« Rob Simmon Joins GalaxyGoo Bloggers | Main | Graphs and the Cognitive Style of Powerpoint »

Historic Mississippi River Channels

A successful visualization is informative, clear, and accurate, and as a result, often beautiful. With my entries I intend to show examples of good data visualization, and describe the elements that go into an elegant design.

Map detail of historic and prehistoric meanders of the Mississippi River by Fisk, 1944

Among the first data visualizations are maps--they're certainly among the most common. This map shows layers of abandoned river channels along the Mississippi in Louisiana. The meanders of the Mississippi are in constant flux, and every 60 years or so—without human intervention—the river changes course, sometimes leaving behind an oxbow lake. Past river channels are indecated by color and texture (stripes). The 3 most recent—1880, 1820, and 1765—are dated from historical records. Cartographers and engineers from the U.S. Army Corps of Engineers reconstructed older channels by analyzing patterns overlying one another in aerial photographs. The high-resolution (this detail is perhaps 1/8th resolution) map is directly labeled, includes geographic referencing, and uses variations in color, text, and line weight to create layers of information. The main story--the constantly changing shape of the river--is immediately apparent, while details emerge with closer study. A legend (visible in the overview below) describes the content, and attributions allow accountability.

Landsat-7 satellite image of the Mississippi River

Although the river is (for now) constrained by the work of the Corps, the patterns of the past remain. A modern satellite image (acquired in 1999) shows the current shape of the Mississippi. Despite the engineering projects of the past century, the shape of fields and roads are constrained by the fossil meanders.

Map overview of historic and prehistoric meanders of the Mississippi River

This map is one of a series published in 1944: Geological Investigation of the Alluvial Valley of the Lower Mississippi River by Fisk. The Landsat data used for the modern image is archived by the Global Land Cover Facility at the University of Mayland.

Perhaps these maps would help people understand that it is wiser to adapt to nature, rather than attempting to adapt nature to our use. I think it's especially relevant as the first anniversary of Hurricane Katrina approaches, and we remember the tragedy in the still-vulnerable city of New Orleans further down the Mississippi.

-Rob Simmon


These maps are beautiful, and clearly convey the dynamic nature of the Mississippi river bed.

The last map made me think of electrons in an orbital, and how an orbital is an area where that electron is likely to be. So, the river has areas where it is likely to flow...just on a much longer timescale than the particles of an atom.

Could you tell me how much the river channel changed as a direct result of the New Madrid Earthquakes of 1811-1812? I heard somewhere it changed the course by 35 miles, but I cannot find it on any of the New Madrid EQ sites. Wikipedia indicates Kentucky Bend was created by the Earthquake (the last major one of the three), but only discusses the land area (~17 sq. mi)