Tuesday, October 24, 2006

Australia's greatest drought - or is it our wettest period on record?

As noted in my story Water, Drought and the Environment - working from facts I had been under the impression that Australia was presently experiencing perhaps its worst drought, by implication its lowest rainfall, on record.

I was surprised and very interested to find from a story in the Sydney Morning Herald (21-22 October) that data from the National Climate Centre shows that the period October 1996 to October 2006 when averaged across Australia was in fact wetter than the long term average. Further, the period 1997 to 2001 was the second wettest five year period in Australian history.

How do we explain this apparent contradiction? It appears there were two Australia's during this period. The south eastern third of the country has been getting hotter and drier. This is where most of the people live, hence the overall perception. However, the north western half of the country has been getting wetter with some areas experiencing the highest average rainfalls on record.

What does all this mean? To begin with, we have to be careful with averages since they are affected by start and end points. I was not able to check all the data because it's not available on line without purchase. However, if you follow the link above and play round with maps and data (this is quite fun) you will see what I mean.

But beyond this, it again illustrates the need to check facts. The present debate on water is being driven especially by the problems in the south eastern corner of the country. Can that experience in fact be generalised to cover the whole country?


Anonymous said...

Interesting observations. I notice on the news they often show properties around Condbolin, but it is fair to say that has always been a marginal area; they also show the situation around Orange/Molong, an area I am more familiar with, and it is bad there for sure.

Can the phenomena you allude to justify the idea of rethinking what parts of Australia might be "abandoned" and what parts might be open to agriculture? (The kind of thing advocated recently by the Australia Institute.) Politically, socially, and personally for those involved it is a real minefield.

Any thoughts?

Jim Belshaw said...

Thanks for this, Neil. I do not think that many parts of Australia have to be abandoned as such, but there will be changes.

The problem at the moment is that we simply do not know enough to distnguish between short and longer term trends. But if I had to guess.
1. Sydney will be okay because it can afford desalinisation and also has scope to collect more from run-off in the immediate area. The main effect in Sydney will be higher prices for water.
2. Real estate prices in New England, the north east corner, will increase because this is the wettest part of NSW. A big issue will be the extent to which New England easterly flowing waters should be diverted to SE Queensland or into the Darling system.
3. Agricultural activities - cropping and grazing - in NSW will contract to better suit water levels. This will be most pronounced in the central and southern parts of the state.
4. Melbourne will be okay but at higher water prices because it can afford desalinisation. Agricultural activities in Victoria will contract.
5.The SA desert areas will increase in the south. Depending on the quantity of water diverted into the Darling, Adelaide may need to go for desalination.
6. There will be a major national program equivalent to the Snowy to divert Northern waters to the south. Population will shift.

But all these effects will take time. This drought will end in major floods as has happened before.

There you go, for what it's worth.

Travel Italy said...

Jim - It is like the economy. How can we have tremendous growth and the general economic situation of individuals deteriorating...

It may be a variation on "What is good for the Goose may not be good for the Gander."

Jim Belshaw said...

An interesting comment, David. I think that you are right.

The just released IMF report on the Australian economy gave us a positive report card with growth set to continue. The Government is trying to push more people into work by tightening up on benefits arguing that the economy is good.

Yesterday the Australian Dental Association said that 40 per cent of Australians can no longer afford regular dental care. Many Australian's are struggling to make ends meet with some middle class families seeking food aid from charities. Older Australians in particular are struggling to get any form of work.

Two Australia's. Some talk back radio callers suggested that the problem was that our key policy makers and leaders in secure positions could not actually see the problems generalising from their own experience in much the same way that the water debate is driven by SE Australian experiences.