Oct 19, 2011

How many billions of billions?

Question:

How many billions of gallons per second of water are discharging into Lake Okeechobee because of the recent deluge on the Kissimmee River?

Answer: Wrong question!

Can you see how this year was tracking close
to the drought year of 2007 ...

Then came the October rains!

The first step in hydrology is getting the units right.

Numbers don’t mean anything unless we can put them within a framework that we can compare them to something we know.


The graph above shows the rate of water flow in the Kissimmee River for this year (to date) and previous years of note relative to the U.S. Geological Survey standard – cubic feet per second -- but goes the additional step of adding on the more layman-assessable Empire State Buildings per day, Fenway Parks (as filled up to the 37.5 ft tall Green Monster), and Olympic-sized swimming pools per second units.

So many billions of gallons or thousands of cubic feet will fool you every time because those numbers are hard to visualize whereas converting it relative to a two-acre baseball field or a 1,250 ft tall skyscraper immediately paints a clearer hydrologic view.

15,000 cubic feet per second equals
12 Empire State Buildings per day

Then comes the eureka moment:

“Wow, that is a lot of water!”

4 comments:

Robert V. Sobczak said...

Note: I had to make a minor correction on my swimming-pool math (I forgot to carry the one.)

swampbuggy said...

I was checking the math but took it in a different direction.
According to the Empire State Bldg. website the building is about 37 million cubic feet. At 15,000 cfs you could fill the building in about 40 minutes.

Daryl Ritchison said...

Plus another tropical system or moisture may be pulled up next week from a system currently in the Caribbean. Could be an October that won't soon be forgotten.

Robert V. Sobczak said...

I was out in the swamp for a bit today: It's deep!