For Like minded people who like to see-
The cost to Australia.
Predicting the future is not possible. There are too many variables. What we can do is have a look at the importance or place, of Western Australia agriculture to the national agricultural economy in recent times and from that information extrapolate the financial impact on agriculture in Australia by the loss of 17 million hectares to salinity by 2050.
If the predictions are correct and we are in danger of losing an area the size of the agricultural region of WA to salt by 2050; based on current production, we will lose 15% of Australia’s gross value of agricultural production to salt by 2050.The current cost to Western Australia.
In 2001, Short and McConnell of Agriculture WA, in their paper ‘Extent and Impacts of Salinity’ calculated the annual cost of salinity to the economy of the South West Land Division of Western Australia to be between $661million and $1.4 billion. That was ten years ago — what is it now?
They also concluded: The datasets suggest that current and perceived future land uses will result in approximately one-third of the south-western agricultural areas being affected by shallow watertables and salinity. This will potentially affect about 30,000 km of road and rail networks and at least 27 major rural towns. Surface water resources in the south-west of the State are likely to become more saline. The impacts on biodiversity are only just starting to be appreciated, but it is estimated that at least 1500 plant species will be affected, with 450 subject to extinction. Salinisation is also likely to reduce fauna species by 30% in affected areas. It is estimated that around 6.5 million hectares of agricultural land will be subject to shallow watertables and salinity.
Short and McConnell – Extent and Impacts of Salinity.
How big is the problem – what is the proof?
“Dryland Salinity is Australia’s biggest environmental problem”. ‘This was an often stated claim until a few years ago. Such an exaggerated claim was self-defeating for the protagonists involved. Disappointingly public policy and funding priorities reflecting this mindset continued for years beyond compelling evidence pointing to a needed change in strategy. For many reasons dryland salinity in Australia is perceived now to be a problem of the past.
‘In fact, dryland salinity is still a major economic, environmental and social problem and there are still significant benefits from investing in a new strategy. There have been celebrated successes in reversing its impact on rivers and streams; yet dryland salinity has proved to be an intractable problem for farmers and land managers.
‘Salinity management has been a galvanizing force for integrated catchment management and the Landcare movement over more than 20 years. The recommended new strategy targets public investment on salinity management actions for the highest value natural and built assets, while adapting to salinity where it is already occurring, and boosting R&D into farming systems that are more robust under greater climatic variability.
‘Separating fact from fiction.
‘Current extent and predicted impacts of dryland salinity in Australia have been prone to exaggeration, misreporting and poorly validated modeling; to the point that the ensuing debates have distracted landholders, communities and governments from committing to a sustained and effective strategy.
‘Today the best estimate for currently salt-affected land in rural Australia is 1.9 million hectares; and 1.1 million hectares in Western Australia (George 2008). This aggregate figure comes from a reassessment by State government senior hydrologists, drawing on techniques refined over several years.
‘A valid aggregate figure for the likely rise in salt-affected land in the future is not possible; however a rough estimate of 3.7 million hectares nationally – about half in WA – has been provided as part of the same state-by-state reassessment.
These figures are much lower than past estimates of threat for two reasons: the dry climate sequence has resulted in previously rising water tables slowing, ceasing or even reversing; and the methodologies and data for past estimates have been inadequate. The lesson from this is that the science base for assessing salinity trends and predicting threats must continue to be developed.
‘The National Land and Water Resources Audit’s Australian Dryland Salinity Assessment 2000 (NLWRA 2001) attempted a comprehensive assessment of area at risk from the best information available from the States and Territories. It explicitly described the information and methodology
‘It estimated that “approximately 5.7 million hectares are within regions mapped to be at risk or affected by dryland salinity. It has been estimated that in 50 years time the area of regions with a high risk may increase to 17 million hectares.’
Kevin Goss. Confronting Salinity:…
It is of interest to note the comment from Goss: These figures are much lower than past estimates of threat for two reasons: the dry climate sequence has resulted in previously rising water tables slowing, ceasing or even reversing…
In the last twelve months, big areas of Queensland, New South Wales and Victoria have been flooded which will raise the water table and so reverse the effects of the dry period. Is that a reasonable assumption? If it is, see below:
State areas at high risk from shallow watertables or with a high salinity hazard.
State 1998/2000 2050
New South Wales 181 000 1 300 000
Victoria 670 000 3 110 000
Queensland not assessed 3 100 000 #
South Australia 390 000 600 000
Western Australia 4 363 000 8 800 000
Totals 5 650 000 17 000 000
Australian Dryland Salinity Assessment 2000.
Natural Heritage Trust.
# The predictions for Queensland according to a Queensland source within a government agency, who prefers not to be named, believes the Queensland figure should be taken with ‘a pinch of salt’. It appears that Queensland doesn’t really know what the extent of salinity is in that State.
Relax - We have a plan.
Industry recognizes that scientists are not marketers nor are they trained to sell product. Their job is to invent and develop products.
