By SANDRA RENDGEN
Oh, the Mississippi. The ‘Father of Waters’, famous for its tendency to forge new routes – and its rather frequent flooding – is also a major commercial waterway. To shield residents from floods and ensure unobstructed navigation, the US Army Corps of Engineers has been in charge of works in and along the river. It also made these maps
This mind-blowing piece of cartography, one in a series of fifteen sheets by Harold Fisk, accompanied an extensive report issued for the US Army Corps of Engineers in 1944. A professor of geology in Louisiana, Fisk was fascinated with the meandering process of the Mississippi and sought to map its turbulent history. The report was the result of three years of intense field work, during which Fisk travelled with a colleague some 650 miles along the course of the river, investigating layers of deposits and recording historical river beds.
Since 1836, the river had been subject to minor and major interventions from the engineering corps, both to ensure navigation and to protect towns and cities from floods. However, measures such as building levees, and channeling or excavating the river, would at times elicit undesired effects – and were unable to hinder the disastrous floods of 1927. Fisk’s research can be interpreted as an effort to better understand the intricate and damageable ecosystem of the river – particularly in its tendency to continually create ever new courses for the river bed.
On a black-and-white base map, Fisk plotted both the current course of the river (white) as well as all the historical stages he was able to document (each one taking a different colour). In all, he was able to plot no fewer than 30 different river courses. The legend neatly labels the various courses – many of which, by the way, were reconstructed from aerial photographs.
Fisk’s colour system is effective once you take time to decipher it, but the initial impression is one of clutter – so many entangled paths crossing over each other. The current river bed is easy enough to pick out, but following any of the other courses is challenging. What, then, is the use of printing these mad, cluttered maps in which the main information is hard to decode in any detail?
One thing they certainly do is give an immediate sense of the river’s restless history, condensing an extremely long historical process (and its ecological consequences) into one snapshot. The meandering of the river has long been well known, but these maps are famous because their representation of this ongoing process – the constant meandering, cutting-off and opening of new river beds – is so evocative. These maps bring thousands and thousands of years of natural history to life. They make you see the river meandering. What more could you wish for from data visualisation?
Harold Fisk’s report and the high-resolution oversize plates from the reports (incl. the maps) can be downloaded from the website of the US Army Corps of Engineers. If you want a print of those hanging over your bedside, head over to Society6.
Sandra Rendgen is the author of two bestselling books on data visualisation and infographics, both published by Taschen. She is currently getting lost in the history of data visualisation.