Using GIS to Factcheck Julius Caesar's Account of the Gallic Wars

Geographic Information Systems, or GIS, are used to visualize everything from climate change to political climates. Now this technology is also being used to verify historical records.
A team of researchers from around the world are using GIS to look into Julius Caesar’s accounts of his time in the Gallic Wars. Caesar’s commentaries on the Gallic Wars contain some of the most complete descriptions of Gaul and the people that lived there. But they aren't necessarily exact histories: they were written as memoirs, and Caesar was fighting the wars, in part, to boost his own political career.
So it makes sense to take his words with a pinch of salt. In the book, Caesar writes about a tribe called the Helvetii living in what is now Switzerland. They were running out of food to feed their population of over 250,000, so they packed up and tried to migrate to (or invade, depending on who you talk to) Roman-controlled territory. That turned out to be a poor choice. Even though Caeser was outnumbered, the war ended in the spectacular defeat of the Gallic tribe.
 Australian archaeologist Tom Whitley hopes to use GIS figure out whether it was even possible that the Helvetii had such numbers, or whether Caesar, many miles away from Rome, embellished his accounts to make himself look better in the eyes of his homeland.