Re: population growth & physics ed

["B. Esser" <besser@creighton.edu>]

On Thu, 18 Jul 1996, Dave Baum - Drew University Physics Dept. wrote:

> Well, I agree.  I grew up where there are no floods, few tornados, no hurricanes, the occasional small eqrthquake, but we get an average of 200+ inches of snow.
> My point was in risk assessment.  Ther is some non-zero, but also non-unity
> probablility that your home will be destroyed by a hurricane.
>
> There is a 100% probability that these houses will be flooded out.

Many years ago I purchased some land which is situated between the Platte 
river to the north and Skull creek to the south near Linwood NE.  Before 
completing the purchase I asked the locals, checked with the county ASCS 
office, checked the nearby weekly papers and determined that within 
"recorded" and "remembered" history neither the river or the creek had 
ever flooded this particular piece of land.

A few years ago in response to some developers/landowners upstream on 
Skull creek, the levy was modified.  The width of the channel between the 
banks of  the levy was changed from 100 ft to 200 ft and all bridges were 
reconstructed to accomodate that change.  Of course, for those of us 
downstream the distance between levy's stayed at 80-100 ft.  Now there 
exists a great funnel effect as a stream confined to a 200 ft wide 
channel narrows to a 100 ft wide channel at a bend in the creek about 3 
miles from my place.  
Yes, i now have a 100% flood probability whenever the hills to the south 
of us gets more than 4-5 inches of rain.  In fact three weeks ago a 9 
inch downpour created a nice flood here, wiping out the levee, the crops 
and leaving about 12-18  inches of silt on  the land (along with about 
200 trees limbs).  While moving the silt around i had a lot of time to 
think about topsoil erosion (mentioned in an earlier post), coefficients 
of friction (yes my JD can get stuck and yes keeping it cranking as the 
locals say can help), and wondering how many others "built" on solid 
ground only to find that politics and a dozer has made their ground the 
new flood plain.

Bruce Esser
Physics Teacher                   Something witty
Marian High School                     Should go here
Omaha NE
http://marian.creighton.edu