Thursday 23 April 2020

Creating heat maps to compare the countries afflicted by Covid-19 for VRT NWS

With data coming at us from all angles, not a lot of graphs show us a relevant and quick comparison between countries. With the help of heat maps, it becomes easier to compare data from several countries, giving us a clear oversight of which countries have been hit the hardest or littles by the Covid-19 pandemic.




In the graph made by Peter Stouthuysen, Data Visualization Expert and Tableau Expert, you can find a comparison between the different countries affected by the Covid-19 outbreak. The darker the color of the block, the more infections were counted or registered that day. Graphs like these are called heat maps.


The green dots indicate semi- or full lockdowns instigated by the governments of said countries (this implies strict measures were taken such as the closing of schools, shut down of public services, bans on gatherings of more than a certain amount of people, stores and restaurants were closed, etc.) or the country closed its borders. The graph demonstrates that taking these measures does not have an immediate effect. This is why the strict obedience of these measurements is required to reach the desired effect that experts call: “flattening the curve”.


The charts (made with Tableau) are updated every day but the data always lags 1 day behind.


You can find the chart depicting the number of new infections per day here. The chart demonstrating the number of new deaths per day can be found here.



While every country shares the amount of infected, deceased, hospitalized and healed people in their country every day; these are not numbers that mean much on their own. It’s much more relevant to keep track and look at the new number of infections added daily. However, this number also comes with a set of limitations. When a country changes testing methods or rules halfway through a pandemic, the numbers will change drastically. for instance, in China where testing was only done on people with severe symptoms at first but then expanded to people with mild to even light symptoms, the numbers increased exponentially to 10.000 new infections in one day. In European countries, we’ve noticed the opposite happen, in fact there testing went from broader criteria to now only very narrow criteria such as patients admitted into hospital or people working in the healthcare industry with severe symptoms. These are circumstances surrounding the test results that must be taken into account when viewing the charts.



Looking at the heat maps in further detail, we can also notice that once drastic measures have been taken by the governments of the countries in question, it still takes a significant amount of time for the effects of those measures to be noticeable in the data. By that, we mean a decline in the number of infections and deaths (which is called ‘flattening the curve’). This heat map demonstrates the need to adhere to the rules set forth by the government and why it’s so important to until told otherwise, stay home.




We’d like to once again mention that the amazing work Peter has produced, is done to create these clear charts providing oversight of the development of Covid-19 in all afflicted countries.  We are proud to collaborate with Peter Stouthuysen. Thank you, Peter!

Read the full article (in Flemish) on the official site of VRT NWS here.