Friday, 7 March 2008

a flood of new experimental data

via /.:
The [Glen Canyon] Dam is releasing four to five times its normal amount of water over the course of a three day artificial flood [in the Grand Canyon]. Scientists are conducting this massive experiment in order to document and better understand the complex relation of the aquatic habitats, natural floods, and the sediment they bring. Floods no longer bring sediment to these parts of the canyon as the Dam keeps it locked up and released in small, drawn out intervals. The Dam prevents the floods from bringing the sediments into replenish the sandbars and allow the river to maintain its warm, murky habitat rather than a cool, clear one. It is thought that this cool clear environment brought on by the dam is responsible for helping to extinguish 4 species of fish and push 2 more towards the brink. It is hoped that this terra-reformation experiment will positively impact the habitat and fish populations, warranting further artificial floods at an increased rate of every one to two years rather than the time span between the two previous floods and this one of 8 and 4 years.
It is delightful to hear that river managers are taking seriously the notion of planned extreme events.

One of the great joys of my early education was the scale river model in Mr. Lind's seventh grade science class. The table, perhaps one meter wide and two in length, with one end a hand or two higher than the other, was filled with gravelly sand. At the higher end, a faucet. At the lower, a bucket. Much like the ones used at the Waterways Experiment Station, this scale model demonstrates (or simulates) alluvial processes such as the formation of oxbows. This was one of my favorite experiences as a seventh grader, so I have a soft spot in my heart for WES.

More recently, I came across "The Art of Scientific Precision: River Research in the United States Army Corps of Engineers to 1945" by Martin Reuss [Technology and Culture 40.2 (1999) 292-323]. Reuss gives a good technical history of river research, contextualizing the scientific and technical challenges in a broader landscape of national politics and inter-agency scuffles. Though the work misses the larger context of culture, it still might help to fill in gaps left by other works. Reading at times like a biography of the Waterways Experiment Station, Reuss outlines the reasons for its inception, the details of its founding, and its relatively successful early history. The Army Corps of Engineers, the body responsible (along with the Bureau of Reclamation) for most large waterways engineering projects in the US, had a history of extraordinary successes and a few catastrophic and very public failures (Katrina is merely the most recent). The gap between theory and practice in hydraulic engineering was more of a chasm, and certain strong-willed bureaucrats clashed over what to do about it. The science was hard, the engineering involved too many variables, too much space, and too long a time span. "Hans Albert Einstein is reported to have said that his more famous father, Albert, was interested in river mechanics, but after careful consideration opted for the simpler aspects of physics" (322).

Many histories of new fields or agencies have an element of the "lone, neglected genius" and Reuss follows the script, which has the advantage of preventing him from slipping into technical inanity until the end of the paper. In any case, after a turf battle of sorts with the Bureau of Standards, a division of the Department of Commerce (which was interested in rivers for obvious reasons), the Waterways Experiment Station was formed (and words like "hydraulic," "research," and "laboratory" are missing from the title as a result of the politics).

One of the most fascinating lessons of ecology over the past century is the need for periodic medium-sized disruption to maintain overall system stability--and prevent catastrophe. Massive wildfires followed decades of fire control policy. Now foresters set small blazes to clear the forest floor of excess debris. Dammed rivers died without occasional floods to refresh their supply of nutrient-bearing silt and irregular shoals and sandbars. It stands to reason that smaller, planned floods will help to correct this deficit. The question now is, what else have we missed?

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