Bishop Hill A report from Brisbane
Jan 12, 2011 Climate: other Greens Reader Grant left this in the comments to the previous post:
I live in Brisbane on high ground. Brisbane is flooding and up to 20,000 properties will be under water by tomorrow. Our major dam is at 190% capacity and they had to release 600,000 megalitres yesterday to just keep it at that. 75% of Queensland has been declared a flood disaster area and that is roughly half a million square kilometres. This is not a disaster anywhere near the order of magnitude of the Boxing Day tsunami or the Haiti earthquake. However people have died and more bodies will be found when search and rescue can find them. They have been swept away.
Delingpole’s article (not written by him) was incorrect in many aspects. Certainly more dams should have been built even if they might have put pressure on the rare lesser spotted tadpole in the catchment area. The Greens of course and local landowners put an end to that and will continue to do so as long as the Greens exist. However more dams wouldn’t have stopped the current severe floods unless an unrealistic number had been built. They may have saved some properties but the rivers do need to flow.
Eventually the waters will recede, bodies will be buried, clean-ups will commence, money will be paid out or borrowed and people will start again. Strangely however, Australian climate scientists have been noticeably absent in the media during these floods. Not on television, newspaper or radio. Not a peep. They were queuing up to get their earnest dials on TV after the hot summer and tragic deaths of the Victorian bushfires. Solemn looks, hand clasping, oh dear, if you’d only listened to us. Of course, they’d predicted this warming and were more than happy to tell us about it.
So have their precipitation predictions had anything to do with their recent camera shyness? Possibly. Here’s Prof Tim Flannery in New Scientist in 2007 –
Over the past 50 years southern Australia has lost about 20 per cent of its rainfall, and one cause is almost certainly global warming. Similar losses have been experienced in eastern Australia, and although the science is less certain it is probable that global warming is behind these losses too........Desalination plants can provide insurance against drought. In Adelaide, Sydney and Brisbane, water supplies are so low they need desalinated water urgently, possibly in as little as 18 months. Of course, these plants should be supplied by zero-carbon power sources
Here’s Dr David Jones from the Australian Bureau of Meteorology in 2008 –
IT MAY be time to stop describing south-eastern Australia as gripped by drought and instead accept the extreme dry as permanent… “Perhaps we should call it our new climate,” said the Bureau of Meteorology’s head of climate analysis, David Jones. January 4, 2008
The only uncertainty now was whether the changing pattern was “85 per cent, 95 per cent or 100 per cent the result of the enhanced greenhouse effect”
Note the precision in the probabilities. Very impressive. However, Dr Jones unfortunately appears to suffer from xenophobia. Here’s a communication from Prof Phil Jones (for it is he) gleefully relating in a Climategate email about our Dr David Jones –
2. Had an email from David Jones of BMRC, Melbourne. He said
they are ignoring anybody who has dealings with CA, as there are
threads on it about Australian sites
So Global Warming causes droughts up until a week ago. No doubt they are working on a paper that proves that Global Warming can cause a flood now and then. A peer reviewed article in Nature will appear soon. Data freely available on request except of course to “anyone who has dealings with CA”. That’s the way science is done after all.
Seriously, these two have failed. Failed completely, utterly and abysmally with their climate predictions. After these terrible events abate, these people should be put in front of some sort of panel and held to account for their predictions and asked why they were so wrong. It won’t happen of course but why should anyone give two squirts of guinea pigs piss about their predictions for the future?
Am I pissed off about this? Yes, I am.
But at least a Nobel laureate is on top of it all –
Speaking to an audience of government officials, business leaders and NGOs in Jakarta, the Nobel laureate cited devastating floods in Australia and Pakistan and last year’s drought in Russia as evidence that unchecked global warming threatened famine, poverty and wide-scale destruction
Reader Comments (52)
Australia's BoM believe that in a warming world Australia will both become drier and wetter.
Unfortunate events in Brisbane, etc...
I fear this will be chocked up to "extreme weather" by the ultra-greens and we'll all get an "I told you so..."
Can Josh come up with an official CA badge for those who do want to be proudly associated with CA?
The only question to ask about weather is what weather denotes no global warming? If you cannot state the weather that denotes no global warming you cannot know the weather that does.
I think the idea is that you make it up as you go along.
PS sent this link to Marc Morano. I think it's the kind of thing they like to quote and repost at Climate Depot.
