Jennifer Marohasy

a forum for the discussion of issues concerning the natural environment

Floods

Rainfall Forecasts Should be Benchmarked

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ACCORDING to Bill Gates, “You can achieve incredible progress if you set a clear goal and find a measure that will drive progress towards that goal.” This may seem basic, but it’s not practiced enough, and certainly not when it comes to rainfall forecasting.

John Abbot's corvette which was submerged in the Brisbane flooding of January 2011.
John Abbot’s corvette which was submerged in the Brisbane flooding of January 2011.

The Bureau of Meteorology increasingly use their weather and climate forecasts to warn of looming catastrophe. This use of ‘forecasts’ to advance an agenda is common in politics, but it’s not something the Bureau should be engaged in.

A key Bureau goal should be the best possible rainfall forecast for the public. Their rainfall forecast should be presented and reported in a measurable and understandable way. Instead we are given vague probabilities, which research has shown are often misinterpreted by farmers.

Furthermore, there should be some follow-up. For example, at the end of a week, a month, or a season we should be told how reliable their daily, monthly and seasonal forecasts have actually been.

Its five years now since Brisbane flooded, so about five years since I started working with John Abbot and artificial neural networks to see if was possible to actually forecast the extraordinary wet season of summer 2010/2011 in south eastern Queensland.

Back in 2010, sea surface temperature and sea surface pressures profiles across the Pacific suggested we were in for a big wet. Yet the Wivenhoe reservoir upstream of Brisbane, a dam actually built for flood mitigation, was kept full of water.

John Abbot’s little red corvette sports car was drown in the Brisbane flood. It was in a river-side garage in St Lucia, Brisbane, and totally submerged for 36 hours. He was heartbroken. The loss spurred us to see if we couldn’t apply the technique he had used to make the money to buy that car, to rainfall forecasting. In particular, we were keen to see if artificial neural networks with the right algorithms, and high quality historical temperature and rainfall data, could have forecast the flooding. John Abbot regularly used artificial neural networks and historical trading data to successful forecast directional trends in the share market.

By August 2011 we had monthly rainfall forecasts for 20 sites across Queensland, and we wanted for compare our output from the best general circulation model (POAMA) used by the Bureau of Meteorology. But try as we might we couldn’t actually get the taxpayer-funded Bureau to give us the data we needed to make proper comparisons.

The Bureau were not doing the one thing that Bill Gates says is critical to improvement: benchmarking.

After flying to Melbourne, and threatening to jump out a sixth floor window if the data wasn’t handed over (well I exaggerate somewhat), we got access to only enough data to enable us to publish a series of papers. Indeed, the Bureau still refuses to make available the most basic of data which would allow their rainfall forecasts to be objectively scored.

Back in 2011 it was evident that John Abbot and I could do a better monthly rainfall forecast than the Bureau. To our surprise key science managers at the Bureau agreed: conceding that our forecasts were more skillful. But, they argued, climate was on a new trajectory so our method would not work into the future!

This claim is, of course, based on the theory of anthropogenic global warming. This is the same theory that continues to underpin all the forecasts provided by the Bureau through the use of general circulation models.

An alternative approach using artificial neural networks, fits under the umbrella of ‘Big Data’ and ‘machine learning,’ that relies on pattern analysis, and is proving successful at forecasting, where results are properly benchmarked, in fields as diverse as medical diagnostics, financial forecasting and marketing analysis.

I will be in Deniliquin, NSW, on Friday 26th February, showing both temperature and rainfall data for the Murray Darling region that indicate our climate is not on a new trajectory. I will also be explaining the principles of rainfall forecasts using artificial neural networks, and making some forecasts.

I will also show how proxy data giving an indication of climate change over the last 2,000 years can be deconstructed into sine curves. Seven sine curves of different frequency and amplitude potentially corresponding to natural climate cycles driven by variations in the Earth’s orbit and solar activity (e.g. magnetic field) can be used to generate a sinusoidal projection, suggesting future global cooling. Cooling in the Murray Darling Basin is typically associated with period of below average rainfall.

Five sine curves which can be fitted to proxy data corresponding to a temperature reconstruction from a South African stalagmite.
Five sine curves which can be fitted to proxy data corresponding to a temperature reconstruction from a South African stalagmite.

The information session is being held by West Berriquin Irrigators at the local Deniliquin RSL from 6pm. RSVP to Linda Fawns on 0409 044 754 or westberriquinirrigators@gmail.com.

Environmental Flows in the Murrumbidgee Irrigation Area: Debbie Buller

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Following is a note and link to photographs from a Murrumbidgee farmer with a rice crop that is withstanding the deluge, but she can’t say the same for the orchards and vineyards that many misguided folk in Sydney would prefer to see growing in our land of drought or flooding rains…

Hi Jen,

Here are some photos showing the extent of the flooding in the Murrumbidgee Irrigation Area.

http://www.mirrigation.com.au/Flood_pictures_March2012.htm

I want everyone to know that this is clearly showing that the flood plains that we live and work on and that we are therefore custodians of, have precious little to do with the Murrumbidgee river.

The river is not flooding here yet, and the majority of what you see here will not flood when the river peaks at Narrandera and Darlington Point in the next few days. The exception will be the Roache’s escape photo because that may not clear before the river rises. It would not normally flood there but it may still remain backed up.

There is extensive damage here and the water will hang around for longer than the river flood waters.

I can already hear the PR babble from the ‘political agenda’ that this is unprecedented and that there is nothing that could be done other than follow their impractical rules.

Let me assure you that is not the case and those who possess generational knowledge knew exactly what was about to happen once those heavy rains started belting down onto the already saturated surrounding hills and ranges.

