What's in the dirt?

23 September 2003

Information from a pilot geochemical survey in the eastern Riverina region will ultimately help develop strategies to expand the survey to the whole of the Murray-Darling Basin, and perhaps even beyond.

Scientists will be collecting sediment and groundwater samples in the larger catchments of the eastern Riverina region from mid September to early November 2003.

"Many countries have used low-density geochemical surveys, such as this one, to obtain vital information about the composition and health of the landscape on which we live and from which we extract our food and water," said Dr Patrice de Caritat from Geoscience Australia.

The first phase of this project, driven by Geoscience Australia and the Cooperative Research Centre for Landscape Environments and Mineral Exploration (CRC LEME), will involve visiting about 80 sampling sites in the eastern half of the Riverina bioregion. At each site, a sample of the top 10 cm and a deeper sample from 80-90 cm depth will be collected.

"We will analyse the inorganic compounds found in the sediments by looking at the composition of minerals that make up the sands, silts and clays at each of these sampling sites. The results will help farmers and land managers decide how best to use the land."

"Our team will work closely with the local Riverina community to get the best information required for the survey," added Dr de Caritat. "We have presented the project to all the Shire Councils and made contact with landholders to request specific permission to access their property to collect the samples."

The sites will be in areas of floodplain deposits of creek and river systems to obtain samples that will best represent the catchment.

This pilot study is the first in a larger project which aims to survey the entire Murray-Darling Basin, Australia's most important region of agricultural production, where just under half the nation's farms produce 34% of our wheat and 96% of our cotton.

"The second stage of the study will be carried out in October this year when we return to the Riverina to take groundwater samples from pumping stock bores near the sites where we are now taking soil samples," said Dr de Caritat.

"We hope to carry out a similar survey in the western half of the Riverina region in 2004. Ultimately, information from the survey will be accessible to governments and stakeholders to assist them with decisions about land-use management, geohealth and resource development."

Topic contact: media@ga.gov.au Last updated: October 4, 2013