Thread: Floods - Stupid things journos say

Originally Posted by hook

From the Lord Mayor Brisvagas
He states in his early news confrance 1000hr 11 Jan, tells everyone "the Wivenhoe dam will do its job and we won't see another 74 flood".

he changed his tune at about 1800hrs that day, to people to get ready.

All he did is slow people down with his un truths.
This is when the dam is at 140%, where do you think the water is going to go.
I now the dam got to 190%

Umm i am not a fan of him but to give him credit he gas been saying and warning since October that we will have a flood like 74 some time this wet season so I find that statement very hard to believe


Sent from my iPhone

Originally Posted by NomadicD3

LMAO,Ok Vlad time for a little more reporter/news bashing. Now i hear you all complaining about how the eastern states media treats the viewers like idiots, wellll i bet you can't top our lot here in Perth. They actually brought on a highly trained Hydrologist who was asked and i quote "So what's going on in Qld?" To which she replied, and i'm serious " Flooding" But to further elaborate she then went on to explain what flooding actually was ROTFL. So for those who may not know, "flooding is when too much rain falls in a short period of time and the run off can not be handled by the areas river system"
Took us 10 mins to stop laughing at work and gave us great material for the rest of the day.

I think that is fair enough.

I have been led to believe that there has been no worthwhile rain in southern WA in living memory. There must be a lot of young people in WA who have never seen rain, let alone flooding, so it was probably a good idea to explain those phenomena to viewers.

Originally Posted by vnx205

I think that is fair enough.

I have been led to believe that there has been no worthwhile rain in southern WA in living memory.

Actually, the south west corner of WA has about the most consistent rainfall in OZ. They may not get as much as brisbane on average, but it turns up without fail every winter.

However, Perth doesn't even have stormwater drains worth mentioning that shocked me when I first got here. The gutters just run into soakwells (small holes in the ground) - if that! The rain just soaks into the sand - even that day a couple of years back when we got 100mm in 2 hrs - about the same as toowoomba got a couple of days ago.

What about when the council has the study done, then covers it up?
Former Brisbane councillors did just that: article link, to see graphics

Quote
Alarming report on Brisbane River risks covered up

* Hedley Thomas
* From: The Australian
* January 12, 2011 11:00PM

Source: The Australian

A SECRET report by scientific and engineering experts warned of significantly greater risks of vast destruction from Brisbane River flooding - and raised grave concerns with the Queensland government and the city's council a decade ago.

But the recommendations in the report for radical changes in planning strategy, emergency plans and transparency about the true flood levels for Brisbane were rejected and the report was covered up.

The comprehensive 1999 Brisbane River Flood Study made alarming findings about predicted devastation to tens of thousands of flood-prone properties, which were given the green light for residential development since the 1974 flood. The engineers and hydrologists involved in the study warned that the next major flood in Brisbane would be between 1m and 2m higher than anticipated by the Brisbane town plan.

The study highlighted how the council had permitted the development of thousands of properties whose owners were led to believe they would be out of harm's way in a flood on the scale of 1974.

The study was leaked to this reporter in June 2003 by a high-level public servant, who revealed that the local and state government at the time were less concerned with flood risks and more interested in seeing property development in low-lying areas.

"The flood immunity of properties is less than previously assessed. The average flood damages associated with flooding will be significantly higher. There are potential legal implications for council by allowing development to occur in higher-risk areas. As a minimum, developers and residents may need to be advised of the actual flood risk on their property," the study says. "All elements of the study have been subjected to independent peer review because the key findings have significant implications for council.

"The major finding of this study is that the calculated one-in-100-year design flood flow . . . is about 1m to 2m higher than the current development control in the Brisbane River corridor. The simple option of saying that the current development control level represents the one-in-100-year flood level is not valid."

