Tag Archives: Pilbara

Beneath the surface

CSIRO scientists have revealed how much water lies beneath the surface of the parched Pilbara landscape in a study to help safeguard the resource as mining and agriculture expands in the region and the climate changes.

The $3.5 m Pilbara Water Resource Assessment project found the area’s extreme heat evaporates up to 14 times more water than falls as rain – highlighting the region’s dependence on groundwater.

The work also revealed 8–30 mm of rainfall is required to make the rivers and streams flow, and that the region is getting hotter and drier in some areas and wetter in others.

CSIRO hydrologist and study leader Dr Don McFarlane says researchers now have a framework to study the impacts of mining and better manage local water use.

The mining industry abstracts about 550 gigalitres of water a year in the area and half of that is used for ore processing, dust suppression and consumption.

Beneath the surface
Iron ore being transported by rail in the Pilbara. Credit: CSIRO

One gigalitre is the equivalent of Subiaco Oval, a stadium in Western Australia, filled to the brim. This figure is expected to double by 2042.

“Mine sites are often separate enough from each other not to interact… however current mining and new mines are increasingly below the water table requiring very large volumes to be extracted and there are several areas where multiple mines are interacting with each other,” Dr McFarlane says.

The Pilbara is a land of extremes, suffering through some of the hottest temperatures in the country, while its unpredictable rainfall comes mostly from summer thunderstorms and cyclones.

“It [the study] puts streamflow and recharge volumes into relative perspective,” he says.

“Nine aquifer types were identified and they interact in complex ways with each other and especially with streamflow.”

Beneath the surface
The pipeline that takes water to the West Pilbara Water Supply Scheme. Credit: CSIRO

In addition, the WA Government is investing $40 million to expand irrigated agriculture and enlarge the Pilbara’s grazing industry.

The research, which was funded by industry and government, analysed climate data since 1910, the relationship between rainfall and runoff since 1961 and how that impacts groundwater levels over an area of 300,000 km– an area which is slightly larger than New Zealand.

The researchers say streamflow leaks through riverbeds and is the main source of aquifer replenishment.

According to the three-year study, groundwater-dependent ecosystems expanded and contracted with the weather but the number has remained stable during the past 23 years.

Dr McFarlane says analysis of satellite remote sensing images could play a role in monitoring the future impacts of climate, grazing, fire, feral animals and mining on groundwater-dependent ecosystems and vegetation.

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This article was first published by Science Network Western Australia. Read the original article here.

past Australian environments

Tracing change: past Australian environments

Curtin University researchers are creating snapshots of past Australian environments using the minute traces left behind by plants, animals and microorganisms. Dr Svenja Tulipani and Professor Kliti Grice from the WA-Organic and Isotope Geochemistry Centre looked for clues in sediments at Coorong National Park, South Australia, to find out how this system of coastal lagoons has changed since European settlement.

The Coorong Wetland is an ecologically significant area, but human water management practices and severe drought have led to increased salinity and less biodiversity, Tulipani explains. By examining microscopic molecular fossils, known as biomarkers, and their stable carbon and hydrogen isotopes, the researchers have identified the types of organisms that previously lived in the area, uncovering evidence for changes in water level and salinity due to changes in carbon and hydrogeological cycles.

“We found significant changes that started in the 1950s, at the same time that water management was intensified,” Tulipani says. “It affects the whole food web, including the birdlife and ecology,” Grice adds.


“We found significant changes that started in the 1950s, which was the same time that the water management was intensified.”


The project used Curtin’s world-class instruments for gas chromatography-mass spectrometry, as well as a new instrument that is capable of even better analysis.

“It allows for a new technique that reduces sample preparation time as the organic compounds can be analysed in more complex mixtures, such as whole oils or extracts of sediments and modern organisms,” Tulipani explains. “We can also identify more compounds this way.”

Tulipani has been able to use samples taken from the remote Kimberley region to examine an extinction event around 380 million years ago. Grice says the techniques are particularly relevant to the evolution of primitive vascular plants during this time period.

“In some locations of the Pilbara region, you can look at very early life from more than 2.5 billion years ago. You can go back practically to the beginning of life.”

Michelle Wheeler