Extreme care should be taken with an awareness that the used HYSPLIT forecast was developed mostly for long-range transport purposes. Furthermore the amount of radioactive material emitted has not been quantified. It should also be noticed that local surface winds are largely effected by topography and structures therefore, wind patterns near the ground are likely to be different from synoptic scale patterns.
I will note that it is vital to understand that these are models, not measurements.
I just came across A User Study on Visualizing Directed Edges in Graphs by Danny Holten and Jarke J. van Wijk. The problem they look at in this paper is how to represented directed edges in visualization of graphs, e.g. to represent A is a part of B or A likes B, etc.
Interestingly, their results indicate that what I suspect might be the most commonly used approach (placing an arrow head at the end of the graph) is not the best. Rather, they suggest, using the tapered elements illustrated below is better.
The BBC site Dimensions (with the url howbigreally.com) takes well known objects and extents (e.g. the moon, floods in Pakistan) and projects their geometry onto a map. This provides an interesting way to help understand our world - both natural and manmade.
Benjamin Hennig, who writes at Views of the World, has created a cartogram which visualizes both population and earthquake statistics. As with other cartograms, the population is mapped to area. This combination of statistics goes some way to indicating areas of the world where more people might be impacted by seismic activity.