But after receiving the study in 1999 the council adopted a "no change, maintain status quo" strategy -- despite its expert review advising that such a strategy was "poor" because it would reduce flood immunity, increase council's liability and cause the loss of Natural Disaster Relief funds. In the debate that followed its leaking it emerged that misplaced faith by governments and residents in the flood mitigation potential of Wivenhoe Dam played into the hands of property developers, who were profitably turning low-lying swaths of Brisbane into expensive housing.

The Crime and Misconduct Commission investigated the cover-up of the study and recommended better transparency for ratepayers.

The then Labor lord mayor, Tim Quinn, and others in the civic cabinet at the time had known about the study for four years but withheld its existence from ratepayers -- until its leaking forced it into the open. Mr Quinn said then that the study was a "draft" and incomplete and that was why neither he nor his predecessor Jim Soorley had acted on its findings.

Mr Quinn was ousted as lord mayor months after the furore by Campbell Newman who campaigned against secrecy over the flood study and radically overhauled policies to warn the public of the severe risk of another major Brisbane River flood.

Mr Newman, an engineer, said at the time: "A vital study of immense public importance has been kept secret from the community for four years. The council has had this knowledge since 1999 and yet there has been no change in development or building rules reflecting the recommendations in the study. The effect of this is to leave a lot of innocent purchasers of riverfront property exposed who need not have been exposed.

"How can it be 'buyer beware' when the council is not providing the necessary information to purchasers.

"This is totally unacceptable given that people rely on their council for information to assist them when it comes to property matters and particularly safety.

"It's a case which could have a huge impact on people's lives."

Originally Posted by isuzurover

I don't know for sure that the 4 floods in the last ~120 years were all classified as 1 in 100 year floods??? Some may have been 1 in 50 or 1 in 200???

I believe that the term "1 in 100" isn't statistically derived, but more of a term to describe a significant event against the average regardless of when or how often it happens.

I'm not sure mother nature has this sort of thing marked on her calendar...

Originally Posted by pando

I believe that the term "1 in 100" isn't statistically derived, ...

Sorry, but your belief is incorrect...

Originally Posted by wikipedia

A one-hundred-year flood is calculated to be the level of flood water expected to be equaled or exceeded every 100 years on average. The 100-year flood is more accurately referred to as the 1% annual exceedance probability flood, since it is a flood that has a 1% chance of being equaled or exceeded in any single year.[1] Similarly, a flood level expected to be equaled or exceeded every 10 years on average is known as a ten-year flood. Based on the expected flood water level, a predicted area of inundation can be mapped out. This floodplain map figures very importantly in building permits, environmental regulations, and flood insurance.


Probability

A 100-year flood has approximately a 63.4% chance of occurring in any 100-year period, not a 100 percent chance of occurring. The probability Pe that a certain-size flood occurring during any period will exceed the 100-yr flood threshold can be calculated using Pe = 1 – [1-(1/T)]n where T is the return period of a given storm threshold (e.g. 100-yr, 50-yr, 25-yr, and so forth), and n is the number of years. The exceedance probability Pe is also described as the natural, inherent, or hydrologic risk of failure.[2][3]

Ten-year floods have a 10% chance of occurring in any given year (Pe =0.10); 500-year have a 0.2% chance of occurring in any given year (Pe =0.002); etc. The percent chance of an X-year flood occurring in a single year can be calculated by dividing 100 by X.

The field of extreme value theory was created to model rare events such as 100-year floods for the purposes of civil engineering. This theory is most commonly applied to the maximum or minimum observed stream flows of a given river. In desert areas where there are only ephemeral washes, this method is applied to the maximum observed rainfall over a given period of time (24-hours, 6-hours, or 3-hours). The extreme value analysis only considers the most extreme event observed in a given year. So, between the large spring runoff and a heavy summer rain storm, whichever resulted in more runoff would be considered the extreme event, while the smaller event would be ignored in the analysis (even though both may have been capable of causing terrible flooding in their own right).

Originally Posted by isuzurover

Sorry, but your belief is incorrect...

wow, I'll shut up then.......

Originally Posted by isuzurover

Sorry, but your belief is incorrect...

you mean "according to wikipedia your belief is incorrect"