Flood stats are hard to fathom
Published 12:23 am Sunday, May 15, 2011
Is the spectacle we see unfolding before us in the Mississippi River something that is becoming more and more commonplace?
Somewhere around the middle of last week as the floodwaters topped the previously known records in Natchez, I started wondering that and probably a few dozen more questions about the Mississippi River.
As someone who spends a good bit of my time looking at numbers — running a business can make that necessary — the gargantuan amount of water passing the windows of our community is utterly staggering.
The current flow rate is more than 2 million cubic feet per second — per second!
In no time those numbers start getting crazy high. We’re talking national debt realms.
At a rate of 2 million cubic feet per second, the Big Muddy is pushing 120 million cubic feet every minute or 7.2 billion cubic feet every hour.
In a 24-hour period, that’s 172.8 billion cubic feet of Mississippi River water gunning past. In a week, the number hits the trillions — 1.2 trillion to be exact.
Given the weight and power the water carries with it, the Mississippi bloated by record floodwaters is a snarling, powerful beast barging its way south.
Man has done its best to control the massively strong current of the Mississippi and in the days ahead we’ll see how well that works in some places and doesn’t in others.
The Great Flood of 2011 has many of us fascinated and scratching our heads a bit, too.
I heard someone last week ask, “Is this a 500-year-flood or is it more like a 1,000-year-flood?”
My pea-brained logic told me, well if it hasn’t flooded like this in the last 100 years, that must mean it’s at least a “100-year-flood.”
How wrong I was, though.
The description of “100-year flood” or “500-year flood” is a little misleading. The description is really more statistical in nature.
A 100-year flood is a flood that, statistically speaking, has a one in 100 chance of being equaled or exceeded in a given year.
A 500-year flood is one with a 1 in 500 chance of happening in a given year.
The crazy thing — the thing that will drive those of us who don’t like statistics in particular — is that a given spot on a map could experience two “500-year floods” back-to-back.
Having one flood doesn’t protect an area from another flood a short time later.
That’s not exactly reassuring for us now.
We want to understand this whole thing. We want to be able to predict it, label it and understand it.
We want to be able to say “Yes, it’s flooding here, but it won’t happen again for a really, really long time.”
But we’re talking about an act of God that is out of the hands of mortal man.
We cannot understand it fully or predict it completely. We just need to do the best we can to overcome the complications it brings and learn life lessons from the experience.
Kevin Cooper is publisher of The Natchez Democrat. He can be reached at 601-445-3539 or kevin.cooper@natchezdemocrat.com.