Five things we’ve learnt about water in the Pilbara

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Home to some of the most stunning Australian landscapes, the Pilbara region and its inhabitants can only survive this extreme environment by understanding the scarce water supply.

Last week the world watched on as NASA announced the discovery of flowing water on Mars. This week we’re analysing water on a patch of red dirt a little closer to home.

The Pilbara – a 500,000 square kilometre stretch of land that’s home to 50,000 people in northern Western Australia. It’s hot, dusty… and full of minerals. The region’s high-grade iron ore deposits, significant deposits of gold, manganese, copper and uranium, not to mention the offshore gas reserves, make it one of the world’s most important resource regions.

It’s also a region that is rich in environmental and cultural values, and has significant areas of grazing land. Whether it’s the vast reserves of iron ore, the spectacular diversity of plants and animals, or some of the oldest living Indigenous cultures in the world, there’s one resource they all depend on — water.

Front-Hamesley Ranges

The Hamersley Range stretches across the Pilbara region and includes some of the world’s oldest rock formations.

That’s why we joined forces with the Government of Western Australia and BHP Billiton to conduct the biggest study into the water resources of the Pilbara, ever – it even has a catchy name: the Pilbara Water Resource Assessment.

It took three years and dozens of researchers, but we now have a body of knowledge that will help guide water planning and management for the Pilbara into the future.

Here are some of the interesting things we’ve learnt:

1. Ten times more water can evaporate in the Pilbara than falls as rain

Because of the blistering extreme heat in the Pilbara, surface water doesn’t last long. The Assessment found that the potential evaporation exceeds annual rainfall by 6 to 14 times, depending on the location within the Pilbara. Despite this, fresh water sources are quite common throughout the region.

2. Groundwater is the most important water source

This is a bit of a no brainer when you consider the first point. Groundwater is currently the main water resource used by towns and industry. This groundwater is not only vital to communities, but it also supports a range of ecosystems, usually near river pools and springs. These ecosystem include species of Acacia found nowhere else, one of the richest assemblages of reptiles in the world, and some of Australia’s iconic mammals – such as the northern quoll and greater bilby.

The greatest variety of ecosystems which depend on groundwater were found in the Hamersley Range.

Ecosystems are supported where groundwater is discharged to river pools and springs

It might be picturesque, but for the ecosystems of the Pilbara the groundwater discharged by these river pools and springs is absolutely vital for survival.

3. We know what it takes to make a stream flow

Between 8 and 30 mm of rain is required for runoff to occur in most Pilbara catchments, which makes the streams and rivers flow. This is important because runoff is the main way the region’s aquifers will be recharged with water. The runoff leaks through streambeds into shallow aquifers just under the surface and from there is able to replenish deeper aquifers, which can store large quantities of water within inland areas.

4. The Pilbara is almost certainly getting hotter

Despite the uncertainty inherent in predicting future climate, there’s one thing that all the Global Climate Models used in this study agree on – the Pilbara is getting hotter. The assessment team used the same modelling tools used by the Intergovernmental Panel on Climate Change to determine what the future climate might look like in the Pilbara. The models project temperatures will be about 1°C warmer by 2030 and 2°C warmer by 2050, compared with 1980s temperatures.

5. It is getting dryer… and wetter

The team assessed the rainfall trends for the area and found that between 1961 and 2012 the east of the Pilbara had become wetter and the west of the area had become drier. They also used the climate models to predict future rainfall for the Pilbara and the models were split on whether the future would be warmer and drier, or warmer and wetter.

Rainfall in the Pilbara results from both tropical weather processes from the north and temperate weather processes from the south. This makes it difficult to predict future rainfall trends for the region because the modelling suggests these processes will respond differently to any increases in greenhouse gases into the future.

On balance, the climate projections carried out by the Assessment team indicate the Pilbara may become slightly drier by 2030 and 2050. But they’re not ruling out the potential for a wetter future either — they modelled a range of wet and dry future scenarios so water managers can be prepared.

If this makes you thirsty for more information about the Pilbara’s water check out the Assessment’s final reports. You can also enjoy a selection of images from this stunning region in the gallery below.

The Pilbara Water Resource Assessment was funded by CSIRO, the Government of Western Australia and BHP Billiton. The project was led by CSIRO and overseen by officers from the Department of Water, BHP Billiton, the Pilbara Development Commission and the Water Corporation.

Media contact:

Chris McKay | +61 7 3833 5728 | +61 455 085 247 | chris.mckay@csiro.au


Shale gas, coal seam gas… what’s the difference?

