Guest essay by Eric Worrall
According to UNSW academic Dr. Clara Stephens, future extreme rainfall will fail to fill Aussie dams, because the drier ground will absorb too much moisture.
What you might not realise about the flow-on effects of climate change
Fri 14 Aug 2020 10.42 AEST
In the coming years, we are likely to see more extreme weather conditions. We will need new engineering approaches to manage the complex impacts on our water resources, writes Dr Clare Stephens.
…
Changing rainfall, evaporation and soil
Climate modelling suggests that, in the coming years, average rainfall will decrease over much of the continent. Simultaneously, extreme rainfall is likely to increase, bringing heavier downpours.
Much of the rainfall over Australia is lost to evaporation. The “thirst” of the atmosphere is measured by its evaporative demand. Since the Millennium Droughtbegan in the 1990s, higher temperatures have driven evaporative demand up by increasing the air’s capacity to hold water vapour.
Decreasing annual rainfall and increasing evaporative demand will tend to result in drier soil. Drier soils are more absorbent, so less rain runs directly into waterways. This means that, even if we get heavier downpours in the future, they won’t necessarily produce the floods we rely on to fill dams. Unfortunately, this flood-reducing tendency won’t apply equally to urban environments (where it might actually be helpful) because we have paved over that absorbent soil in cities.
…
Read more: https://www.theguardian.com/westpac-scholars-rethink-tomorrow/2020/aug/14/what-you-might-not-realise-about-the-flow-on-effects-of-climate-change
This echoes Tim Flannery’s famous prediction that Aussie dams would never fill again – shorty before record flood years.
Predicting the end of rain is an old game. In the 1920s American hit music hall song “It aint going to rain no mo'”, full of rude verses which poke fun at alarmism, was a worldwide success – not a bad effort in the age before mass media.
“Climate modelling suggests that in coming years” many will ridicule the fools who believed in their simplistic and wildly inaccurate climate models.
A poet had the extreme Aussie weather nailed in this poem from 1919
“We’ll all be ‘rooned’ ” said Hanrahan,
In accents most forlorn,
Outside the church ere Mass began
One frosty Sunday morn.
The congregation stood about,
Coat-collars to its ears ;
And talked of stock and crops and
drought
As it had done for years.
“I believe y’re right,” said Daniel
Croke ;
“You’ll find I’m right, bedad,
For never since the banks went broke
Has seasons been so bad.
” It’s looking crook,” said young O’Neil ;
At which sedate remark
He squatted quietly on his heel,
And chewed a piece of bark.
And all around the chorus ran —
“It’s keepin’ dry, no doubt.”
We’ll all be ‘rooned,’ said Hanrahan,
“Before the year is out.”
“The crops are done; ye’ll have your
work
To get one bag of grain;
From here ‘way out to Back-o’-Bourke
They’re singing out for rain.
“They’re singing out for rain,” he said,
“And all the tanks are dry ;”
The congregation scratched its head
And looked around the sky.
“There won’t be grass, in any case,
Enough to feed an ass.
There’s not a blade on Casey’s place
As I kem down to Mass.”
” If rain don’t come this month,” said
Dan
And cleared his throat to speak;
“We’ll all be ‘rooned,” said Hanrahan,
” If rain don’t come this week.”
A heavy ssilence seemed to steal
On all at this remark;
And each man squatted on his heel, and
chewed a piece of bark.
“We want an inch of rain, we do,”
O’Neil observed at last ;
But Croke maintained we wanted two
To put the danger past.
“If we don’t get three inches man,
Or four to break this drought,
” We’ll all be ‘rooned'” said Hanrahan.
“Before the year is out.”
In God’s good time down came the rain,
And all the afternoon
On iron roof and window pane
It drummed a homely tune.
And all the night it pattered still,
And lightsome sleepless elves
In dripping spout and windowsill
Kept talking to themselves.
It pelted, pelted all day long
A singing at its work,
And every heart took up the song
‘Way out the Back-o-Bourke.
And every creek a banker ran,
And dams filled overtop.
“We’ll all be ‘rooned'” said Hanrahan,
‘If this rain doesn’t stop.”
