Mapping Salinity: What a Mess

Two weeks ago I received an email from Rob Gourlay letting me know that Brian Tunstall’s response to the 2005 Spies and Woodgate Report on salinity mapping methods was available at the ERIC website.

Some of the issues Brian Tunstall raises in this review, include the same issues that I raised in my Land column of May last year, titled Challenging Belief on Dryland Salinity in which I wrote:

A recent released technical report, Salinity Mapping Methods in the Australian Context (January 2004), from the Australian Academy of Science restates the cause as ‘changes in the water balance of landscapes following the removal of native vegetation and the introduction of European agricultural practices’ (pg. 8).
It predicts that the area affected by dryland salinity will continue to increase because of continuously rising saline water tables from the changed water balance.

This basic premise, however, was challenged by NSW government scientist Dr Christine Jones, who had articles published in The Australian Farm Journal in 2000-2001.

She contends that the ‘rising groundwater model’ has failed us because it makes false assumptions about the nature of pre-European vegetation and the way water moves in the landscape.

Rob Gourlay and Dr Brian Tunstall of Environmental Research and Information Consortium Pty Ltd (ERIC) independently came to similar conclusions through the development of an airborne gamma radiation salinity mapping technology.

According to Gourlay, ‘Dryland salinity (in the Murray Darling Basin) is really a soil health issue, a symptom of soil degradation not a rising water table issue.

The Academy of Science report compares salinity mapping methods with the conclusion that the main ‘knowledge gap’ is the location of salt at depth and whether it is likely to be mobilised by rising groundwater.

The electromagnetic (EM) mapping technique that the report advocates for plugging this knowledge gap is expensive—up to 10 times the cost of doing the gamma ray mapping that focuses on the top metre and that Gourlay has commercialised.

The Academy of Science report was dismissive of the gamma ray technology for salinity mapping describing it as not having a scientific foundation and advising potential users of the technology to seek ‘independent advice on claims made by the vendors’. Gourlay regards this as an attack on his ‘professionalism and capacity to trade’. He questioned how ‘publicly funded scientists who compete with the private sector can get away with using taxpayer money to discredit the only technology that has delivered benefits to clients at a paddock, farm, catchment and regional scale across Australia since 1992’.

One of the authors of the Academy of Science report, Brian Spies, works for the CSIRO and has been involved in the development and commercialization of the TEMPEST electromagnetic mapping system.
CSIRO provides commercial services based around the TEMPEST technology and hence the Australian Academy of Science report could be interpreted as knocking a competing service as well as promoting the CSIRO method.

The saga drags on.

It is interesting to reflect back to November 2000 when the Council of Australian Governments endorsed the National Action Plan for Salinity and Water Quality with a funding package of $1.4 billion over 7 years.

As part of this package state governments produced a series of salinity hazard maps.

On 2nd August 2002 industry representatives gathered with media at The Salinity Summit at Queensland’s Parliament House to hear speeches from State Premier Peter Beattie, Federal Minister for Environment and Heritage Hon Dr David Kemp and others.

The Premier’s speech included:

“The first thing that we have to avoid is denial, and I am going to come back to this. The first thing we have to avoid is denial about the problem. There is a problem. … We have to accept there is a problem, and denial is not on the agenda. It will not be on the agenda. It cannot be. We have got an action plan where all the stakeholders have a say in the solution. …I want to make it clear that we stand by the science in the map. Its methodology has been checked and endorsed by the CSIRO, the National Land and Water Audit and AFFA. As I said before, I want to thank Dr Kemp for taking this constructive approach and lending this support to our science …” (pg. 2)

A lot of government policy decisions, and government dollars were allocated, on the basis of the map the Premier proudly displayed that day. The map was all over Brisbane television that evening.

Ian Beale (a local landholder with a PhD) was reported in the Queensland Country Life (QCL) explaining that according to the government’s own Salinity Management Handbook (QDNR 1997) the area west of the 600mm isohyet could not be at risk of dryland salinity – yet is shown on the Premier’s map as bright red and therefore at high risk. The map with the isohyte marked by Beale can be downloaded here (600 Kbs).

This map that the Premier had proudly displayed at the summit, but with the isohyet as drawn by Ian Beale, was published in the QCL.

In March 2005 at the Australian Water Summit in Sydney I listened to a speaker from Geoscience Australia explain how technology used by the Queenslnd government to develop the salinity hazard maps and other maps used in catchment management planning were based on old technology. I queried this during the question session and Brian Spiers (a member of the Conference audience) volunteered that the Queensland scientists who put the original maps together were not skilled in the technology that they were using. This includes the map Premier Beattie said he stood by at the Summit and that he said CSIRO had endorsed.

Meanwhile Tunstall and Gourlay continue to explain how CSIRO has got it so wrong with the new review at ERIC. Tunstall summarizes part of the problem:

… This error could reflect deficiencies in the
presentation of hazard and risk in the report as, while hazard is implicitly identified as being categorical, this was not explicitly
stated. However, it demonstrates the limited ability of those producing the report [and maps] to integrate the disparate information it contains. If the information in the Report is inadequate for the authors to draw correct conclusions then it would be considered grossly inadequate for those that are meant to use it. If the authors get it wrong from the material presented then it
would be reasonable to expect that most people will get it wrong.

This inability to integrate diverse information derives from a failure to apply basic scientific considerations such as the
form of variable (e.g. continuous variable or category), independence of observations (the advocated use of information that is
not independently derived results in circular arguments) and mutual exclusion between categories. This latter condition is illustrated by the failure to discriminate between soil water and ground water, and
the apparent confusion between geology and hydrology.

…………
Relevant documents/links:

Peter Beatties speech at the Salinity Summit,
Download file .

The Spies and Woodgate report, (I am having trouble uploading my copy of this report, perhaps someone can send me a link? 19/9 at 6.30pm) (4,000 Kbs).

The Tunstall report at ERIC, Download file (678 Kbs).