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Is a flash flood due to accumulation? - Lasaraleen

"More people die yearly in floods (127 on average) than by lightning (73), tornadoes (65), or hurricanes (16)." Is this just a U.S. figure? If so it should be labeled as such. It seems mighty low for worldwide. - Ace of Sevens

Also, it should be stated what year those figures are for. Populations numbers change, etc.

~ender 2005-07-22 15:44:MST

Peter Shearan 14:50, 20 August 2006 (UTC)Reply[reply]

Who said it was? I don't think it makes a lot of sense to have a section for each country, though. I'll update the article. -- Moondigger 15:15, 20 August 2006 (UTC)Reply[reply]

Thank you to whomever changed the caption to remove the reference to millions of years to carve Antelope Canyon. My take is that it is in the time range of 10,000 years, but I don't REALLY have a source that is quite so specific. So, thank you for making it unspecified, which I think is fairest. Ratagonia 06:14, 8 November 2006 (UTC)Reply[reply]

It's not a matter of "fair." It's a matter of accuracy, and "millions of years" is correct. I'm changing it back. -- Moondigger 16:47, 8 November 2006 (UTC)Reply[reply]

You have a source? Please state it. A source for circa 10,000 years: Ranney, Wayne. Carving the Grand Canyon.Grand Canyon Association, 2005. Grand Canyon AZ. ISBN: 0-938216-82-1 Ratagonia 06:54, 9 November 2006 (UTC)Reply[reply]

1. The caption refers to Antelope Canyon, a slot canyon near Page, Arizona -- not the Grand Canyon, which is what your reference addresses.

2. Taking up your reference anyway -- most geological references I have read indicate the Grand Canyon formed over the course of millions of years. The idea that it was "carved" in 10,000 years is generally supported only by young-earth creationist literature. I do not know if Wayne Ranney is a YEC, and will not waste the time doing the research. However I will say that his theory is at odds with the vast majority of geological literature about canyon formation.

3. My Antelope Canyon-specific source is the Navajo tour guide who explained the history of the canyon when I toured there in 2005.

4. A simple google search turns up a few references indicating "millions of years" as a rough estimate of the time it takes for slot canyon formation. Even if such references were off by an order of magnitude (hypothetically speaking -- there's no credible evidence that it's off), it would still be "hundreds of thousands" of years, not "10,000."

5. The Wikipedia article for "slot canyon" specifies an even longer estimate of "100-200 million years" for slot canyon formation. That estimate was not written by me.

Comment: Per #4, if this estimate (100-200 million years) is off by two orders of magnitude, the caption would still be accurate as "millions of years," -- it would have to be off by three orders of magnitude before we would be forced to change the caption to "hundreds of thousands" of years.

-- Moondigger 15:36, 13 November 2006 (UTC)Reply[reply]

Please see WP:RS. If you can come up with a reliable source, please do so. So far - none. I also cannot find a source that indicates on the order of 100,000 years, so will not put that in either. But:

If you'd like, we can discuss it, but this falls into the realm of original research, rather than a citable source. Mr. Ranney is a staff geologist with the GCNHA, not a Young Earth Conjecturist. Your Antelope Canyon tour guide is not a citable source. The Wikipedia article on slot canyons is not a citable source.

For the two terms I was a geophysics major, this was the kind of things we figured out. What is the erosion rate in antelope canyon? How deep is it? How big is it? For it to be millions of years old, the erosion rate would have to be laughably small. It is a small feature. There may have been canyons like it in the area 1 million years ago, but it is implausible that the feature we call Antelope Canyon today was at all similar to what it is today.

190 million years ago, this area (the Colorado Plateau) was a vast basin west of a very high mountain range, slowly filling with sand which became the Navajo Sandstone. After that, the Navajo was buried by more sediments, pushed down into the earth and cooked, etc. etc. While geological changes take place over vast times, even on a geologic timescale, hundreds of millions of years is a long time. Small (100's of meters) features like Antelope Canyon and other slot canyons are transitory features. Etc. Ratagonia 00:11, 8 January 2007 (UTC)Reply[reply]

I'm fine with not stating any estimated timeframe, given the lack of citable sources. I do object to very short estimates such as 10,000 or 100,000 years, especially when the source you cited doesn't address Antelope Canyon in the first place. As I said before, I do not know or care if Wayne Ranney is a YEC; his 10,000 year estimate for the formation of the Grand Canyon is orders of magnitude shorter than any other citable reference I have found, and only matches within a single order of magnitude the theories of Young Earthers. -- Moondigger 22:14, 31 January 2007 (UTC)Reply[reply]