By Tsuey Cham

A few weeks ago we took a look at coal seam gas (CSG) and the hydraulic fracturing (‘fraccing’) process used in its extraction. You may have also heard of shale gas, another type of natural gas found deep underground.

So what exactly makes them different?

In terms of their gas content they’re really quite similar, with both made up predominantly of methane – the type of gas used in homes for cooking and heating.

However, when it comes to extraction and production CSG and shale gas can be quite different. For example, CSG can be found up to about 1000 meters underground, whereas shale gas is found much deeper, usually 1500 to 4000 meters below the surface.

In Australia, hydraulic fracturing – a technique that increases the rate of gas flow for extraction – is used in CSG production 20-40% of the time, whereas in shale gas production it’s used every time.

Another interesting difference is that the process used to extract CSG produces more water than it uses – so there are large quantities of water produced as a by-product. Conversely, for shale gas, the extraction process uses more water than it produces.

Watch our latest short animation to find out more about shale gas, how it’s extracted and some of the potential environmental challenges involved in its production:

If you missed the animation on CSG extraction, watch it here.

You can also find out more from our fact sheets on CSG, shale gas and hydraulic fracturing in coal seams.


The future of biodiversity is in our hands

Australia’s Biodiversity series – Part 12: Conclusions

When talking about the fate of biodiversity it’s easy to get bogged down in doom and gloom—we know that it’s in decline, that human populations and demand for resources continue to grow, and therefore the pressure we’re putting on other species is increasing, and that big gaps remain in our understanding of the biodiversity that’s out there.

Australia is developing a vast capacity for monitoring the natural environment through the Terrestrial Ecosystem Research Network. Image: Gregory Heath.

Australia is developing a vast capacity for monitoring the natural environment through the Terrestrial Ecosystem Research Network. Image: Gregory Heath.

But there are solutions. Since the concept of biodiversity first emerged in the 1980s, the science dedicated to understanding our natural systems has come a long way. With the emergence of new technologies it has become possible to find out far more about the species we share the planet with, and we can do it with far more efficiency.

It’s these big challenges and scientific solutions that we focused on in our book, Biodiversity: Science and Solutions for Australia. In the twelfth and final video in our Australia’s Biodiversity series, the book’s editors, Dr Steve Morton, Dr Mark Lonsdale and Dr Andy Sheppard, engage in a panel discussion about the future of biodiversity science in Australia:

You might like to read the concluding chapter of CSIRO’s Biodiversity Book to find out more about the scientific solutions that could help us address the big threats to Australia’s biodiversity.

And if you’ve been inspired to get more involved in the management of our biodiversity, there’s a lot you can do—even from your computer. Visit the Atlas of Living Australia to find out about volunteer opportunities.

You can find all the videos from our biodiversity series on our YouTube channel.


Mining and biodiversity: are they getting along?

Australia’s Biodiversity series – Part 11: Mining

Dolphin poking its head out of the water in the foreground and a ship in the background

Dolphin conservation is carried out to offset impacts of infrastructure development in Darwin Harbour. Image: Carol Palmer

Many people worry about the environmental impacts of mining, but as a society we have a growing demand for its products. Most Australian’s consider it worthwhile and a valuable industry for the nation’s prosperity, as our recent national survey indicates.

The direct impacts of mining on biodiversity are relatively limited compared with other major land uses—less than 1% of the Australian land area is used for mining, while 62%  is used for agriculture for example.

The greatest threats to biodiversity from mining come from the cumulative impacts of the infrastructure required for mining operations—roads, ports, pipelines, shipping etc. Science can help to assess any potential implications for biodiversity from mining development so that impacts can be better managed and rehabilitation and offsetting efforts can be more effective.

In the eleventh video of our Australia’s Biodiversity series, Dr Alan Andersen talks about the main impacts of mining on biodiversity and how these can be appropriately managed through processes like strategic regional assessments, use of bioindicators in rehabilitation, and biodiversity offsets:

To find out more about mining and biodiversity in Australia, you might like to read the corresponding chapter of CSIRO’s Biodiversity Book.

Last week’s video looked at the biodiversity in our inland water systems and how our approach to water management impacts ecosystem health. You can review it and the other videos in the series on our YouTube channel.


Water: we need it to live, and so does our wildlife

Australia’s Biodiversity series – Part 10: Inland waters

Even though it is one of the world’s most arid continents, Australia’s inland waters support a rich diversity of life.

