Wednesday, November 12, 2008

The Rains Came, But How Much Per Square Foot?

In the previous post I shared photos of fabulous fall trees. It's been beautiful here. Weather has been dry and cool and generally gorgeous! Yesterday, however, all that changed. It rained. In fact, it rained a ton. Yes, we needed the lovely rains. Really needed them!

When I got up this morning I checked the rain gauge. It had rained (in the past 24 hour period) 4.4 inches. I wonder how many gallons that equals per square foot. Anyone out there, of the super scientific brain sort who can let me know the calculations for that? Oh, on second thought, just figure it out for me please and let me know.

I suppose it's something like,
"x inches of rain times y hours (times 1/2 acre--more or less) times some unknown formulaic equation I've never heard of divided by the direction and velocity of the wind, minus all the leaves that fell in the process and whether it was light outside or dark at the time the rains actually fell." I'm sure quantum mechanics of rain calculations covers all that, doesn't it?

Oh, and I suppose that when the rain was falling at "sprinkle speed vs. torrential speed" could possibly complicate the equation a bit. Or not. Anyway, any of you egg-heads out there want to attempt to esplain it to the confounded and dimwitted writer of this post? I'd love to know. Ser'ously.

Oh, and the Weather Channel, or some other weather entity prognosticated there were flooding possibilities for this neck of the woods. Or possibly south of here. Since water flows down, it's probably south of here. Besides. I do live on a hill. I have watched great quantities (i.e., gallons) of water flow across my yard, puddle at the middle landing on my steps out the front door, and across the driveway. That's not counting the stream that flows down my back yard and into the wilderness behind our property. (The stream only exists in extremely heavy downpours--like the times it's rained about 3 to 4 inches in a hour. Yes. I did say, 3 to 4 inches in one hour!) And/or on those occasions when it's rained multi inches of rain over several days.

STILL: I do love rainy days! Let me amend that. I do love rainy days when the water DOES NOT seep into my downstairs because the ground is saturated. AND when I can stay inside and be cozy. And dry.

I even like watching the lightening and stormy clouds as they contort and frolic across the sky. Love clouds. EXCEPT for when danger is imminent. But I digress.

I want to know how to compute the number of gallons of water that falls/fell per square foot. Oh, yeah. You have to count the water that fell ON the house, and cascaded down the roof into a huge waterfall close to the front door. And maybe that that also poured off the back of the house? The sides? Or rather ends where there's no sloping roof? Maybe it's just too complicated to figure it out. *SIGH*


Debby said...

Obviously your readers are not mathematicians either. There actually is a method to determine the amount of rain that comes of a roof. I believe you take the amount of rain that has fallen, and multiply it by the size of the roof. Understand that it might be easier to calculate if you take a pan that has a foot square measurement to measure the initial rainfall, instead of figuring the area of your roof in square inches. That would be my suggestion.

Pencil Writer said...

Hmmmm. A foot square pan . . . probably a much easier solution to learning the answer than the extended mathification of all the variables, times a bunch of nonsense, plus a little fun. But I like the idea of the square foot pan. Yes. But how deep would the pan need to be?

jeanie said...

Your rain gauge measures in how much water falls on the surface area of the gauge.

Therefore - one inch of water is one inch in depth across the area the gauge covers, and we assume it therefore is one inch across the whole area.

Volume is calculated at depth x area, but because you are all imperial and I have no ideas about that...

Here is a link that works it out in handy metric!!

Ah - here is one in metric for you:

jeanie said...

oops - the second one I meant imperial!!