A Roman Holiday

Not William Wilder's 1953 Gregory Peck & Audrey Hepburn flick (Wikipedia)! When drawing up a map of Apostolic Palestine for local Catholics, I ran across Ancient World Mapping Center (AWMC) at UNC-Chapel Hill. While their web app (ArcGIS Online) is a cool one-stop-shop for their rich data set - for ex. I cannot do point clustering (Comet Assistant) with my standard desktop license -  I loaded, picked apart an re-sorted some of their data for some interesting insights. 

Apostles in the Levant

That is what the Middle East was called in the Middle Ages (east of Western Europe where the sun rises or "soleil levant") and various ArcGIS Online sources composited this map. This was partly to show layout to a new "GIScionadio" (GIS aficionado). It shows Apostle Paul's long travels allowed by the Roman road infrastructure... 10,000 km. acc. to David Souchet's video on same (YouTube)!

click to enlarge, Tabloid size here

Ancient Roman environment

AWMC posted so many data that, failing clustering the points 😕 I clustered the features into environment and infrastructure groups (I may return to other s.a. Etropius Gazetteer & ?academics "VF" & "TTT" data groups I asked UNC about). This complete set of shape files shows the distribution of many features, some of which are tiny. Their legend is so good I kept it as-is, except for the Roman Empire extent I blended to mute it. 

click to enlarge & Tabloid size here

Look at the water features for example: you'll notice that the Danube and Ural deltas in the Black & Caspian Seas respectively. But for ex. the Tigris & Euphrates valleys and Arabian Gulf shoreline & inundation are significant, as described next.

Arabian Gulf

click to enlarge, original here

While I ask UNC what "late open water" mean exactly, see above the comparison among current & antiquity open water (sea + rivers in original tan), inland water (inundated in blue) & late open water in pink. What struck me is the extent of inundation in the Tigris & Euphrates (top left) and in the Gulf States (bottom) or in then Persia c/w today. Also in N Africa, I remember from high school Latin that present-day Sicily & the Maghreb were a wheat belt: indeed "Carthago delenda est" (Carthage must be destroyed) comes from the wealth of the N African coast competing w Rome at the time. So, like my CLIWOC maps, more climate data points on a historic scale.

Britannia

click to enlarge, original here

Likewise we see how the East Anglia marshes went far inland, also described in my blog here - medieval villages from a necklace bordering it - and present day Netherlands without dikes or windmill pumps was all water.

Ancient Roman infrastructure

Here you see the roads they're famed for, settlements & bridges, as indicative of their hold on the empire-building. I also add a curious study of malaria spread detailed here.

click to enlarge, Tabloid size here

Roads

In this closeup of Roman Britain, you see the network cross-country that surpassed any for a millennium afterward or more. I lived in Cambridge - Duroliponte then (Pleiades),  Latinised Celtic place‑name usually understood as “fort at the bridge” or “stronghold by the bridge” (Wikipedia) - and while Castle Hill was that Roman fort's locus, it also lay next to Reach an inland port in the pre-medieval marshlands (see above), and along the route you see angling up to the Wash indentation to the North Sea.

click to enlarge, original here

In fact the boomerang shaped route next to present-day Cambridge had a hilarious misfit described in this blog here: roads were built from both ends, from an unknown port near Kings Lynn (of later Hanseatic League) to the North and from Londonium to the South. While surveying is one thing Romans excelled at - they spanned the entire Roman Empire after all - the construction met in the middle, not far east of present-day Cambridge with a fifteen foot offset... the jog is still there today (click to enlarge):

Malaria

On the main map you see the overlay tones in blue (high) & greyscale (black to white the lowest): two millennia later the Po River Valley lost more people to Malaria than to WWII fighting I learned while living in Milan over a decade ago. The French coast of the Bay of Biscay was a marshland only dried when Napoleon planted pine trees for boat building. The present-day Rhone delta halfway in between is also blue. Interestingly the East Anglia marshlands North of present day Cambridge don't feature, due to colder climes? The Nile delta is also a surprise, but the original map here shows it warm not hot malaria-wise, which the overlay here doesn't show.

Conclusion

This is one interesting data set contrasting some changes (higher water inundation) and some constants (malaria in marshlands). Please enjoy some further exploration in the AWMC original ArcGIS Online Experience here: it's super easy to navigate... kudos to the UNC Antiquities team for the dataset and the web map!