As pointed out recently, because you can't disprove Climate Change, that proves that it must be right :p.
Here is a link to a Google page showing "Queenslander Style Homes". Sorry, but I have lost my note on how to shorten links.
(Actually the url is hideously long. Just set your browser to hunt for Queenslander Style Homes. Worth a few seconds of your time.)
Done that? Good. Did you observe something? Very good. Yes, they are mostly built on stilts.
Reason? That's right, every thirty years or so the area gets serious floods. Call it a climate cycle.
Now, for top marks, what do you call someone who builds at ground level on a flood plain?
And for a bonus, what do you call the self-promoting fool who tells people it's OK, because the area is set for permanent drought, and denies the existence of climate cycles; and how high do you think he should be hung?
Maybe one of our southern hemisphere colleagues could shed some light on a question that has been bothering me about the current situation in Queensland.
It is in relation to the water restriction policy that has been in operation. Now we all know that we should not be wastefull of water but was there any indication of the rate of rise of water in the dams over the past week or so that could have pre-empted an increase in discharge from the dams in order to try to better control the volume of water moving through the area?
Is there a maximum safe discharge rate and how soon after the flood was predicted was this rate achieved in order to protect the citizens and property in the effected area's?
The only reason I ask these questions is that from the interviews on the news that I have seen with Julia Gillard she seems to have spent as much time underlining the water restriction policy as she has in concern over the loss of life and property, which basically astounded me.
Maybe I have the wrong end of the stick on this or perhaps it's too early to ask these questions yet but maybe those of you who are not affected could clear this up for me.
The key point here is not really meteorological, climatological, or 'dam'ological. The key point is the apparent major political influence of unbalanced, possibly unhinged, scientists such as Flannery surfing on the waves of alarm generated in large part by the PR skills of the IPCC. How come the Australian government, and whoever else makes decisions about desalination plants (another part of the Queensland saga) and dams, were so vulnerable to scaremongering? My image (or stereotype if you like) of Australians has them as far more robust characters.
(for some of the extensive 'previous' on Flannery, see http://blogs.news.com.au/heraldsun/andrewbolt/index.php/heraldsun/comments/sky_is_not_the_limit_for_flannerys_scares/)
There must be something in aboriginal folk law about the frequency of these flood events.
http://www.science.org.au/nova/newscientist/105ns_001.htm
Tim Flannery, New Scientist, 2007, Over the past 50 years southern Australia has lost about 20 per cent of its rainfall, and one cause is almost certainly global warming. Similar losses have been experienced in eastern Australia, and although the science is less certain it is probable that global warming is behind these losses too. But by far the most dangerous trend is the decline in the flow of Australian rivers: it has fallen by around 70 per cent in recent decades, so dams no longer fill even when it does rain. Growing evidence suggests that hotter soils, caused directly by global warming, have increased evaporation and transpiration and that the change is permanent. I believe the first thing Australians need to do is to stop worrying about "the drought" - which is transient - and start talking about the new climate.
While the populated east and south of Australia have parched, rainfall has increased in the north-west. This has prompted some politicians to call for development of the north, including massive schemes for dams and pipelines. Some have even called for a large-scale shift of population to follow the rain. Yet computer models indicate that the increased rainfall is most likely caused by the Asian haze, which has pushed the monsoon south. This means that as Asia cleans up its air, Australia is likely to lose its northern rainfall. Australians need to leave behind their dreams of opening a new frontier and focus on making the best of the water remaining to them where they live today.
http://www.wastewaterpractitioners.com.au/purified-recycled-water-no-vote.html
2007 Quotes, Premier Peter Beattie and Deputy Premier Anna Bligh said deterioration in the south-east’s water outlook and compelling advice from the Queensland Water Commission had convinced them to cancel the March 17 plebiscite.
Mr Beattie apologised to the people of South-East Queensland for breaking an undertaking he gave them in what were less serious circumstances.
“I understand that some people have strong views on this issue and I wanted to give people a vote when our planning and forecasting indicated that purified recycled water was an option,” Mr Beattie said.
“The data the Deputy Premier has presented to me upon my return indicates that it appears inevitable that we will have to rely on purified recycled water – it is no longer an option, we have no choice.
“Our water situation has worsened which has required me to reconsider what is in the best interests of our region and its residents.