Whatever the product there is always competition for the consumer’s dollar. Good marketers employ market research so they may understand what motivates their potential customers. Good marketers are good communicators. Good marketers exploit the media.
The final judgment comes when the market, the customer decides whether it wants and more importantly whether it can afford the product.
For more than forty years I have attended field days, seminars and demonstrations showing the results of research into what we can do with our salt land to make it productive. The presentations have invariably been made by scientists.
Over that time I must have read hundreds of research papers, which discuss the problem. Not all the researchers agreed with each other. In the main the differences were in the detail. What they did all agree on is that the water table is rising over the majority of the South West Land division of WA and the area affected by salt will continue to increase.
Hundreds of millions of dollars have been spent on this research and on community initiatives, yet the area of salt affected land continues to grow, seemingly unabated.
The products of this massive public investment have not been adopted or bought by landowners.
As we shall see, sophisticated market research has revealed the reason why.
I well remember the many toe-to-toe arguments in the 60s and 70s between farmers and scientists regarding the effectiveness of Whittington Banks of various sizes and configurations. A lot of farmers built ‘Whittington Banks.’
It is interesting to note that the majority of the ‘Whittington Banks’ are still there. That can only mean one of two things:
I suspect the latter.
There have been and are convincing demonstrations of the beneficial effects of drainage to combat salinity. The trouble with drainage is that it’s just that— drainage. The salt water has to go somewhere and drains cost an enormous amount of money and as we will see, that cost is far beyond the means of the average farmer.
In 2002 there was a National Action Plan (NAP) produced for salinity:
National Action Plan for Salinity and Water Quality.
Results from the 2002 Land Management and Salinity survey are presented in terms of the National Action Plan for Salinity and Water Quality (NAP) regions. The NAP is a joint project between the Commonwealth and State and Territory Governments adopted primarily to address dryland salinity. The Goal of the Plan is to motivate and enable regional communities to prevent, stabilise and reverse trends in dryland salinity and to improve water quality. It identifies 21 high priority regions across Australia.
Nationally the NAP regions account for 17,000 farms, or 87% of total farms showing signs of salinity. And 1.3 million hectares or 66% of the total area of land showing signs of salinity. The map (not shown) presents the five Western Australia NAP regions (Avon, South Coast, South West, Northern Agricultural Region and Ord) shaded according to the salinity in the area.
Region by region the number of farms affected by salt in Western Australia is alarming. As a percentage of the total, the number of farms affected by salt in the South West Agricultural Region is:
Avon: 76% to 100%
Northern and South Coast: 51% to 76%
South West: 26% to 50%
Ord: 0% to 25%
Those numbers cause me to question whether the predictions for the increases in salinity in the future are correct.
Just have a look at those numbers and those regions again and maybe, again. Those are the regions where Western Australia grows its grain and is producing the majority of its meat and wool. Western Australia provides 80% of Australia’s export grain.
Hi Roger interesting stuff.
Perhaps you can help me here. Am I correct in believing that as the water table level raises this is what transports the salt to the surface, and that a lower water table reduces salinty.
I ask because one of the meeting I attended in Mt Compass regarding the preposed water action plan for the eastern mount lofty ranges. The hydrologist stated quite clearly that salinity was rising as a result of the water table lowering.
I did some searching and found a document "Salinity – the awakening monster from the deep" which clearly conflicted with that view.
Look forward to your reply.
It's a complex one and there is no absolute answer to cover all soil types, rainfall zones, climates (rate of evaporation) and so on.
Salinity is not just a problem in Australia, though we are probably (in area) one of the (potentially) worst affected.
There are also areas around the world and in Australia which have been salt for thousands of years.
Salinity in Australia has increased in direct proportion to the speed at which we cleared the land. Some of the salinity takes 50 years to emerge, this is the conundrum facing Qld, why no one will talk about it. The 3.1m hectares that went into the study was based on a map, as I understand it, with pink patches on it that measured 3.1m/ha where the water table was rising.
Fresh water sits on top of salt water. Use up the fresh and you are left with salt.
In WA and I suspect SA the winter rainfall has been decreasing over the last fifty years, statistical fact.
We have cleared the land and grown, largely, annual crops.
Natural forest kept the water table down and encouraged rainfall. At least if you cut the trees down and the rainfall decreases, then that is a reasonable assumption, that was the hypothesis which has now been shown to be 'true'.
So as a result the hydrology hasn't so much changed, its just that we have used up the fresh water and the saline water is now at the surface.
In Vic they thought that salinity might regress due to the 10 year drought. I believe they are no finding that with the profile full soil again, salinity is reemerging.
The other thing that makes it complex is when you see salinity progressing up hill.
I am and will never claim to be a hydrologist. All I can do is look at the numbers, even watch the country I know so well, and note the change.
It gets more interesting this story (I think) as it goes on. It was too long to put up as one article.
If the scientists are right and there would be many farmers in WA who would agree with the estimate, 17m/ha is a very frightening prospect.