But stop it did in God’s good time,
And spring came in to fold
A mantle o’er the hills sublime
Of green and pink and gold.
And day went by on dancing feet,
To harvest hopes immense,
And laughing eyes beheld the wheat
Nid-nodding o’er the fence.
And oh; the smile on every face,
As happy youth and lass,
Through grass knee-deep on Casey’s
place
Went riding down to Mass.
But round the church in clothes genteel
Discoursed the men of mark ;
And each man squatted on his heel
And chewed a piece of bark.
“There’ll be bush fires for sure, my man.
There will beyond a doubt.
“We’ll all be ‘rooned’ ” said Hanrahan,
“Before the year is out.”
+97
Seems like the poets know more about Australian climate than the PhD’s.
The skies are brass and the plains are bare,
Death and ruin are everywhere –
And all that is left of the last year’s flood
Is a sickly stream on the grey-black mud;
The salt-springs bubble and the quagmires quiver,
And – this is the dirge of the Darling River
– The Song of the Darling River by Henry Lawson (1891)
Luv it👍
Hammer. Nail. Head.
That poem’s the duck’s guts TonyB, thanks for sharing.
no waiting years
this is tonights Bom report for NSW
https://www.eldersweather.com.au/news/warragamba-dam-at-capacity/532329
“According to UNSW academic Dr. Clara Stephens, future extreme rainfall will fail to fill Aussie dams, because the drier ground will absorb too much moisture.”
Ironically, she has it backwards. When the ground is bone dry, it can’t absorb the rain as quick as when it is already partly wet and/or partially saturated and be able to still hold more water. So the reservoir will fill faster initially, because it will all be run off instead of the soils absorbing the water.
Yep, not a good start to her career.
She drinks too much beer.
And obviously has never watched how it runs off after she’s done with it.
Rude, but good!
And it has actually made her more attractive (hats on for misogynistic comebacks 😱)
Yes, another Pretty Polly squawking out immitations of something someone has repeatedly told her!
I don’t know how this idiot got a PhD. They must be the prize in a box of cracker jacks. Her understanding of the topic is abysmal.
John
She got her PHD by singing the right tunes for her supper.
Way to go down in flames ..
https://www.waternsw.com.au/supply/Greater-Sydney/greater-sydneys-dam-levels
As At Monday 17 August = 100 %
Same for Tasmania and 75% for Canberra.
Perth is the lowest at 43% which is nothing unusual it was the same for last 3 years and the desalination plants will be running hard again this year providing 48% of our water.
Almost every state built desal plants when the scare was first raised. Yours is the only one that’s actually gotten value out of it – apart from a few green votes.
Also the long term rainfall is increasing.
http://www.bom.gov.au/climate/change/index.shtml#tabs=Tracker&tracker=timeseries&tQ=graph%3Drain%26area%3Daus%26season%3D0112%26ave_yr%3DT
from UNSW:
“Clare is a post-doctoral researcher and chartered engineer with the UNSW Water Research Centre. Her key interests are in hydrology and climate change, with a focus on ecohydrologic modelling and data analysis. She obtained her PhD from UNSW, researching the performance robustness of hydrologic models under climate change. Clare was selected as a Westpac Future Leaders scholar in 2016 and the Young Environmental Engineer of the Year (Engineers Australia) in 2015. Before starting her research career, Clare was a consulting engineer working on flood risk management and infrastructure design projects.”
So more evidence that contemporary PhD are awarded by ticking all the (politically) correct bullshit boxes it would appear.
I certainly never heard of such nonsense as ‘ecohydrologic modelling’ or peering into crystal balls to guess how hydrologic models would perform in the future under the influence of could/might/maybe imagined weather. But then again, I studied hydrology long before gullible warming became the bed wetter’s cause du jour, and according to a thesis I recently participated in (as a interviewee), it would appear I am suffering ‘cognitive dissonance’; which I assume is the preferred modern term describing a person who retains critical thinking skills and formulates opinions individually rather than agreeing with the prevailing group think.
Ironic yes, but so predictable. How would one who so confuses computer output with reality ever get real life hands on dirt under the fingernails experience? The poor girl may be highly educated but is as dumb as a sack of hammers at what really matters.
