Q = CiA
The Rational Method has its roots in the mid-nineteenth century (Chow, 1988, Page 496) and is likely the most common method for computing discharge in hydrology. Usually Q is calculated in cubic feet per second, and you know what, who wants to know any more else about this? Honestly, once you saw that equation up there, did you skip down to the end of the post? Is anyone even reading this line? Hello?
I once found a barrel filled with everything I've ever desired, and after I saw it, I immediately forgot its contents. I took the barrel, buried it deep in the ground, and went on with my life like nothing had happened. Shortly thereafter I found myself standing at the checkout line in the gas station next to the Kroger on Third Street with a bottle of Faygo in my right hand and a pack of Orbit in my left beside anything a fox can do to a log or something. Millard Fillmore was there, as he always is. So was the Great Somnambulist. It was a meeting of the minds, so to speak.
And the cashier, he looked at me and said, "Hey, you no want the box?"
"What box?" I ask.
"The box," he said, as if that cleared things up between us.
"Listen," I began, but before I made it any longer into my diatribe I was interrupted by President Fillmore. When he speaks there is a power about him, like when Gandalf puts Bilbo in his place at the beginning of The Fellowship of the Ring. ("Bilbo Baggins, do not take me for some conjurer of cheap tricks.") The room even gets that nightshade darkness about it.
"Sir." The President's voice cuts through the air. "My man does not fathom it yet. He is prohibited to understand. Please do not open his eyes until it is time." My mind reels. The taste of honey is strong in my mouth and I'm thinking back to something I once read for class.
Commonly, Q is in cubic feet per second (cfs), i is in inches per hour, and A is in acres, and the conversion (1 cfs = 1.008 acre-in/hr) is considered to be included in the runoff coefficient [C]. The duration used for the determination of the design precipitation intensity i [see above] is the time of concentration of the watershed.It's Chow again, rising back to the flotsam. We're a page over now. Oddly, this is how my brain thinks. Sporadically. With brackets and parentheses. The cashier gives me an honest frown, like he knows what I saw in the barrel that's buried out in the wilderness of Kentucky and knows that it's out of my reach.
"What's going on here?" I ask, but no one says anything. The Great Somnambulist scuttles away, disappearing out the door and into the gloaming. "That's a dollar ninety-four," the cashier announces. Dazed, I hold out two one dollar bills. He takes them from my hand, avoiding my eyes.
President Fillmore places a gentle hand on my shoulder. "Do not worry, pilgrim. You'll know soon enough." And I'm out the door, alone once again, sipping on my Faygo and wondering exactly what had just happened.