Reason for Queensland flooding

[alecstone]

Bob Brown has blamed mining in Qld for the recent floods. Does he think the same for Victoria, Tasmania, Brazil - and anywhere else?

http://myresources.com.au/index.php?option=com_content&view=article&id=2809:brown-blames-miners-for-floods&catid=52:stories&Itemid=113

[Patricia]

So who can Bob Brown blame for the floods many years ago those in the 1800's  ... I think he should have put a little more thought into that statement.   

[Bravus]

This is one reason I'm a member of the Labor party, not the Greens.

Climate change *is*happening. But it's very stupid to ascribe any particular weather event to it.

By the way, we've had a bit over 200 mm of rain so far this January. They had well over 600 in January 1974, almost 40 years ago.

[alecstone]

So who can Bob Brown blame for the floods many years ago those in the 1800's  ... I think he should have put a little more thought into that statement.   

Beats me. It just shows that I have been correct with my thoughts about him for some time now.

[Minx]

One of the weekend papers were mooting the point that it is more likely to be a number of factors
BUT
That a large contributing factor was how full the Dam had been kept
At 190% of capacity ( still trying ot work that math out) it was going to one hell of a controlled release anyway which at this time of the year would have created downstream problems.

I'll see if i can find the article...and link it in later

[mutation]

The reason is that it rained a lot! The usual reason for floods.
I have also heard that the absence of rain can cause droughts!
Who'd a thunk it !
Bob Brown should stick to things he knows! If there is anything he indeed knows!

Mutation

[bambu]

Well that's a relief, Bob Brown has discovered what caused the floods...I was wondering.

"Burning fossil fuels".

Lovely, finally a definitive answer, from the man who'll be virtually running Australia come July this year.

. Close down all the coal-fired power stations immediately!
. Stop all coal mining immediately...lest we be flooded again.

Didn't he say 4 years ago that burning coal and other fossil fuels had caused the massive and permanent drought?

Oh, yes, now I remember, yesterday he explained that as "extreme climate swings" or something.

Lucky Bob's here to tell us these things or we'd never know.

[alecstone]

One of the weekend papers were mooting the point that it is more likely to be a number of factors
BUT
That a large contributing factor was how full the Dam had been kept
At 190% of capacity ( still trying ot work that math out) it was going to one hell of a controlled release anyway which at this time of the year would have created downstream problems.

I'll see if i can find the article...and link it in later

I understand that residents were calling for their water restrictions to be lifted when the level of that dam was getting so high. That, if it had have been done, might have done some good at that time and perhaps saved the flooding?
Bad judgement.

[Redneck]

Not getting into the argument re the dam level as I have no idea of what is its designed holding level is above the 100% before release of the excess. Its a bit of a damned if you do and damned if you  dont release  all above 100%

As far as the general high rainfall and flooding across Australia and lots of other countries I thought this was due to the La Niña effect caused from high ocean temperatures.

Whether the La Niña is from Global Warming I really dont know but this has to fall into the category of an extreme weather event.

[Chris]

So who can Bob Brown blame for the floods many years ago those in the 1800's  ... I think he should have put a little more thought into that statement.   

A flood back in 1867 totally flooded the plains around Windsor, NSW. We took the kids to see the high water mark a few days ago to give them some idea of what was happening in QLD. Back then the river then rose over 20 metres to flood 200 square kilometres or so. Standing up on a *hill* above the river looking out over the river and imagining how much rain must have fallen to make the river rise as far as it did makes you marvel at nature and the havoc it can cause!

I think you're right and perhaps Bob Brown should have kept that idea to himself.

[Bravus]

La Nina/El Nino is a natural cycle that occurs and has occurred forever. The argument is that, since this is a cycle about energy going into and coming out of the oceans, climate change is causing it to be more extreme than usual. As I said, ascribing particular weather events to climate change is stupid: note the name. Climate is the long term pattern of weather, not individual weather events. And certainly extreme weather events, like the 1974 floods, have happened throughout human history.

But those who study climate know that. It's goofs like Bob Brown and maroons in newspaper comment threads (and sometimes on forums) that make dumb comments like 'where's the global warming - it's freezing today'.

This video is helpful in thinking about it: we need to look at the moving averages of climate, not the peaks and troughs.

http://www.bravus.com/blog/?p=1289

I've seen forward climate modelling for Queensland out to 2100. It shows both increased rainfall and increased evaporation, and in the longer run the evaporation wins and the climate gets drier. But note the increased rainfall. If climate change is correct we'll get much deeper droughts in El Nino cycles and much worse floods in La Nina cycles. The evidence is continuing to come in.

[Bravus]

On dam levels, it was actually managed correctly. There has been a *lot* of rain here this year. We started the year in drought, and ended up getting something like 30% more than the annual average, and most of that fell since about October.

Wivenhoe is designed so that it has a little less than half of its total capacity for drinking water storage. The rest - more than half - is for flood mitigation. Once it got back to its 100% drinking water capacity, there was some talk, in the wake of the drought, about letting it sit a, say, 120% in order to have better reserves against the next drought.

In the end it was decided that this was a bad idea with the potential for flooding, and there were major releases from the dam, closing Colleges Crossing for days at a time, to drop it back to 100%. In fact it's Queensland law that if it exceeds 100% they have to drop it back to 100% within a week to protect the city from floods.

The move from 100% to 190% basically happened entirely in the week leading up to the flood. As all the water from Toowoomba was heading down the range, through the Lockyer Valley and toward Wivenhoe Dam, there was an additional 250 mm of rain in a day over the Wivenhoe catchment. They were releasing as hard as they could, but the spillway out couldn't keep up with the flows in.

The flood would definitely have been worse without the dam, because it would all have arrived at once.

But, much as we might like to think we can control it, nature is too much for us. Sometimes it's just going to 'get' us, and all the planning and building in the world won't stop it.

[Bravus]

I wrote my post before finding this newspaper story, but it pretty much bears out my comments: http://www.couriermail.com.au/news/queensland/wivenhoe-dam-eased-the-brisbane-flood/story-e6freoof-1225990080599

[bambu]

When I went to school if a dam had been at 105% the water would've been running over the top.

But hey, they've probably changed the percentage maths since then, they've changed just about everything else.

[Redneck]

When I went to school if a dam had been at 105% the water would've been running over the top.

But hey, they've probably changed the percentage maths since then, they've changed just about everything else.

Perhaps you should read Bravus' post before last!!

It explains it all in reasonably simple terms