We are 11 months into the COVID-19 pandemic in the UK and data has proven to be very important during that time. After a slowish start, the Public Health England dashboard has done an increasingly better job at showing UK-level or nation-level (England/NI/Scotland/Wales) data in an accessible way. At the start of April 2020 we started showing Local Authority-level data and visualisations because several of our sponsors work at that sort of scale and wanted a more local view than UK totals.
We've developed those Local Authority visualisations and dashboards over the past year adding a customisable dashboard that has shown cases, deaths and (when for the months where they were in use) the "tiers" of restrictions. Since the start of this year we've added vaccine maps of England which we update each Thursday with the latest age group splits from NHS England by 1st and 2nd dose.
Now, we've created another visualisation that combines all the Local Authority graphs of cases into a single graphic so that you can see both a national view and local variation at the same time. We've used a "stacked plot" approach - a style made famous by an album cover for Joy Division - which presents the data as a sort of landscape. This style of graphic has limitations (some parts will be hidden by others) but it can also help you spot some patterns more easily whilst also being quite eye-catching.
What does it show?
Each horizontal graph represents a single local authority with time starting at the end of February 2020 on the left and finishing with the most recent data on the right. We've ordered the local authorities so that the most northerly ones (by geographic centroid) are at the top and most southerly are at the bottom. To help you identify specific local authorities, view the full graphic and hover over any feature.
This type of plot shows how the shape of the pandemic has varied in different parts of the country - particularly within England. A first thing to note is that the first wave of the pandemic (March-April 2020) - over on the left side of the graphic - isn't very pronounced. That is because the levels of testing were very low so many cases went unnoticed. By the middle of the plot, testing had expanded a lot and the flat plains visible here are closer to the real situation. You can see little peaks on those plains that show the individual outbreaks at meat plants in Merthyr Tydfall, Wrexham, and the Isle of Anglesey, Leicester's longer-duration outbreak, and the outbreak at a sandwich factory in Northampton which led to local lockdowns last summer.
As you move over towards the right-hand-side of the graphic you can see the schools starting to go back in September with universities not long afterwards. However, this "second wave" seems to have affected northern parts of England and South Wales much more than south east of England and London. You can see the north largely (aside from some exceptions) has had distinct 2nd and 3rd peaks with a relatively low flat valley between them during December. The south east mostly had a very subdued 2nd peak with their cases rising sharply as the north's 2nd peak came to an end. This southern rise then shifts north as people "head home" for Christmas with it sharply rising in the north more-or-less from Christmas day. The subsequent post-Christmas national lockdown clearly brought cases down almost everywhere despite some later, localised, outbreaks in places such as Rutland and East Ayrshire.
This stacked plot will automatically update daily along with the existing dashboards. Hopefully it gives a slightly different look at the data that has become so familiar over the past year.