On Jan 7, 2009, at 15:25, Neal Hammon wrote:
> Bill:
>
> With paper, and assuming no ground absorption, it appears that one
> inch of rain per acre gives us 27,154.29 gallons of water. Am I
> close? Neal
I'd have to go through the computations, again. That's the beauty of
it... it's a pain, it takes time, and it yields a number which isn't
easily remembered. Lessee, here's the logic I usually use (with some
approximations):
1 sq. mile 5280 ft * 5280 ft 1 ft
1 inch-acre * ---------- * ----------------- * -----
640 acres 1 sq mile 12 in
puts everything into cubic feet, say AAA cu. ft.
There are now 2 paths: approximate 1 cubic ft by 60 lbs of water,
remember 'a pint is a pound the world round', and hence get
60 lbs water 1 pint 1 gallon
AAA cu. ft * ------------ * ---------- * --------
1 cu. ft 1 lb water 8 pints
or convert through metric and remember conversions from the grocery
store:
3 m 3 m 3 m 1000 l. 4 gallons
AAA cu. ft * ----- * ----- * ----- * ------ * --------
10 ft 10 ft 10 ft cu. m. 15 l.
this is a bit low, because there are slighly more than 3 meters in 10
feet.
All the canceling of common factors and little multiplication
approximations are the fun part. (Remember that 'fun' is a relative
statement, just like 'aunt martha'.)
I'm not going to multiply it out, because I'll then remember the
number and will need to think of some other computation to do while
driving.
Bill
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