One more comment, though. "Millions of years" is not an unreasonable estimate. It covers the entire range from one million to one billion years, and at least gives an idea that such formations are not built in a very short timeframe. Ten thousand years is laughably short on a geologic timescale, especially since the primary weathering agents in Antelope Canyon are water and water-driven sand. Rainfall is scarce in that area of Arizona and Utah and has been scarce for geologically long periods of time. One could reasonably argue that the Grand Canyon formed faster than Antelope Canyon because it had the Colorado River to act as a constant weathering agent, whereas Antelope Canyon gets enough rainfall to cause a flood only very rarely. - Moondigger 22:23, 31 January 2007 (UTC)Reply[reply]

These Reuters links seem to go out of date, therefore are not appropriate to list. Please don't. Ratagonia 22:09, 2 February 2007 (UTC)Reply[reply]

bebo.com —Preceding unsigned comment added by 78.144.223.4 (talk) 14:06, 18 January 2009 (UTC)Reply[reply]

Is the gobi picture really a flash flood? Or is it just runoff from a minor storm? —Preceding unsigned comment added by 8.227.14.211 (talk • contribs) 18:19, 18 January 2010 (UTC)Reply[reply]

The photo was produced by User:Qfl247 who lists spending extended time in the Gobi. You might ask him or her on their talk page. —EncMstr (talk) 20:39, 18 January 2010 (UTC)Reply[reply]

OMG OMG! Arjun Raj 699 (talk) 14:40, 28 October 2017 (UTC)Reply[reply]

I think the article needs a brief discussion of the speed at which flash floods can move. I'm having trouble finding anything solid; the only source I've found so far gives "about 67 mph" as a top speed. Anything described as "about" that isn't rounded to the nearest 5 mph seems suspect to me, and since it's the only source I've found, I'm not willing to use it in the article. Does anyone have a good source on this? Dismalscholar (talk) 16:56, 1 May 2011 (UTC)Reply[reply]

First of all, there is no meaningful way to generalize the speed of a flash flood. Even if there were, it would be misleading. Speed is dependent on the slope of the ground, amount of water, type of debris in the water, ability for water to spread out or be concentrated, type of vegetation, texture of surface, etc., etc. —EncMstr (talk) 17:42, 1 May 2011 (UTC)Reply[reply]

I timed the front of a flash flood down a 20 mile stretch of the Fremont River in Utah, it moved at 12mph. I think it very much depends on the volume of water and the topography of the river, similar floods seen in the smaller streams above the Fremont have clearly been moving much faster at that point. Bob Palin (talk) 18:36, 12 January 2013 (UTC)Reply[reply]

Concur. Ratagonia (talk) 20:32, 1 May 2011 (UTC)Reply[reply]

A flash flood is a very sudden unexpected flood. The mention of 6 hours of rain being classed as a flash flood would incorporate nearly every flood event I have ever heard of. The original meaning of a flash flood was for something like a dam wall bursting or a wall of water flowing down a river to a location that has not had rain. The resuling wall of water will cause flash flooding downstream. I would reduce this time from hours to seconds. —Preceding unsigned comment added by Whatdoctor (talk • contribs) 22:37, 10 May 2011 (UTC)Reply[reply]

I live in Dublin, OH, and the Dublin Platypus Day Flood of 2011 (yeah, I know you've never heard of it) took 5 days to reach its crest. A flash flood reaches its crest within 6 hour of the triggering event. Also, Flash flooding is not always on/in/near any stream of flowing water. Flash floods can be areal, river, any number of coastal/lakeshore kinds, storm drain backup, levee failure, or other.  --Bowser the Storm Tracker  ^{Chat Me Up} 00:35, 15 August 2011 (UTC)Reply[reply]

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We already have a list article, List of flash floods, which is almost identical with the list of flash floods here. Looking at WP:CSC, my take is that we should keep only the list article (which we could link to with a See also at the top of the impact section) and the list should be restricted to flash floods sufficiently notable that they have, or should have, their own Wikipedia article. Does this sound right? --Kent G. Budge (talk) 00:01, 18 July 2021 (UTC)Reply[reply]

Going ahead with this -- removing all items that don't have their own Wiki article. --Kent G. Budge (talk) 19:47, 12 March 2022 (UTC)Reply[reply]

Are flash floods dangerous? 2601:1C0:4D7F:FC70:70FF:ACFD:A593:F2BC (talk) 23:35, 20 November 2021 (UTC)Reply[reply]

A flash flood is a rapid flooding of low-lying areas: washes, rivers, dry lakes and depressions. It may be caused by heavy rain associated with a severe thunderstorm, hurricane, tropical storm, or meltwater from ice o 120.29.78.247 (talk) 15:03, 22 March 2022 (UTC)Reply[reply]

As currently written this article focuses almost entirely on events and references from the USA. Itinerantlife (talk) 15:12, 21 October 2022 (UTC)Reply[reply]

Flash floods 196.192.88.46 (talk) 17:43, 19 January 2023 (UTC)Reply[reply]