Saturday, May 28, 2011

The Mississippi River: Land-Making Machine

[A false color satellite image of the Louisiana Delta; the grey zones are urbanized areas, red areas are vegetated areas, blue is water]

Conceiving of a river as a land-maker, especially the mighty Mississippi, is not necessarily a novel idea.  But the Deleuzian term “land-making machine”, which we first heard coined by brilliant Tulane geographer Richard Campanella, is particularly powerful and we love it.

Let’s first briefly consider Deleuze and Guattari’s machine:
A machine may be defined as a system of interruptions or breaks.  These breaks should in no way be considered as a separation from reality; rather, they operate along lines that vary according to whatever aspect of them we are considering.  Every machine, in the first place, is related to a continual material flow that it cuts into.

That seems pretty clear, and directly relevant and if you want to read more excerpts can be found here.  It should be mentioned that Deleuze and Guattari’s machine is layered, relative, and causal.  Like any nerdy designer, we could spend the next 10,000 words misunderstanding and misappropriating it to justify our positions.  But let’s move on to talk about mud.  The point is, Campanella’s “land-making machine” [LMM] is an awesome term, and that’s how we’ll refer to the Mississippi River for the foreseeable future.

The LMM built the Louisiana Delta in the last 5,000 years with the massive loads of slurry it transported from the heart of the continent to the Gulf of Mexico.  It is estimated that before 1930 this load was about 400 million tons of sediment per year.  These estimates are variable with a large margin for error given inconsistency in testing methods and locations.  Nonetheless, when compared with post-1930 numbers they are instructive.  Since 1930 this load had decreased significantly, with estimates ranging from 145 million to 230 million tons per year.  This load reduction is attributable in equal parts to the revetments, levees, and enhanced agricultural practices that reduce the amount of sediment available, and the dams that trap sediment along the tributary rivers.
[historical deltas of the Land Making Machine; today 2/3 of the flow and sediment goes through the "Bird Foot Delta", 1/3 through the Atchafalaya River; image source Texas A & M Department of Oceanography]

[map of 1874 flood on the Mississippi; floods like this contributed to the imperative to build flood control measures up and down the river, culminating in the 1928 Flood Control Act]

Despite this massive reduction, the LMM still discharges a sediment load that approximates that of the next six sediment-iest rivers in the United States combined.  Most of this sediment is no longer used to continuously build the delta.  Rather, thanks to the 1830’s engineering of Capt. James Eads, it is shot out into the Gulf of Mexico.  As a result of his innovative jetty system, and the upstream flood control measures put in place a century later, a land mass approximately the size of Delaware has been lost from the Louisiana coast since the 1930’s.  But the potential of the LMM remains.

The massive potentiality of the LMM is the source of serious speculation, academic proposals, and pilot projects.  To make this notion visceral let’s consider the case of Cubit’s Gap, a major subdelta of the LMM.  The gap formed in 1862 after an oyster fisherman (Cubit) and his daughters excavated a small ditch in the natural levee between the Mississippi River and the oyster-rich Bay Ronde in order to portage their fishing boat more easily.  The following spring floodwater poured through, gouging a crevasse and depositing sediment.  Six years later the crevasse was 2,427 feet wide [1].  By 1940 a landmass larger than New Orleans had been created and the Bay Ronde had completely disappeared.  Today, the Cubits Gap subdelta is 40,000 acres of national wildlife refuge and is quickly subsiding back into the Gulf of Mexico.
[this map from 1839 predates the handiwork of Cubit, his daughters and the LMM; the Bay Ronde can be seen in the middle of the map]

 [this map from 1922 shows the resulting subdelta; source of images and account of Cubits Gap is Geoscience and Man, Volume XVI, The Mississippi River Delta, Legal-Geomorphologic Evaluation of Historic Shoreline Changes, David Joel Morgan.  School of Geoscience, Louisiana State University.]

The incredible dynamism of the geology and hydrology rolled together into a Land-Making Machine, paired with the image of an old fisherman and his daughters tugging a tiny fishing skiff is beautiful.  It also brings up interesting questions of agency.  The causal relations between army engineers, old fishermen and their daughters, and the Land-Making Machine itself smashed together here at the borderlands of intentionality suggest a richer, wilder concept of urbanization, inhabitation and infrastructure is desired. 

Massive engineering projects by corporations and bureaucracies may very well be key to working with the LMM.  Or perhaps we just need more nomads, surveyors, fishermen, and farmers.  Very likely, it’s some combination of both.  Such is the American landscape- MORE EVERYTHING!
[pelicans in Cubits Gap]

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