That ain’t dum; thass iggerant.
She’s not “highly educated” she’s “highly attended” (as in “I attended grad school…”).
Not sure how she could get this so wrong unless the article is over-simplifying her reasons.
It is amusing to see a reliance on a bad thing like “flooding,” particularly in cities, to fill reservoirs.
Clara wrote:
It seems pretty clear what she was trying to say.
Seems like she should know better from her quals…just wondering if she had to oversimplify and “drier” means “still wetted but drier than in the past.”
Still poor wording and still looks like a heap of garbage.
I thought of that, but her suggestion about rain not filling dams because the dry soil soaks up too much moisture is just stupid.
I guess it’s possible some know all guardian hack edited her original explanation.
She needs to look out the window. We in eastern OZ have come out of a very severe drought when the soil became so dry that Eucalypts were dying. Then the rain came and yes the soil soaked it up and most of the trees have recovered. The dams in the east coast Hunter Valley are now average 80% full with several 100%.
It is just make believe.
Any discussion about more this or less that relating to floods and droughts need to be catchment specific.
Catchments have different shapes , slopes, sizes and levels of development.
The best the climate models do is give a percentage range for more or less rainfall by season.
Every catchment within the region will likely have a different outcome.
Any person who experiences a drought knows this. It’s a major problem in the Midwest (and elsewhere), if the ground is on one extreme or the other (too wet or bone dry), you can bet money on floods, over-burdened reservoirs, destroyed crops, washed away roads, etc.
Not sure why someone like “Dr” Stephens would dismiss what is both logical and empirical.
When i moved to France just over 20 years ago, I wondered why the farmers disc harrowed lines on the recently harvested fields, something that I had not seen in the UK.
The answer; to allow the rain to penetrate the ground. If they did not harrow the fields the rain would run to the lowest part of the field.
I do the same every year. Plough in late October rotavate in mid spring and sow immediately. I live in central west france. I listen to my neighbours.
Interestingly, my neighbours are all old, like me, and their families have lived on the same land for well over a hundred years. They all say the same thing. AGW is nonsense. Climate is cyclic.
As for the rain running to the lowest part of the field. My property extends to 300metres long and at the furthest point is 130m above sea level where the house is 30metres lower. It rises very quickly. About 25metres over 50 metres. The summer, like this year, is very dry. The rains arrive in October and flood the bottom corner of the front garden. Why ? Because water runs down hil very rapidly over the very dry land. It takes about a week of rain, every day, to dampen the ground sufficiently to hold more water.
on old farmland in france….dont they have “french drains” in place from decades ago?
woulda thunk so;-)
Dry ground can also becomes repellent and therefore allows for better run off. So this will allow all those privately / foreign owned mega dams to fill quicker before they allow their run off to get to the river systems.
Yes . . . it’s a fundamental reason why very dry desert areas are so prone to flash floods when they very rarely receive a heavy rainstorm.
Drier ground, will cause better run off in may cases as the soil is too hard to penetrate. Watch what happens to rain when it falls along the natural water courses that empty into the Lake Eyre basin. It’s NOT rocket science!
This matches with my take
true.
to try n stop non wetting soil issues using soapy water breaks the bonds and allows ingress faster
some farms use such tactics I heard the amway companies used to flog their loc for just that purpose
expensive though
dish detergent works fine, as does laundry water for home gardens
o f course the old fashioned turned tilled soil before rains due also works rather well:-) soils dry bits get ripped round n the broken open areas get water pooling to soak in not run off
She has also got screwed up about evaporation and rainfall.
She says: Quote: “Decreasing annual rainfall and increasing evaporative demand will tend to result in drier soil. “
The Hydro Cycle works as a Rankine Cycle and is essentially a closed system where evaporation EQUALS condensation/rain etc.
Matters of the random distribution of the rain is a separate and chaotic subject open to conjecture.
Note: In the Rankine Cycle any increase in energy input results in an increase in the RATE of the cycle but NOT in the mass of the working fluid. Don’t take my word; have a look at how our steam generating plants work.
This is why global specific humidity flat lines within a smidge or two.