Rivers, streams, wetlands, floodplains, lakes, underground aquifers—we’ve got them all and they all support native species.

A large brown and yellow frog

The New Holland water-holding frog. 94% of our frog species are found only in certain ecosystems – the highest rate of endemism among Australia’s vertebrate species. Image: Danial Stratford.

Biodiversity is enhanced by the wide variation in rainfall across the continent and the change in climate from the tropical north to the temperate southern regions. Life in Australia’s inland water ecosystems has had to adapt to the ‘boom and bust’ that comes from periods of both extreme dry and extreme wet.

Human development has had a dramatic impact on these ecosystems, particularly in the Murray Darling Basin and other areas in the southeast, as we use water for our cities and towns and for irrigated agriculture. These water uses are obviously of great benefit to the Australian population but the use of the water and the infrastructure associated with it can disrupt the natural flows of water and nutrients through inland water ecosystems, which native plants and animals depend on.

In the tenth video of our Australia’s Biodiversity series, Dr Carmel Pollino talks about Australia’s unique inland water ecosystems and how water can best be managed for the benefit of biodiversity and our communities:

To find out more about the biodiversity in our inland water ecosystems, you might like to read the corresponding chapter of CSIRO’s Biodiversity Book.

Last week’s video looked at the new ways science is attempting to understand the unknown biodiversity in our oceans. You can review it and the other videos in the series on our YouTube channel.


A sea full of mysteries to be solved

Australia’s Biodiversity series – Part 9: Seas and coasts

Life originated in the oceans 3–5 billion years ago and even today 20 of the 33 animal phyla (the highest groupings within the animal kingdom) remain confined to the sea. That means that most life under the sea is like nothing we find on land.

An elephant seal with an electronic tag on its head

Sea creatures can also help us explore the oceans. Sea mammals can take sensors to parts of the ocean we’d never be able to go ourselves, like under Antarctic sea ice. Image: Chris Oosthuizen

Worldwide there are big gaps in our understanding of the oceans and the life within them. Our exploration of Australia’s marine biodiversity has been limited mostly to the margins of the continent, on the continental shelf and the upper continental slope. Even near the continent, some 50–70% of the species we’ve found in recent surveys have never before been seen by scientists.

New technology and equipment, like autonomous robotic vehicles and electronic tagging, as well as our brand new marine research vessel, RV Investigator, is allowing us to explore in ways we’ve never explored before and so we can begin to address those knowledge gaps.

In the ninth video of our Australia’s Biodiversity series, Dr Alan Butler and Dr Nic Bax talk about the unique habitats of the sea, the challenges it poses to exploration, and new tools and technologies helping us discover and manage the biodiversity it holds:

To find out more about discovering biodiversity in the ocean, you might like to read the corresponding chapter of CSIRO’s Biodiversity Book.

Last week’s video looked at the relationship between our cities and biodiversity. You can review it and the other videos in the series on our YouTube channel.


Can cities cater for our critters too?

Australia’s Biodiversity series – Part 8: Cities and towns

Cities are one of the great inventions of civilisation. They are centres of knowledge, invention and cultural change. But how good are they at supporting the local plants and animals?

Cities tend to have been built in areas of high biodiversity, with rich soil and permanent water supplies, and so there may be more species living in and around your city or town than you think. Simply punching your postcode into the Atlas of Living Australia will give you a list of everything that’s been recorded there.

Of course, the fact that there’s now a city on that land will have impacted species’ ability to persist there. The way we design and lay our cities out has an influence on how extensive that impact is, and will continue to be important as cities and populations grow.

Views of Canberra and New York City cityscapes

Canberra and New York City are at opposite ends of the urban density spectrum. But which is better for biodiversity? Image: Mark Lonsdale

Cities occupy just 2% of Earth’s surface but account for 75% of the resources consumed by humans. That sort of resource use represents one of the biggest challenges to the world’s biodiversity. But being centres of cultural change, cities also present many opportunities to engage people in supporting biodiversity conservation efforts.

In the eighth video of our Australia’s Biodiversity series, Dr Mark Lonsdale talks about the relationship between cities and biodiversity and some of the big ways cities can play a role in supporting our biodiversity in coming decades:

To find out more about the relationship between our cities and towns and biodiversity, you might like to read the corresponding chapter of CSIRO’s Biodiversity Book.

Last week’s video looked at agricultural landscapes and how they can be better managed to support biodiversity. You can review it and the other videos in the series on our YouTube channel.