Comments on: Mojave Desert runoff event | 3 Sept 2007 | Adelanto, Calif

By: bapyou

bapyou — Sun, 15 Feb 2009 06:42:09 +0000

Hello. This is a …
o. This is a reply to your comment from 8 months ago.

I have a new memeory card that is 4GB. I have several of them now.

Also, if you haven’t figured it out by now, to get the best quality video using your Canon A630, be certain that the camera is set on STANDARD video.

By: bapyou

bapyou — Sun, 15 Feb 2009 06:42:09 +0000

Of course, desert …
Of course, desert ephemeral flows vary in both space and time; variation with time is the very essence of the term ephemeral. Calculating discharge would vary depending on where along the flowing stream channel you decide to measure.

Hey, thank you again for your comment. I always enjoy engaging in a discussion of topics realted to hydrology and/or geomorphology. There aren’t many persons with whom I can do so.

By: bapyou

bapyou — Sun, 15 Feb 2009 06:42:09 +0000

How about this for …
How about this for a crude estimate of discharge on the road at the beginning of the video:

The flow appears to be advancing at a rate of about 1/2 foot per second. Let’s use that for a velocity.

For depth I would guess that it was no more than six inches deep. And the width of flow…let’s say about 10 feet?

So using a cross-sectional area of 5 feet, and a velocity of 0.5 ft/sec inserted into the equation of continuity (Q = AV) that works out to about 2 to 3 cusecs.

By: bapyou

bapyou — Sun, 15 Feb 2009 06:42:09 +0000

The big flow shown …
The big flow shown at the beginning of the video went right into a housing development, which made me wonder: What sort of hydrologic/geomorphologic study was or was not done before the development was constructed? Apparently, they’ve built homes right in the path of an ephemeral desert wash. Not a good idea. This runoff event appeared to be relatively modest. What if a real gully-washer of a thunderstorm happened at this location? That housing development could be in for some serious trouble.

By: bapyou

bapyou — Sun, 15 Feb 2009 06:42:09 +0000

Hello. Thank you …
o. Thank you for the comment. You’re an aspiring hydrologist? Excellent career choice.

As for the rate of discharge, I couldn’t be certain at all. Obviously, at the begining of the video there is a greater discharge flowing along the road than that which you see in the upper parts of the stream later in the video. Where the stream is very shallow in the “natural” reach shown, the discharge was less than 1 cfs for sure.

By: georellen

georellen — Sun, 15 Feb 2009 06:42:09 +0000

This is really cool …
This is really cool! thanks for posting!
I’m an aspiring hydrologist. I’m curious, what would you guess the rate of discharge is for this event?

By: bapyou

bapyou — Sun, 15 Feb 2009 06:42:09 +0000

If such things …
If such things interest you, David, pick up a book on geomorhpology, or, more specifically, fluvial geomorhpology. (The term ‘fluvial’ means stream-related.) Also, there are books that focus specifically on desert geomorhpology. If you’re interested, I can reccommend some titles.

By: bapyou

bapyou — Sun, 15 Feb 2009 06:42:09 +0000

Hello David.

” …
o David.

“did you just come upon this event by chance?”

Yes. I was out for a drive in the desert last September when I saw this water flowing down Adelanto Road. What I don’t show in this video is a subdivision, the entrance to which was flooded above the curbing. Seeing that water in the subdivision made me wonder whether the developers of the subdivision had done a proper hydrological study of the site. Of course, this is just speculation on my part.

By: davidsquall351

davidsquall351 — Sun, 15 Feb 2009 06:42:09 +0000

thaks for …
thaks for explaining this. i wouldnt know what a ehpemeral stream was.
did you just come upon this event by chance?

By: undercoverjedi

undercoverjedi — Sun, 15 Feb 2009 06:42:09 +0000

That looks …
That looks familliar!