Visualizing Geo Data with Time

How do you visualize geo data that changes over time? Visualizing data that changes both spatially and temporally is an open research problem.

There are 3 general ways to do so:

1. Animation

2. Faceting

3. Getting Rid of the Map Metaphor

Animation

The change over time is animated.

Animation can be catchy, pleasing and has a cinematic effect, but we must use it with caution.

The issue is that it can sometimes be hard to comprehend, since most animations are fast.

In general, animation works well when the trends are coherent and easy to follow.

Some ways to make animations more usable:

• make it user-controllable

• pair it with a timeline

• color objects according to time

• use traces (if appropriate) - show objects through time to depict history (shown below)

  

Faceting

This is also called small multiples.

This is a way to map time to space. Every map represents a single time slice.

Animation is harder to follow but has higher resolution. Faceting is easy to follow.

Another important point to note is that in an animation, since the states of the map at different timestamps are superimposed one on top of another, it is easier to compare the state of the map at different timestamps. However, in faceting, since the states of the map at different timestamps are located one after the other (in different locations), it becomes difficult to compare the state of the map at different timestamps.

Getting Rid of the Map Metaphor

Sometimes, we may be better off using other visualization methods (instead of maps) to visualize geo data that changes with time.