......... Mr Beattie said the effects of climate change on our region meant we could no longer rely on past rainfall patterns to help us plan for the future.
It looks like the Queensland authorities in 2007 were convinced by climate scientists that climate change meant that floods of the past would not happen in the future.
The climate scientists were wrong, the Queensland government was unprepared, Queenslanders were in effect left defenceless for what ultimately transpired 4 years hence.
John Shade
The 'average' Australian IS of robust,sensible sensible character. Unfortunately, over the past 25 years or so public life and most politicians have been infected by P.C. and environmentalism and, as with sport, they tend to do things well. There is quite a divide between the urban chattering classes,who rival anything Notting Hill can produce, and the average Aussie.
I lived in Townsville for 4 yrs. and Sydney for 9 yrs and I have dual nationality.
Jeff Wood said:
Being an extra couple of metres off the ground also keeps the houses a little cooler don't they?
If so you can hedge your bets on water management issues and temperature issues through houses built on stilts to deal with excessive heat and floods, and dams, dredging and storm drains to retain water when it is in short supply and restrain water when it is plentiful.
Something similar has occurred in the UK - housing estates being built on flood plains and then as an afterthought having the air bricks given a waterproof sliding cover and barriers for the external doors. This then feeds into the climate alarmism argument as more and more homes get inundated by floodwaters which themselves are getting more extreme due to less dredging and upstream flood barriers pushing water to where the defences are weakest or non-existent.
Front page of the National Parks and wildlife South Australia
http://www.environment.sa.gov.au/parks/sanpr/coongielakes/history.html
"The Coongie Lakes and associated wetlands were crucial to the maintenance of the Aboriginal populations due to the availability of resources and semi-permanent water, particularly following flood events."
Clearly flood events are normal in the natural cycle, woven into the language and history. Seems the Climatologists "went out for a duck".
from Reuters, Jan 12th 2011.
http://www.reuters.com/article/idUSTRE70B1XF20110112
Quotes:
"I think people will end up concluding that at least some of the intensity of the monsoon in Queensland can be attributed to climate change," said Matthew England of the Climate Change Research Center at the University of New South Wales in Sydney.
"We've always had El Ninos and we've had natural variability but the background which is now operating is different," said David Jones, head of climate monitoring and prediction at the Australia Bureau of Meteorology in Melbourne. "The first thing we can say with La Nina and El Nino is it is now happening in a hotter world," he told Reuters, adding that meant more evaporation from land and oceans, more moisture in the atmosphere and stronger weather patterns.
You had scientists like Tim Flannery in 2007 arguing that a warmer world would mean a drier Australia and that Australians had to prepare for that.
Now you have scientists in 2011 arguing that a warmer world means a wetter Australia and it is clear that no one in Australia, be it the federal/state government and or agencies had been planning for that eventuality.
Australians have been left badly unprepared to deal with floods and flooding.
I think the issue that isn't really being picked up is the role of the AGW alarmism in bending public policy priorities and budgets.
The (financial strapped) Queensland government spent more than $1 billion building a desalination plant because they were told that drought was now the permanent climate state (as per some of the quotes in this blog above).
Can anyone defend the allocation of public, taxpayer resources in that way when "climate change" was never and still isn't the threat. Simply, unadorned "climate" is and always was the threat and for Queensland that means "floods" (in the southern states it might mean bush fires). The government deserves to be thrown from office for the waste of that $1 billion when we can now see where it might have been more usefully deployed - in flood research, planning advice and emergency response capabilities.
The Climate Change movement is accountable for helping to distort public policy decision making in such a corrupted way.
John Shade:
"surfing on the waves of alarm"
I love the imagery! Thanks.
I like to console myself with the thought that such surfers will find themselves stranded far inland after the storm abates.
The different faces of the BBC were prevalent tonight as depicted by the PM show with Eddie Mayer interviewing a climate scientist he found based in Toowoomba explaining how climate change could be resposible for the floods. Followed by the news at 6 where it was explained about the forces of a particularily strong La Nina producing multiple storm fronts that meteorologists predicted would cause problems.
A quick googling yields this historical snippet wrt the severity and freqency of floods:
http://www.slsa.sa.gov.au/murray/content/dwindlingRiver/floodsDroughtsIntro.htm
In honour of my Australian friends who are have a biblically hard time at the moment, but finding grim humour amid their hardships, I hope they keep safe, and I offer this.