It has happened before and will no doubt happen again.

That is why it’s so flat here. That is why we have expanded and enhanced our flood plain wetland ecology here by developing the MIA.

That is why our forefathers had the vision to develop this area.

We will also clean up the mess and move on as we always invariably do.
I am very curious to know how the 3 major MDB rivers flooding yet again will impact those ‘end of system flows’.

I am also wondering how the Murray Darling Basin Authority, CEWH, New South Wales Office of Water, Snowy Hhydro Ltd et. al. will attempt to justify storing environmental water and enhancing flooding events under the current conditions.

I’m positive all those Ramsar birds are completely ignorant of the fact that they have apparently been assisted by the Federal government and actually I’m positive they never cared.

At the moment, our area looks like it could be used as a setting for the Hitchcock movie ‘The Birds’. Not one cent of taxpayer money or current water policy had anything at all to do with that.

Our own highly variable and highly unpredictable land ‘of drought and flooding rains’ has just proceeded to solve all the stated problems in the current political ‘water reform’ agenda all by itself.

They do not have a practical plan or a sensible management principle to cater for the blatantly obvious ‘other side of the coin’ let alone the fact that they can’t produce water out of thin air or run the Murray in a severe drought as if it was a pressurised pipe.

There is no joy however in claiming ‘we told you so’

It would be wonderful if our current crop of politicians and bureaucrats would actually recognise that most of what we already know and most of what we already have done recognises the need for flexibility.

Instead we are watching them all scramble to protect their position and protect their inflexible and counter productive rules.

Parochial politics is dismissing what we have all learned. It is also highlighting the mistakes we have not fixed yet instead of allowing us to fix them. I will also add that most of the mistakes, including over allocating unregulated river flows and refusing to upgrade or finish existing infrastructures (including those SA nightmares) were made by poor government policy, not by the people who live and work there.

The majority of the rice crops are fine. Ours look magnificent and they’re hosting a cacophony of native wetland species. Strangely, as we all knew, they all came back when the drought broke. Even the supposedly extinct ‘brown bitterns ‘ and numerous other supposedly endangered species of frogs, birds etcetera.

The same cannot be said for those ‘high value’ permanent plantings that the Wentworth Group et al have loudly claimed (until very recently) were much more efficient and cost effective crops to produce. Those crops are in severe trouble and some have been irreparably damaged.

As I said, there is no joy in trying to be smug. There is a part of me however that wants to dump those ‘concerned scientists’ right in the middle of Yenda.

There are a lot of people here who will need help and support. More still will be flooded out by our river in the next few days.

I sincerely hope the current political agenda does not further damage their fragile self esteem as it has done by misrepresenting them as ‘environmental vandals’.

Any who read this and are struggling with the flooding, I am thinking of you and hoping that you and your hard won assets manage to get through and survive so that you can continue to be the productive custodians of our beautiful but harsh land that you always have been.

Debbie Buller
Murrami, Murrumbidgee Irrigation Area

More Flooding

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Large areas of Queensland and New South Wales are flooding again.

In New South Wales:

Flood Warning – Clarence River,
Flood Warning – Bellinger River,
Flood Warning – Hastings River,
Flood Warning – Manning River,
Flood Warning – Orara River,
Flood Warning – MacIntyre River,
Flood Warning – Gwydir River,
Flood Warning – Peel-Namoi Rivers,
Flood Warning – Castlereagh River,
Flood Warning – Culgoa-Bokhara-Narran Rivers,
Flood Warning – Warrego River,
Flood Warning – Paroo River,
Flood Warning – Barwon-Darling Rivers,
Flood Warning – Paterson-Williams Rivers,
Flood Warning – Nambucca River.

In Queensland:

Flood Warning – Burdekin River,
Flood Warning – Fitzroy River,
Flood Warning – Condamine-Balonne Rivers,
Flood Warning – Macintyre/Weir,
Flood Warning – Moonie River,
Flood Warning – Nebine/Wallam/Mungallala,
Flood Warning – Warrego River,
Flood Warning – Paroo River,
Flood Warning – Bulloo River,
Flood Warning – Thomson/Barcoo/Cooper Ck,
Flood Warning – Western Queensland Rivers,
Flood Warning – Gulf Rivers.

http://www.bom.gov.au

Lake Eyre, Still Flooding

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For the last three autumns, Lake Eyre in central Australia has received runoff from good flooding rains.

These photographs were taken by Rhyl as she flew from Quilpie to Birdsville to Lake Eyre in July 2010.

And the flood waters are arriving again this year.

Wild flowers as a mass of yellow from the air.

A land of patterns, according to Rhyl.

Click on each image for a better view.

Black Water Kills Tens of Thousands of Murray Cod

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Yesterday, Wakool farmer John Lolicato told me about recent fish kills in the southern Riverina.   Click here to listen to our conversation: WS450079   

The fish kills were caused by black water with tens of thousands of Murray Cod dying over the last four years.  

The enormous (1.4 metre long) Murray Cod being held up by two farmers is just one of many large fish found floating in the Lower Wakool River following a black water event last year.

The Wakool is an anabranch of the Murray, click on the map for a better and larger view.

A Land of Drought or Flooding Rains

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EASTER Sunday in 1915 the community of Murrabit in the Central Murray Valley gathered for a picnic at a farm called Riversdale.   It had been so dry that the Murray River had run dry. 

 A photograph was taken of the buggies in the dry river bed. 

Today, March 9, 2011, I visited Riversdale and took a photograph of the Murray in flood.  

The third photograph shows me looking across to the exact spot where the buggies were parked in 1915. Water now extends for another 5 miles beyond the far river bank into the red gum forests.