Groundwater technology win for young scientist

Sam Buchanan is the winner of the 2006 young water scientist award for his pioneering research to develop a cheap and effective method that accurately predicts groundwater depth.

Knowledge about the depth of groundwater is important to sustain a healthy ecosystem and maintain high agricultural yields by keeping groundwater out of the crop root-zone, particularly in landscapes susceptible to salinity.

The $2500 award recognises outstanding projects that will be applied to conserve and protect Australia's water resources. Six young Australian water scientists reached the final and presented their research to an international audience of river managers, scientists and policymakers at this year's River Symposium in Brisbane.

"In broad acre dry-land farming, salinity is a huge issue; 5.7 million hectares of land are susceptible. I've been working with cotton farmers to establish the depth of groundwater, as it is one of the main ways salinity moves through the soil," said Buchanan, of the Cotton Catchment Communities Co-operative Research Centre.

"In most parts of New South Wales there is very limited information on groundwater depth, at best there are a few bore readings every 50 km or so. We can now predict accurate depth measurements every 100 metres."

Buchanan took a small number of groundwater depth readings to correlate with other environment parameters, such as elevation and emitted radiation. If a correlation emerged, he used it to model and predict groundwater depth across the rest of the 300 km² study area.

"We wanted to add significant value to data already available and used by farmers while incurring minimum additional cost," said Buchanan.

"People already use the environmental correlation method to predict other environmental properties but no-one had applied it to groundwater depth."

Part of Buchanan's work involved advising farmers where changing irrigation method, from furrow to lateral, would be most effective. Furrow irrigation, although cheaper than the lateral method, increases the amount of seepage through the soil, which in turn can raise groundwater depth. In one season, 374 million litres of water were saved over 150 ha thanks to these changes.

Buchanan is developing software that will allow farmers to apply the method to their own land.