The new parable of Noah
And it came to pass that Noah went far to the south-east, to the land of the queen,
which was called Queensland.
He saw many houses on stilts, for that was the custom of the natives of that land,
which had witnessed many floods in ancient times, and didn’t want another.
No sir, not one bit.
But the people of that land called upon their leaders
– give us more roads and houses, give us more water for crops,
and a decent cricket pitch.
So the government of that land build a mighty dam, by the name of Wivenhoe,
to hold the precious waters for irrigation and crops, and the people rejoiced.
“You beaut!” they cried.
http://www.wivenhoe.gov.uk/images_various/WivenhoeDam/WivDam1.JPG
Now Noah was a wise man too. He said to the people “Let us use this precious water,
and make a garden of this wilderness” – and he did, and he made it known to the world
http://www.noahaustralia.com.au
and he cried “God, this is great”.
—– ~ —–
But there was a group of restless prophets from the land of US-Gore,
who were hungry for fame and fortune. They said to each other -
“These people are heathens, they do not pay us homage, or grants of gold,
Let us lay a report on them which will turn their trousers to brown”.
So they scribed for years, making public many dire predictions,
and they called it UN-IPCC, which put fear in the hearts of many innocents,
who were without learning in the ways of Basic Science, Pressure Groups and Stealth Taxes.
They put their predictions on many pages, and published on the Interweb thingy,
For Queensland, it proclaimed – there will be dryness and droughts!
Which was a bummer for the farmers.
(The leaders of the land of Queensland were not sad, for they were hungry too,
for reasons to create new tythes and taxes upon the people of the region,
to pay for their holidays and conferences with riches and first-class travel)
But copies of the prediction had travelled afar, to places like GWPF in The Old Country,
http://www.thegwpf.org/ipcc-news/2160-ipcc-prediction-for-queensland-less-rainfall-longer-droughts-drier-climate.html
who noted its contents, and patiently bided their time, for they were wise men too,
they were learned in the ways of Basic Science and Pressure Groups,
and they could smell a rat as well.
—– ~ —–
Now the cry of Noah had taken a while to reach the ears of God, because she’d been away.
She looked upon the Earth, and was amazed, and she wondered to herself.
“WTF have they been doing?”
So she caused the Sun to slow on its axis, and its fires diminished,
and its warming rays decreased, and the Earth grew cooler.
Snow fell open the innocents and the UN-Gore false prophets alike,
even unto their conference in Copenhagen. Which was biblical, and poetic,
and righteous, because lots of fairy stories had come from there,
in the name of Hans Christian Anderson in times before.
And as the Earth grew cooler, so did the waters of the great oceans,
the Pacific and the Atlantic, and water and snow rose up to the heavens,
and then it all came down again. But not where the false prophets had promised.
The leaders of the land of Queensland were bemused and confused.
Had not they been promised drought? So they delayed and dithered,
and all the time they were delaying and dithering, the waters in
the dam of Wivenhoe were rising higher and higher.
“Let out the water, you drogos!” some people cried.
But their voices were not heard above the clamour of the warmists,
and still the rains came, and the people said
“Strewth, it’s getting mighty wet round here”.
Now the wise men of GWPF called out, and they said “Told you so!”
And Noah was called into action, to do something, for God’s sake.
So he called upon the creatures of the land.
“Two koalas, two dingos, two kookaburras, two wallabies, two goannas –
stop, none of them blurry cane toads – two crocodiles…..”
—– ~ —–
I’m sure I should add something about how the Ashes were lost,
which had been a premonition of terrible disaster still to come.
But was it a prediction, or a forecast as well?
For those interested in the history of Queensland floods see the Australian BOM http://www.bom.gov.au/hydro/flood/qld/fld_history/index.shtml, unfortunately not update beyond Nov 2010 but the current floods have not reached the severity of flooding in the 1970s according to reports.
What is mind boggling about these floods is that in most, if not all, of the towns affected by the floodwaters, there are markers recording the height of previous floods going back 100 or more years on lamp-posts. Often these markers are several metres above the ground.
The question then is why are people allowed to build houses and businesses below these known flood levels? Unbelievable. Yet it happens all the time.