I’ve seen examples of this in Israel’s Negev Desert, where they have to build rings of earth around each planting to retain the occasional rain. Where a road crosses a dry river-course or wadi, there are DEPTH warning signs, and I was told by a colleague of camping in such a river-course during his call-up. One night there was an urgent radio call that there had been a rain shower further up in the hills – and they should GET OUT NOW! A couple of minutes later, a 2-3 metre high wall of water came down the wadi, washing all before it! So, REAL scientists know that water will REALLY run off a dry, compacted soil.
She fixed your real world observation with the assumption that absorption rises as moisture content falls. She learned to do so in her social justice class.
Right on Earthling 2!
Anyone who’s seen a flash flood in the desert knows this. The process is called skinning. In the dry months wind moves the finest particles first, forming a skin of powder-fine dust on the surface which causes the water to ‘bead’ and flow over the the surface without wetting the soil/sand.
cheers
Mike
“Clare Stephens is one of 470 Westpac Scholars who are setting new benchmarks in innovation, research and social change.”
These sixpac scholars are “setting new benchmarks for social change” so consequently they have less time and attention for research, hence lower benchmarks for the core issue of Science.
The ‘social change’ goals inevitably skew the selection and interpretation of data to achieve a preselected outcome. That is incompatible with real science, which follows the facts regardless of pet theories and personal prejudices.
‘new benchmarks’ aka KPI’s and using critical thinking speak ‘innovation, research and social change’ just means regression while pretending its progress, like Michael Jackson’s ‘moonwalking’, all just a form of performance.
And again I embarrassed to be a UNSW engineering graduate although with a good number of decades to separate me from the recent degradation. Rather staggering that a civ. eng. would buy into this sort of crap but I guess the renaming of the faculty from Civil to ‘Civil and Environmental’ really was a disgarding of the reality of traditional engineering and an embrace of the ‘humanities’. Very sad.
The movie inconvenient truth was feed to Australian government authorities in about 2006.
About the same time theses authorities came up with the more droughts and more floods scare in its various forms.
After 14 years there has not been any quantitative assessment to prove this.
Droughts and more intense rainfall are statistic concepts. It is total BS that a catchment has both.
The last time the dams didn’t fill was the 2010 deluge.
Oh wait – that’s when most of SE Queensland went under because the main storage dams were in danger of overflowing, and gigalitres (or thousands of Olympic swimming pools) had to be released as an emergency measure.
I believe a negligence lawsuit has either just been settled or is ongoing against the Qld government?
Perhaps young Dr Clara should study modern history before speculating about the likelihood of dry dams.
Another issue that hit some of those downstream towns was that some local councils when laying drains did not follow an engineers advice to install 10″ drains and installed 6″ drains instead to save money.
And this was after Tomfoolery (er-Tim Flannery) predicted that the dams would never fill again
“It ain’t gonna rain no more” my favourite:
https://youtu.be/a2v1d388yEQ
Meanwhile Sydney’s main water storage, Warragamba Dam is overflowing, for the firs time in *gasp* 4 years. I think that’s how dams normally work.
Another case of ignoring facts to advance a theory.
My dam in south east Queensland filled only twice in my first 23 years here.
It has filled 3 times in the last 5 years.
I’ll take as much of this global warming as I can get
Folks, Keith is not exaggerating.
As at 17 Aug 2020 at 13:330 (see https://www.waternsw.com.au/supply/Greater-Sydney/greater-sydneys-dam-levels)
– Warragamba dam (capacity 2.017 Gigalitres) is 100% full
– the other dams (about 0.5 Gigalitres are nearly full.
The whole Sydney system is 98.2% full.
And we regularly hear Tim Flannery or other Greens saying “we’ll never see Warragamba full again” and if the science is settled and the land is drying out, how come the dams do get full again? Not good enough just to say that such will not happen again in the future.
Let’s see the detailed theory
Let’s see the model
Let’s see the data
Let’s see the peer review results (so we know who else to mock!)
It’s not just that they’re full but that they’re full in a hot year.
The whole hypothesis is flawed.
Firstly anyone who is a devotee of the Flannery rainfall theory immediately identifies themselves as an idiot, just like Doctor Whats-Her-Face above.
