Election Pollocks | Maps We Love

Why we love it

Politics can be a messy business. Most election maps show the winners without the voting nuances. We love this map because it makes a visual metaphor of the election results using artistic design inspired by Jackson Pollock. Symbology mimics Pollock’s famous paint splattering to show complexity in the 2015 UK General Election. The 13 different parties are represented by their colours and paint is applied to 650 political constituencies to create a visually arresting image.

Why it works

For each of the 650 constituencies, four symbols are added to the map to represent winners, runners-up, third place, and others. Symbols are offset, sized proportionally by vote number, and randomly rotated to give the sense of paint splatters. Transparency mutes all but the winner’s symbols for an overall impression of a messy mix of paint. Against a dark grey canvas, colours pop and then blend just as they do in electoral geography.

Important steps

Group by constituency

Join election results by political constituency to a point feature class representing the center of each constituency polygon.

Add layers for voted category

Create four layers of point features to serve as layers for winners, runners-up, third place, and others. Apply offset rules to each layer in ArcGIS Pro.

Each category needs a symbol

Design and use picture marker symbols to represent each of the political parties per constituency, per layer.

Marker symbol layers

Resize symbols proportionately

Resize symbols (proportionally to the number of votes and rotated randomly) using attribute-driven symbology in ArcGIS Pro. Publish the map to ArcGIS Online as a tile service for four scales.

Attribute-driven symbology

Publish

Publish the map to ArcGIS Online as a tile service for four scales. The actual results were published separately to drive pop-ups on the final web map.

Requirements

Data and software

Results for the 2015 UK elections were compiled into a spreadsheet as they were reported on election night. These were joined to a dataset of UK political constituencies. Software used: ArcGIS Pro.

Analysis

The data has to be formatted in such a way to allow four layers to be built from the original dataset. This required a bit of summation of various raw numbers in Excel before bringing it into ArcGIS Pro.

Time

Collating the data on election night was the biggest time requirement for this map. The map itself took a day to build with most of the time spent iterating the symbol offsets and sizes to create the desired look and feel.

Tips and tricks

Customise map symbols

Attribute-driven symbol design in ArcGIS Pro gives you a flexible design environment to customise map symbols as you wish. Use Web AppBuilder for ArcGIS to restrict viewing scales to those with data.

Make your symbols pop

When using highly saturated symbols, the dark grey canvas map provides a perfect backdrop to make the symbols pop.

Reduce complexity

The geographic constituency polygons (with full election results) were generalised to reduce complexity and improve draw speed. They are symbolised with no colour and no outline and published as a feature service to act as a layer that drives the pop-ups.