As an Australian taxpayer, while I of course am devastated by the loss of life and assets in the floods, the reality is that due to STUPID decisions by councils, planners, builders, bankers, and houseowners to build below known flood levels, we taxpayers are expected to pay for it all.
These people, as well as the climate alarmists who told them that there would never again be major rainfall events, should be held to account.
These are avoidable events. The old-timers knew where the flood levels were, and almost invariably avoided building anything valuable where it could be destroyed by the inevitable floods.
re the Queensland floods;-
How can a reservoir be 190% full? It's either full up to the spillweir level, 100% full, and overflowing or it's not. Are the reservoirs referred to perhaps multi-purpose serving as both water supply and flood storage? But then the normal situation would be for the flood storage to be above the supply storage but again limited by the spillweir level. 190% full just doesn't make sense to me.
emckeng
Maybe it's like red-lining your car. You can you can red-line it for a short period of time, but not recommended or optimal. Something is bound to break. Maybe 190% means it can hold water, but not optimal...something is gonna break. Maybe an engineer can comment about stress tests.
Professor David Karoly - Australia's Jim Hansen:
''Australia has been known for more than 100 years as a land of droughts and flooding rains, but what climate change means is Australia becomes a land of more droughts and worse flooding rains,'' David Karoly, from Melbourne University's school of earth sciences, said.
Professor Karoly stressed individual events could not be attributed to climate change. But the wild extremes being experienced by the continent were in keeping with scientists' forecasts of more flooding associated with increased heavy rain and more droughts as a result of high temperatures and more evaporation.
''On some measures it's the strongest La Nina in recorded history … [but] we also have record-high ocean temperatures in northern Australia which means more moisture evaporating into the air,'' he said. ''And that means lots of heavy rain.''
Sydney Morning Herald - 12 January 2010
Every extreme natural event will in future be caused by....YOU.
David Jones and Kevin Trenberth both comment on the Queensland floods in the context of climate change, and I have posted on it here:
Queensland floods: Bureau of Meteorology blames climate change.
Best wishes,
Simon
ACM
For readers unfamiliar with SE Queensland, Wivenhoe is a multiple use dam. It serves as flood control, drinking water supply, recreation and hydro-electric generation. (It has 2x250MW pumped storage pumps/generators, which were valuable for peaking power in a predominantly thermal system, though less so now that there is a national grid and Queensland is connected to the Snowy - and Tasmania).
I would suspect that its releases have helped smooth the flood peak, with more releases early and then withholding water that would have added to the peak. The critical questions will be whether it was run down sufficiently in advance of the monsoon, so that it could hold back as much water as possible. (The SOI was at a record figure in December, so it should have been a predictable risk).
At a more strategic level, the questions about building on floodplains (especially concrete slabs rather than 'Queenslanders' on stilts) will be those that should be put to state and local governments. (I lived in both in my seven years there). The possibility of additional dams is not without relevance. I seem to recall Wivenhoe was to have been accompanied by other measures and dams. Dams are not a panacea, especially as mutiple-use facilities require trade-offs to be made, but they are valuable.
At least these floods are roughly a metre below the 1974 flood levels. That should tone down the global warming rhetoric! (Fat chance I think!!)
As an amusing aside, the authorities ran the numbers through a computer model that predicted a flood peak much higher than the 1974 level. The peak didn't come close. Seems even the flood models are written by climatologists!
As an unamusing aside, there are a lot of displaced people in Queensland who have lost everything, including family members. Each of the major Australian newspaper sites have links to charity organisations that are helping these people. I'm sure any donations would be gratefully accepted.
The precautionary principle apparently does not apply here?
As a card-carrying AGW sceptic (as many hydrologists are) I hesitate to provide support to those climate scientists that predicted a higher frequency of droughts in Australia. However, here is nothing inconsistent in having areas with significant droughts and occasional floods. North coastal Peru is an example which is normally very dry but devastating floods often occur during an El Nino.
The problem is that the climate scientists "sold" a simple message regarding a higher frequency of droughts in Australia. If they had been more honest about the complexities and uncertainties in understanding future climate they would likely have more credibility today.
Having said that, there is obviously no reason to suppose that the Queensland floods have anything to do with AGW even if they had been the largest on record. River flow records throughout the world are comparatively short so exceeding the largest flow on record should occur quite often even under a stationary climate.
