Module 7, Thursday morning and afternoon, June 25
You have already learned how visualizations such as charts and graphs are a great way to show your audience important numbers and trends. Mapping can do that, and more. It is both a way of visualization, and another way to analyze your data. Maps help answer the questions “where” and “where in relation to other things?” You can find out where the landfills are and where they are in relation to low income neighbourhoods.
Mapping has become a central part of the data journalism world, and ArcGIS Online is a great way to put your data onto a map and analyze it.
During COVID-19, maps have become a common way to show the geographic spread and extent of the epidemic. Mingsze Ho of Esri Canada is going to walk you through how to use ArcGIS Online in a series of videos.
Mingsze has created this tutorial to go along with the videos. She recommends that you keep it open in another tab while you follow along with the videos as it contains important supporting materials. The data sources for her videos are included in the tutorial. Mingsze will host one live session for each group in the evening today.
There are two datasets you need to download for the videos. One is a shapefile of Toronto neighbourhood boundaries and the other is a csv file of the locations of food banks. If you are unsure of what a shapefile is, it is explained in the videos and on page 121 of The Data Journalist.
Watch the following videos on using ArcGIS Online. The division into the morning and afternoon is suggested. You should finish each video before proceeding to the next one.
Video 2, building a map
Video 3, enriching a map with additional data
Video 4, styling your map
Video 5, adding point data
Watch the remaining videos on using ArcGIS Online:
Video 6, popups
Video 7, doing map analysis
Video 8, sharing your map
Video 9, dashboards
Video 10, story maps
Additional optional exercise:
In this exercise, you will upload data on COVID-19 cases and rates in Toronto neighbourhoods, and make a choropleth map displaying the cases. You already know how to do the latter, as you already styled your first map depending on the percentage of residents who are seniors.
In this exercise, you will also learn how to join an external table to a map.
The data for this exercise is in a CSV. It has all cases of COVID-19 up to June 23, as well as the rate per 100k, for all neighbourhoods in Toronto. The data was downloaded from the Toronto COVID-19 dashboard. The only change we made was to add the neighbourhood ID, to make it easier to do the join. You could do this yourself if you downloaded the data in future.
Before you begin this exercise, read this tutorial on joining tables in ArcGIS Online.
From here, we presume you have read the above tutorial.
You already have a layer of Toronto neighbourhoods saved in your account, so go ahead and add that to a new map. Now, upload the CSV file on COVID-19 cases and join it the neighbourhoods map, as explained in the tutorial.
Now, style the map as a choropleth, to show the rate of cases of COVID-19 in each neighbourhood in Toronto. Think about your break points between colours. Perhaps divide the colours into quartiles or quintiles, which is a statistically sound way to look at epidemiological information. And try making the map with the straight numbers. Is it different? How? Generally speaking, we don’t want to display raw numbers on maps because the numbers are affected by other factors, such as population. Rates correct for that population difference.
Finally, in areas with high rates, can you find evidence that some were driven by outbreaks in places such as long-term-care homes? Go explore. Mapping is fun!
Live session east: 7 p.m. Atlantic, 6 p.m. Eastern
Live session west: 7:30 p.m. Eastern, 6:30 Central, 4:30 Pacific
From the textbook: Chapter 6 of The Data Journalist covers all of the key concepts involved in online mapping. If you want to explore using the desktop version of ArcGIS, for which you may be eligible under the Esri Canada media program, this is covered in chapter 7 and its accompanying online tutorials.