The rain has at last subsided here in New England. The resultant high waters have retreated and the cleanup is underway. But the discussion of how sensor technologies can be used to mitigate flood destruction—amid increasing danger worldwide—has only just begun.
Michael J. Pochan, Adjunct Assistant Professor of Entrepreneurship at Carnegie Mellon's Tepper Graduate School of Business responded to my essay of last week to say, “I hope you can find someone in government who understands.” He planned to forward the link to his state senator, who is also a civil engineer.
The Danger Mounts
According to Freshwater in Europe, a publication United Nations Environment Programme, Division of Early Warning and Assessment, flooding is the most common natural hazard in European countries--and climate change is likely to increase its risk across much of the continent.
“Increasing pressure on land for human settlements often leads to a drastic loss of natural riverbed areas and fails to take into account exceptional events,” the report says. “Flood disasters usually result from a lack of appropriate planning of human infrastructure. For example, in the case of the flood and landslide that killed 13 persons in Gondo (Switzerland, 2000), the disaster was caused by a structure for rockfall/avalanche protection which retained [a massive amount] of material before collapsing, unleashing mudflows and rockslides.”
Appropriate planning should, given the resources available today, include monitoring technology. It wouldn’t take many sensors to make a huge difference in a situation like this. Even though, the report says, “other structures such as dams have proven efficient in absorbing surplus rainfall, thus reducing the probability of a large flood.” But how are we monitoring dams?
View To a Spill
It did not surprise me to read at RegulateOnline.org that “sophisticated dam hazard detection and monitoring devices are not in wide use in Sri Lanka,” and that the most common method of dam assessment is visual inspections. But did you know that the same visual inspection methods are in widespread use in New England?
“Right now the only way to keep tabs on what’s happening with all going on is by eyeballing it. People have to report for duty and keep watch,” says Sensors executive editor Stephanie Henkel. That’s because New England dams “are, for the most part, old. The newest ones were built around 1942 or so . . . [and] most of the older ones were built back when water power ran the factories and mills. The water levels behind many are controlled by pulling boards off the tops.”
A Better Vision
Thankfully, not all dam monitoring in the U.S. is done this way. Sensors senior editor Melanie Martella points out that the Army Corps of Engineers is responsible for monitoring 31 large dams in the New England states. But 31 is a small percentage of existing dams, and it doesn’t take a huge dam to wreak devastating damage.
Brainstorming as a group, the editors of Sensors quickly identified a number of technologies that could be put to use to mitigate damage: Strain gauges; load cells; and level, flow, and acoustic sensors—integrated with wireless transmitters—could be retrofitted into existing structures. Sent to a central collection point, the data could be analyzed and unnecessary evacuations could be avoided. Simulation and modeling software could provide a clearer picture of how the structures function under stress and what course water would likely take.
iEMSs the International Environmental Modelling and Software Society (whose third biennial meeting, by the way, takes place July 9–13 in Burlington, Vermont) notes that there are many new methods of hazard analysis, modeling and mapping of natural phenomena. “Nowadays, assessing hazard conditions related to complex natural phenomena increasingly takes advantage of computer-assisted simulations. As a consequence . . . innovative methods (yet not completely standardized) are becoming more prevalent.”
I hope Sensors contributing editor Tom Kevan is right when he says, “eventually, more should come out about what is being done in the Big Easy.” We could use the inspiration—and the reassurance.