At least we can see the funny side of our desalination plant
we , in the UK, have Professor Dr David Parker, from the Hadley centre, to be "proud" of.
Have BA and BAA allready sued him for a few 100million?
they were completely entitled to not investing in snow plows with a nutter making no-snow predictions out of thin air, allready in 2001.
Wivenhoe Dam was built for water storage and flood protection. 100% is the level where the water storage component is considered full. The dam can still take more water for flood protection but at 190% it has no choice but to spill and this has contributed to the current flood.
"multiple storm fronts that meteorologists predicted would cause problems."
As a pertinent aside, how many climatologists have any meteorological experience/training?
Vaulting loftily
Over the wretched waters
Trenberth jumps the shark.
===============
My the trolls have gone quite! I guess they have had to go back to HQ to figure out how to spin this one!
My thoughts are with all down under who have lost loved ones and their homes.
This on Andrew Bolt's blog..."Karoly’s “global warming” - wetter, drier, worse, better, whatever" with the comment by Professor Stewart Franks about David Karoly...
"You are arguably the best example of the corruption of the IPCC process, and the bullshit that academia has sunk to. Shame on you."
Franks work has shown a link between increased likelihood of extreme weather events during La Nina/Cool PDO cycles. It seems this work has been ignored by Government.
Many questions asked by various people on this thread. I'll try to answer as many as I can.
I work in the Infrastructure Services office of a Council just to the north of Brisbane. One of my jobs is to undertake flood studies and storm water design within my council reagion. I started as a trainee 25 years ago, my main job then was to handle storm water enquirees. (ie: I'm qualified to make statements on the subject).
Flood areas are well known, and I've been to conferences where the Brisbane Council were showing off their very detailed flood models. They have books on the front counter of Council which can be viewed by anyone that show every suberb and detailed flood models for (I think) a 50 year event and 100 year event.
Anybody who buys a house will get detailed information regarding any historical flooding in the area, and estimated flood heights for the 100 year event. The information is compulsory so you can't not get it. Most locations have minimum floor levels set, these levels are the 100 year flood event plus 300mm.
There are many towns such as Gympie, Brisbane, Mackey which get flood in the town regularly. In most cases you can't get flood insurance on a property where floods have happened in the past. We have flood height records going back to the 80's, with a library of photoes of flood events going back to the 40's.
In most of the cases where damage has occured, it was water velocity which caused the damage, not the fact that it was inundated. Towns in central queensland are almost always built on flood planes are go under water every 10 years or so. Its a known risk by those who live there, which is why you'll find TV crews interviewing people sitting on a varanda or in a pub drinking with water around their ankles. Its neither uncommon nor a surprise.
For those who want to know more, you can look up the Brisbane City Council web page and search for flood information. I"m sure it will be extensive. For flood modeling, we generaly use a 10 year storm event for street design, a 100 year storm event for town CBD, high ways, and overland flows through estates so that no water in a 100 year event should cause property damage in new estates (that is the design criteria, in practice it doesn't always work out that way). Dams and major bridges are designed for 100 year events, 1000 year events and what is called a Maximum Possible Flood event (I don't know much about this one though).
Now just for fun, I'll see how this mess will turn out. This is an extract of the IFD chart for Noosa Heads.
The storm event far left in minutes, the return interval along the top, and the grid value is the rainfall intensity per hour. I've cut it off at 720 minutes (12 hour storm event) but we have much longer.
Noosa Heads
min 1 2 5 10 20 50 100
10 100.58 127.65 157.21 174.02 197.36 227.78 250.90
20 73.73 93.72 115.89 128.56 146.05 168.91 186.31
30 60.18 76.58 94.94 105.46 119.96 138.92 153.36
60 41.34 52.70 65.65 73.11 83.34 96.75 106.99
120 25.96 33.44 42.81 48.38 55.82 65.71 73.34
180 19.65 25.47 33.14 37.78 43.91 52.12 58.51
270 15.91 20.71 27.25 31.24 36.49 43.56 49.09
360 12.17 15.95 21.35 24.70 29.07 35.00 39.67
540 9.87 12.99 17.57 20.45 24.19 29.29 33.32
720 7.57 10.02 13.79 16.20 19.30 23.57 26.97
Greg Cavanagh --
Thanks for that information, it helps put this flooding in context for those of us who don't live in flood-prone areas.
Just checking -- the units for your table are mm/hour?
