepage is pretty bare, but the top menu will lead you to all the places you might need to go in future. Most importantly, the Map link launches a new map project and the Content link takes you to all of your created content, including datasets and maps.

UC Santa Cruz ArcGIS Online homepage

  1. In the top left, click Add Item > From your computer. Use the Choose File to find and select Americas-abolition.geojson, the file you just exported from QGIS. Make sure that "Publish this file as hosted layer" is checked. Input the title “Americas Abolition (Your Last Name).” Finally, ArcGIS Online requires you to give your uploads at least one tag, so tag this file by entering “history” in the Tags field. Then click Add Item.

Upload screen

  1. This should automatically take you into the details page for this data. It may take a minute or two to fully load. There are a number of things you can do on this page, but for now we only need to do one—enable the data layer to display a time animation. Just below the Description heading, you should see a Layers heading. Within that section, click Time Settings.
  2. In the Time Settings popup, check the box for “Enable time.” Below that, make sure that “specific events in time” is selected—the alternative choice "time ranges with a start and end time" would be for instances where an event runs over a period of time rather than ocuring once. Finally, make sure that the “FINAL ABOLITION DATE” column from your data is selected in the drop down menu. Then click OK.

Time settings options

(Note that for now we are only visualizing the date of final abolition, but with the data we have we could alternatively visualize the end of the slave trade or the free womb laws. In order to highlight either one of these, we would simply make that selection in the drop down within this “Enable time” menu.)

Now your data should be ready to map with time animation. The next and final step will be to create a map with this data.

STEP 3: Creating a Time Animation Map

There are a few ways to create a new map in ArcGIS Online, including simply clicking Map in the topmost menu. But since we’re already viewing the data that we want to map, it will be faster to “Open in Map Viewer” in the right hand menu.

  1. Click Open in Map Viewer. You should see a map interface appear that bears some resemblance to QGIS. The map preview is the main part of the screen. To the left is a menu that will allow us to style our layers. At the top there are various options for adding, saving, and exporting data. And since we’ve enabled time for this data, at the bottom of our map is a timeline feature.
  2. Look at the style menu to the left. Right now, you’re seeing a list of style options based on the column in your data that is currently selected. Let’s keep things simple for the moment by selecting “Show location only” in the top drop down menu labeled “Choose an attribute to show.”

Selecting attributes to show.

  1. You should now see only one drawing style in the left menu. You can click options to change things like color and transparency. From this options menu, click OK. Then at the bottom of the style menu, click DONE. You’re now seeing the main left hand layers menu.
  2. Before we go further, click Save in the top menu. Give your map the title "Americas Abolition (Your Last Name)." Add the tag “history.” Then hit Save Map.

Now let’s do some additional styling and get our time animation feature working.

  1. First let’s change our basemap. In the top menu, click Basemap. You can try out any of these basemaps, but a simpler one might be ideal so that our data layer will pop. Consider either Dark Gray Canvas or Light Gray Canvas, taking into account whatever color you selected for your data layer.

Dark grey base map example.

  1. Now look at the time animation controls at the bottom of the screen. Click the button to the far right that looks like two slider bars. Here you can adjust the speed of the animation—let’s leave this at the default setting for now. For more controls, click Show Advanced Features.
  2. Time Span should by default be set to the whole range of time that your data covers. You can leave this alone.
  3. Under Time Display, you can set the interval to step through your time data. We’ll leave it at the default of 7 years. Then for “As time passes” change that setting to “progressively display all data.” This means that the data will accumulate on the map as the time animation proceeds. Hit OK.

Time setting option panel.

  1. Finally, click Save. ArcGIS Online does NOT save your map changes automatically.

Now hit play on your timeline. You should see countries appear on the map according to the date they passed abolition legislation.

STEP 4: Creating a Color Ramp Map

The time series map is one useful way to visualize this data and can be shared with others for viewing directly in the ArcGIS Online interface. But unfortunately the time animation feature does not work within StoryMaps, which is where you will ultimately want to display this map. For that reason, let’s go through the steps to visualize this data in a slightly different way with a color ramp to indicate the year sequence.

  1. First we’ll turn off the time animation feature within this map. Do this by clicking the More Options button (...) for the Americas Abolition layer and selecting “Disable Time Animation.” You should now see all of the countries displayed at once on the map.

More Options panel

  1. Next click Change Style for that same layer (it’s the button with an overlapping triangle, square, and circle). For “Choose an attribute to show” select Andrews_p57-updated_FINAL_ABOLITION_DATE.
  2. Make sure that Continuous Timeline (Color) is selected for the drawing style. Note that you can click “Options” for this style to customize the colors. There are also other drawing styles available as you scroll down that might be appropriate for other kinds of data. Again, just note that they are there for future experimentation.

Color options for Continuous Timeline

  1. Click Done.
  2. Save your map.

Now you have a map that shows countries colored from darker to lighter based on when they passed slavery abolition laws. This will display correctly in StoryMaps

STEP 5: Sharing Your Map

When you've finished your map, you can share it in a couple different ways.

  1. In the top menu, select Share (it's just to the right of Save).
  2. To share the map via a URL, simply copy the URL displayed under "Link to this map." Note that checking "Share current map extent" means that anyone who navigates to that link will see the map at the zoom level and focus you currently have set. You can go back to your map and adjust the zoom and focus to change this. As always, be sure to save your map!
  3. To share by embedding your map on another website, you will first need to check "Everyone (public)" under "Choose who can view this map." Then near the bottom, click Embed in Website. There you'll see a number of settings which you can leave alone or adjust as you desire. When you have everything set, click Copy by the code field under "Copy and paste HTML to embed in website." Then paste that code into the website where you want to embed the map.

You may also notice the option to Create a Web App from your map. We won't be discussing that option here, but the next tutorial will deal with one of those apps—StoryMaps.