The '500 Year Flooding' Clearly And Simply Explained

Submitted by: 5cats 3 months ago in Science


Having two "once in 500 years" storms in Houston in just 10 years proves AGW is destroying the planet, right?

Well not so much, in fact not at all, says this writer, Charlie Martin of PJ Media. The moniker (which some meteorologists wish wasn't used because it's meaningless) is a rough estimate based on very limited data. It should never be confused with reality. And don't forget about the 'Gamblers Fallacy' too.

By my count (not the article) there's been 4 of these record breaking floods in and around Houston since 1900. They are not 'once every 500 years' and are not harbingers of doom.

"The lesson here — remember there's a quiz on Friday — is that a big storm, in itself, is evidence of nothing more than the fact that there's been a big storm. Not God's wrath, not "instant karma," not climate change. People who say otherwise are trying to sell you something."
There are 28 comments:
Male 1,541
the lesson here is...do not build your friging house on a flood plane and NOT expect it to get flooded.  If you have to...put it up on 12' stilts, and hide it as a "garage" underneath.
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Male 41,572
spanz Lots of towns and cities are on flood plains already, it isn't possible to move them all.
Still, there's plenty of dumb people building where they clearly should not have: the really low places outside of the dikes or other flood controls. Those are hard to move too, they're often the most stubborn people imaginable. Leave them to their regular floods and not one penny of government money for them: they'll move eventually.
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102
5cats Eat shit, fuckface
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Male 569
@_chamberlain A well measured and thoughtful response to someone sharing his opinion.

Grow up
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Male 41,572
toetagmodel2 Thank you for speaking up, it is very nearly all he does, and has been going on for months now.
He's just a sock-puppet though, the actual person is pretty much the same too :p
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Male 4,191
@_chamberlain 
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Male 1,029
spanz The lesson here is do not build in a flood plain - period.  12' stilts won't help you when the water levels rise 20', as they did in parts of Houston.  Look to the government professionals - those who do not profit whether you build or not - for guidance.
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Male 765

Ill just  put this here...
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Male 942
stifler Possibly the best picture ever.
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Male 3,801
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Male 5,419
stifler LOL! I think those two protesters are going to confuse themselves, then wander off to a local diner to figure things out over a couple cups of coffee.
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Male 10,363
Whenever I want good scientific information I go to a website founded by a screenwriter with a drama degree and a jazz guitarist. 
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Male 4,191
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Male 41,572
daegog Oh yeah, nothing like politicizing the suffering of others, am I left? Any excuse to 'punch a Nazi' is a good one!

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102
5cats Go fuck yourself, dumbshit
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Male 4,191
Problem is, people are wasting money rebuilding their homes and lives instead of giving their money directly to Joel Osteen.  If you give you money to Joe, man you will be in a mansion in no time at all, just ask him!
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Male 10,363
Why listen to scientists when there are random blogs on the internet?
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Male 1,029
As someone who professionally works in stormwater management, rainfall intensity frequency analysis is one tool among many for many stormwater related work, including watershed development regulation, flood risk mapping, and stormwater facility design.

It is probability, not certainty.  With most areas of North America having less than 100 years of measured rainfall and water flow records, the uncertainty regarding rarer storm events is much larger.

However, human beings settle near water -along the sea coast, along rivers, and lakes.  To maximize human safety, development should be forcibly restricted to be out of flood risk levels.  The problem will always be: 
  1. humans are already in known flood risk areas and tend to not want to leave
  2. because of its appeal, waterfront land is desirable and because of its scarcity, it is valuable.
  3. humans can't agree on the appropriate level of risk.  There are always those willing to bet with their lives, and there are scum that profit from enabling these risk takers.

It would be logical to say "if your land gets flooded and your [house, city, business, industry] is destroyed, you cannot rebuild it there".  This doesn't happen.  Instead, regulators (who are trying to prevent loss of life and property) are forced to negotiate with politicians and developers to set a limit for future development at a risk-level that is a damn compromise.  We are balancing human lives against money - money will win every time.

So.  We have the reality where folks that have already built next to the water won't move.  Future development is set (in most jurisdictions) at the level of the predicted 1:100 year storm.  In most developed and regulated communities, a 1:100 year storm event will cause flooding with minimal loss of live and property due to scientific watershed management and flood planning.  However, in ocean coastal areas, shit is different.  When we ask "what is the worst that can happen?" the realities for ocean coastal areas are far worse than a typical town by a river.  The reality is, if we truly wanted to minimize risk, we would not permit humans to settle by the ocean.  Letting folks rebuild houses on the ocean shoreline after those houses have been removed by a storm is fucking stupid. Once a new upper limit of storm damage has been set, that should be the lower limit (adding a good buffer for additional safety, of course) for reconstruction and any future development. 

This will never happen in our current reality; and it just exemplifies the stupidity, greed, callousness, and short-term thinking that will doom our species.  No other species on this planet has our gifts.  Imagination, foresight, creativity, the ability to see past the moment all give us the abilities needed to shape our world for the betterment of all of mankind and all the other occupants of this big blue marble.  Except that we don't.  We (collectively) fall to our vices.  We cry at injuries we could have avoided.  We curse the gods at their injustice to us, when its just our own actions or inactions biting us in the ass.  The Tragedy of the Commons.

We will never rise above our petting failings to meet our potential, because its too easy to reach the branch above by stamping on the heads of others.
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Male 8,198
punko Love your thoughts, thanks for sharing.
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Male 13
punko Oh Punko. What a beautifully drafted response to a less than thought out post by 5cats. I love logical reasoning and would take it over conspiracy theories any day. Great job, sir.
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Male 5,419
punko ~gives Punko's ankle a hug~  Punko, methinks you have seen too much as a civil engineer. You'll go nuts if you think about this stuff too much. Ish okay. Have a pistachio.
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Male 1,029
squrlz4ever heh heh the squrlz says "nuts"



and I'm up waaaay past my bed time
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Male 5,419
punko I totally understand where you're coming from on all this, actually. You've spent a career using common sense, logic, and intelligence to protect people from danger and then have to watch as people build housing development directly in the path of hurricanes. You understand the stupidity of it all more than 99.999% of us.
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Male 1,029
squrlz4ever As a consultant, I have worked with municipalities and regulating agencies and I have worked with developers.  One tries to set the rules, the other uses those rules.  Often there are compromises and differences of opinion regarding the application of regulation.
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Male 3,775
punko "As someone who professionally works in stormwater management" i always thought gargoyles were just decorative rainwater spouts.
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Male 1,029
robthelurker We're solid stone during the day.  We get to move after sunset.
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Male 5,419
robthelurker That was good. I think it comes down to moonlighting.
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