MarcH - here is another link to that email together with the one Prof Franks wrote to the ABC. He suggested that they look a little wider than Karoly (an alarmist of heroic proportions) when asking for a scientific assessments of the floods. Well worth a read. Here's A/Prof Franks to Prof Karoly -
Not a lot of consensus talk there I'm afraid.
@Lord Beaverbrook
"It is in relation to the water restriction policy that has been in operation. Now we all know that we should not be wastefull of water but was there any indication of the rate of rise of water in the dams over the past week or so that could have pre-empted an increase in discharge from the dams in order to try to better control the volume of water moving through the area?"
Wivenhoe Dam has been close to 100% full since April last year. This graph still shows it at 100% level though the real figure is much higher. It seems the authorities were balancing the water needs with the rain forecasts.
Part of the reason for flooding in Brisbane City areas is because Wivenhoe Dam had to be allowed to discharge more water to cushion the rising levels and to prevent a dangerous spill-over. Reportedly, there is an emergency spillway from the reservoir as well should the levels get even higher.
Flood levels in Brisbane did not reach 1974 levels but this need to be considered in context. Had it not been for Wivenhoe dam the levels would be much, much higher than 1974, when only half the number of people lived in Brisbane.
HaroldW
"Just checking -- the units for your table are mm/hour?", yes they are, my bad.
So a 20 minute 50 year storm event has a rainfall rate of 168.91 mm/h. But it only lasted 20 minutes, so you actualy get 56mm of rain in 20 minutes.
When modeling a rainfall event you also have to apply a rainfall hyetograph which subdivides the rainfall intensity into higher and lower intensity times within the rainfall event. A manual called Australian Rainfall & Runoff 2001 is the storm design standard for all of Australia.
Hey Mac
Please send young Tim F round to see me.
I have some charts he may want to see.
Like rainfall for Sydney for example, which has been flat since 1856.
(long term trend y = 0.0998x - 11.345, R² = 0.0002).
I have a number of similar charts for widely dispursed sites in Australia.
I got raw data from BOM. I wonder where his data came from?
Perhaps it was "value added. I can't compete with "value added" data.
Greg Cavanagh --
Thanks. Plus I learned a new word today; I had never heard of a hyetograph. And now I know the difference between a hyetograph and a hydrograph. It's always interesting to get a peek -- even a small one -- at the engineering which supports the "bottom line" predictions which are usually the only elements which one sees.
Computer models were used to foretell river heights in Brisbane. All were impossibly overstated and totally incorrect in forecasting the next days flood peak (and the next 2 days). We are to trust computer models for the next 100 yrs of "climate change?" Geez....
SHx
Thanks for the info and links, it's good to see the responce was appropriate to the situation. Would there have been any benefit from having the levels at 60% to begin with rather than 100% or is this figure immaterial as it refers to less than 50% of overall capacity?
Hi Lord,
Wivenhoe is a multi-purpose dam. It is used for power generation and for clean water as well as flood prevention. I am not certain about this but I suspect when they talk about '100% capacity', they mean it for power and fresh water purposes. The remaining reservoir capacity, 'up to 225%' that is, is for flood prevention.
Should water in the reservoir have been reduced to 50% or 0% capacity considering the forecasts for precipitation? Well, hindsight is always a good thing. And this question is definitely going to come up for the Royal Commission that often follow these kinds of disasters in Australia.
So far in Australia there has been no political recrimination on this specific issue. If anything, the previously unpopular Bligh Labor government has come out very well from this disaster. A Sydney Morning Herald internet poll has found that 95 percent of the participants think the Premier of Queensland, Anna Bligh, has done an 'outstanding' or 'good' job. This is unprecedented.
SHx
I hope there is a let up in the rain for you all. We have family in Rockhampton who thankfully were not flooded out but are pitching in for those that were. The supplies are low, there's only weight watchers food left in the stores, but their biggest concern is " the bladdy XXX factory is under water, that's gotta be No1 priority".
They've only been there 5 years but I think the conversion is complete!
Should have been XXXX factory. My bad.
LB,
glad to hear your family is OK.
I live in Sydney's inner west. Over here, the Mexican beer is the most popular. It is called VB. I have never seen XXXX served on tap here or in Melbourne.
But, Melbourne, Sydney or Brisbane, we all like XXX. :-D