Iowa Flooding Could Be An Act of Man, Experts Say

Iowa Flooding Could Be An Act of Man, Experts Say

www.washingtonpost.com

Enshayan, director of an environmental center at the University of Northern Iowa, suspects that this natural disaster wasn't really all that natural. He points out that the heavy rains fell on a landscape radically reengineered by humans. Plowed fields have replaced tallgrass prairies. Fields have been meticulously drained with underground pipes. Streams and creeks have been straightened. Most of the wetlands are gone. Flood plains have been filled and developed.

(visit the link for the full news article)

Sorry HAARP fans, didnt mean to get your hopes up for nothing....

Interesting article though, some things we don't often take into account with regard to flooding. Imagine this same flood taking place 250 years ago, the geography of the time may well have been better equipped to handle such an excess of water.


www.washingtonpost.com
(visit the link for the full news article)

The same could have been said about New Orleans...since you know, it's basically a swamp

The same should have been said about New Orleans. Anytime you attempt to alter a waterway's natural course, particularly in the realm of restricting its floodplain, you're flirting with disaster. As for the development factor, there's a formula we use when we're calculating the runoff expected to reach a roadway pipe culvert from any given watershed drainage area. In the most basic terms, it is a number which you multiply the area times the rainfall intensity times the predicted storm duration time by to determine what percetage of the overall rain falling during an event (generally a 100 year event for the standard culvert pipe sizing design) will reach the culvert. For urban development that value is conservatively taken to range between .6 for general residential and .9 for heavy industrial areas. That basically means they expect 60% of any rainfall in a residential area to flow directly to the culvert without permeating into the ground (it can also be taken to mean that the average residential area is composed of 60% impermeable surfacing like sidewalks, driveways, streets, and buildings, while 40% is lawns, gardens, and native ground.) For comparison, forested land and grasslands fall in the .20 to .40 range while planted crop land comes in at between .40 and .50 range. In layman's terms, that means under ideal conditions undisturbed forest or grassland absorbs twice as much runoff as crop land, 3 times as much as a residential neighborhood, and 4 1/2 times as much runoff as a heavy industrial zone like an airport or paved storage facillity.

I agree with the OP wholeheartedly. However, it also bears repeating that 250 years ago, the Mississippi River's floodplain extended miles past it's current restrained banks. During a major event such as this, the crest wouldn't have been as high, but that would have largely been because the water wasn't restricted from overtopping its natural banks. I'm not well learned on indian tribe locations in the Midwest, but I would wager a guess that there were no permanent villages in the currently flooded areas (unless some of these areas have had earthwork done which has lowered their profiles).

Originally posted by SystemiK

Enshayan, director of an environmental center at the University of Northern Iowa, suspects that this natural disaster wasn't really all that natural. He points out that the heavy rains fell on a landscape radically reengineered by humans. Plowed fields have replaced tallgrass prairies. Fields have been meticulously drained with underground pipes. Streams and creeks have been straightened. Most of the wetlands are gone. Flood plains have been filled and developed.

(visit the link for the full news article)

Yes, straightened streams is the main problem.

If you look at natural streams, you will see a good amount of the ones that go through mountains have S curves to them. This is because the Sun is attracting the water side to side as the Earth circles around it. This keeps the streams from gaining to much speed.

Much like a snowboarder has to pivot side to side to regulate speed, compared to going straight down like a bullet.

We all know there are "water jet cutters" that can cut through metal with just a stream of water. Imagine what a fast stream of water would do to weak soil....

reply to post by SystemiK




on Friday (summer solstice '08) a CNN news segment covered the mississippi flooding...


the white house cut levee appropriations (again, just like in pre-Katrina, LA)


next the Army Corps of Engineers, are busy constructing additinal docks moorings and generally things being built in the river itself that impedes the flow of the river...
it was shown that 3 places up river, where the levees were breached, was likely because the water in the river was backed up some 6feet higher than it should have been--- because the river water did not have a proper outflow...because of the newly built impedements.
All a lack of poor planning and hydrology engineering, and not solely because of the rainfall.


secondly, now this issue confirms what the OP source contends...
that human terraforming is the root cause of flooding,
in the last 30 years parts of Iowa and other sections of the Mississippi has experienced a 100 year flood once and in the last several years has experienced two each 500 year floods...

now 100 & 500 year flood levels happening more than once in a lifetime tells us laymen that something is really out-of-sync, and its not the rainfall which is still within the limits of being 'normal'. therefore the flooding is a matter of river management.
perhaps vast areas of lower land should be operated as silt recovery basins, with the rich topsoil being recovered, and excessive runoff water diverted to these colletion basins so that levees won't be breached so often, and crop lands don't get inundated every couple of years.

using the Nile as an example ofrecovering the silt process but in modern technology processes.
just a thought