Having said that, it equally gets up my nose when a lot of the Oz commenters here say that their tank or local dam is overflowing and then proceed to extrapolate that to the whole country.
The dams west of the Dividing Range in NSW are by and large still in dire straits:
Carcoar 21.5%; Chaffey 24.7%; Copeton 15.5%; Keepit 22.4%; Menindee 26.5%; Oberon 25.9%; Pindari 16.0%; Split Rock 4.9%.
These are major dams for town water supply and irrigation and cover a huge area. Don’t assume that what is happening in your backyard is happening everywhere. The fact that Warragamba is full is nice, but an irrelevance to everyone except Sydney-siders. Warragamba ain’t Australia.
https://www.waternsw.com.au/
Warragamba is also the most “recently” built dam serving Sydney. I’ve put “recently” in quotes: it was completed in 1960.
Since then Sydney’s population has risen from 2.1 million to 5.3 million, yet no new dams are even contemplated. Ergo the problem isn’t filling, it’s the emptying, because the politicians have refused to match growth with necessary water infrastructure construction.
The only way that CO2 could warm the world more than half a degree Celsius is through positive water vapour feed back.
This is unproven and the tropical hotspot has also never been located .
Both of these factors have to come into play to make a difference to the worlds temperature.
Even if these factors are proven to exist more water vapour means more rain and less droughts .
You cannot have it both ways .
CO2 does not control the weather and if a little more warmth results a little more water evaporating from the oceans a warmer atmosphere holds more water vapour to fall on the land .
Weather records around the world going back as far as they have been kept show no pattern of more droughts and more violent tropical storms .
What is wrong with these people ?
They are speculating with absolutely no proof to back up their theories of doom and gloom.
Defund the Universities might be the way to go.
Graham
“Tired Climate Change Myth”?
Great phrase!
Thank you.
There are so many of those!
A much needed phrase in any discussion about the climate movement.
Another tired climate change myth is that our fossil fuel emissions are melting ice shelves in Antarctica. This stuff normally flows out of Columbia University, the UNSW of the North, but the latest such alarm is from UC San Diego that has not really indulged in the climate game in the past.
Anyway, now that we have ICESAT2 ice shelf data, expect a renewed torrent of ice shelf alarms in the journals. Here is one …
https://wp.me/pTN8Y-42D
It has already started. BBC in January:
https://www.bbc.co.uk/news/science-environment-51097309
My favourite quote from the piece, referring to “a degree or two” warmer water:
“It can set glaciers on fire,” says Prof Holland, “increasing melt rates by as much as a hundred-fold.”
I have made a note of your name, “Professor” Holland..
It’s funny that you post this now, because as you speak, the dams in Sydney are at 100%.
Hot dam!
Oh yes but climate change starts ………NOW! …… no I mean………NOW!!
So she got her 15 minutes of fame and now what?
“Youth is wasted on the young”.
Youth is a trick played upon the young to make more young.
The Australian Bureau Of Meteorology (BOM) have graphs of rainfall in Australia.
http://www.bom.gov.au/climate/change/#tabs=Tracker&tracker=timeseries&tQ=graph%3Drain%26area%3Daus%26season%3D0112
The 1900 – 2019 data shows:
Australia – trending UP
Eastern Australia – steady
Northern Australia – trending UP
Southern Australia – trending UP
Southeastern Australia – steady
Southwestern Australia – trending DOWN
Murray Darling Basin – steady
It’s no wonder there are people such as myself who doubt the messages coming from the doomsters when reality is at such odds with the models and their doom-mongering prognostications of climatageddon.
How do these people actually remember to breathe?
There’s an app for that.
Or cross the road unaided?
Academics are the equivalent of soothsayers and jesters employed by the monarchy in the days of yore. They use computer models instead of crystal balls. Some paid a heavy price when too many predictions didn’t occur.
Please do not lump smoothesayers and jesters together. The smoothesayers are like many of our modern worthless politicians and self-(en)titled scientific experts. However, jesters not only entertained but were able to use humor to make pointed political criticisms without offending “a not too bright” king. We could learn some useful lessons from jesters on how to discredit alarmists by making fun of them. 🙂
My climate grant for a new and improved self sharpening kind of guillotine has been approved for climate deniers. I just didn’t tell them that the real deniers are the climate scientists making all this crap up with crystal balls (computer models) Ok, a bit of sarc/ if I really need it.
https://www.linkedin.com/in/steven-mosher-27bb071/ Steven Mosher who went over to the dark side to work for or assist Richard Muller at Berkeley in the BEST temperature data set ; now calls himself a data scientist.
” now calls himself a data scientist”
Self-satire ?
or just self-ridicule !!
So Steve has a computer science degree now?
How to shut up an academic–you make them PERSONALLY RESPONSIBLE for their predictions. If Ms. Stephens wants to make predictions like this, build dams 10 feet lower but then she has to pay the price if she’s wrong. My expectation is that many models–including the IPCC’s–will wither once monetary accountability of the modeller becomes involved.
I too found the inverse of common experience of water falling on dry soil puzzling–has she never actually been out in the rain? It does depend on how the rain comes, but ‘downpours’ on dry soil quite clearly from practical experience results in increased runoff relative to moist soil; any of us who have had to shoulder the responsibility of logging-road and cut-block design know that one all too well. That reverses once soil becomes saturated and a ‘downpour’ occurs, but she is suggesting the opposite conditions for her model–a standard condition of drought punctuated by ‘downpours’. There is indeed an indication of there never having been soil under the fingernails, dry or wet.
Incidentally, I like many of you note the increase in the use of the ‘suggests’, ‘might be’, ‘may’ weasel words in so much of modern ‘science’. I remember wrestling with the use of these terms first in theses as far back as the 1960’s, and in many reports to clients since. I came to the conclusion long ago that they had no place in any report of mine; I could say that something ‘was’, or ‘wasn’t’, or that ‘I don’t know’, which means shut up about it and go do more work before expounding. How did we ever let anything that ‘might be’ science become so much of science?
That, plus rampant un-accountability, has produced an endless supply of academics peddling pointless pedantry.
Apparently the educational system in AUS is as bad as the US. Not a clue about the past history for this “academic”. Get a real productive job miss!
This is probably the zenith of her career. Being featured on the most popular climate sceptics site is something of an achievement.
Obviously Clara is on “man made climate change” benefits.
Surely the ‘ man ‘ needs to be changed for sexist reasons.
Any ideas ?
Obviously Clare is on “man made climate change” benefits.
She looks as Australian as a pie floater.
Certainly not like your local sheila down the pub. More like a footie WAG.
Pretty face, empty head.
And what is there is nonsense from a failed education.
Sad.
One of the predictions of anthropogenic CO2 global warming was that the CO2 increased the greenhouse effect, amplifying the evaporation of water vapour from the oceans and dams. Water vapour being a bigger component of the atmosphere, then trapped more heat warming the oceans, creating more evaporation and water vapour in the atmosphere.
The reality of the hypotheses is that this will lead to potential run away warming, hence the wide range of scary results on the climate models.
However the feedback should be greater precipitation due to convectional cooling, cloud formation with resultant rain.
The models have not got a handle on clouds.
After all, more greenhouse water vapour, quicker response by convection, more precipitation.
Seems fairly reasonable.
Looking back to the belief stage of my life, when Al Gore told us that rainfall in Australia would fall, you can see how hard it is for me to remain a believer.
Rainfall in Australia’s North increased.
Despite a wicked Australian drought, the dams all filled in my area in the last month.
It seems that the Indian ocean dipole has a real effect, so models have to include ENSO and IOD.
https://www.waternsw.com.au/supply/Greater-Sydney/greater-sydneys-dam-levels
Warragamba in NSW is 100%.
if you dig into the soil the subsoil is as dry as dust, yet the water ran off.
In the 80s and 90’s we had our ‘100 year flood’, almost twice.
Where it comes to models, it would be good to see if they work to predict rainfall and evaporation say from
1880 to get a good idea of drought and rainfall in Australia.
My tank also filled twice over.
We need more storage in Warragamba to prevent another flood.
There are too many people in the Hawkesbury that are at risk when it spills.