Getting to know our catchments
Ms Perveen with Dr Webb.
La Trobe Geologist John Webb is getting in on the ground level of a new multi-million dollar research centre devoted to managing Australia’s water resources. The enterprising researcher has spent the past decade in Western Victoria using his knowledge of geology to pinpoint sources of groundwater.
That solid foundation in the science of how groundwater systems work has paid off with his participation in the Centre for Groundwater Research and Training. The Centre will be co-funded at $6 million a year for five years by the Australian Research Council and the National Water Commission.
Dr Webb, Associate Professor in Earth Sciences, will run a $250,000 project within the Climate and Landuse Program at La Trobe, in conjunction with the Victorian Department of Primary Industry.
The project aims to provide in-depth answers to many of the questions raised by communities about the impact of farming practices on groundwater levels.
‘Communities in Victoria are concerned about changes in land use, including the negative impact of tree plantations on water resources over the past decade,’ says Dr Webb. ‘For example, we know that trees can use a lot of water but we don’t know if they are depleting groundwater reserves.’
Tax incentives have encouraged blue gum plantations for the pulp industry on otherwise marginal farming land, he says, and a new processing plant is planned near Hamilton.
There may be evidence, however, that the impact of the trees is ambiguous. Preliminary studies show they can drain water back into the groundwater aft er rain. Researchers have tracked run-off down the trunk and roots, but no-one has yet measured the contribution to groundwater reserves.
‘We want to get real data to determine how much aff ect they really have,’ the geologist says.
Dr Webb is supervising PhD student Fahmida Perveen to undertake more detailed research in three small catchments in western Victoria – Crawford River, Dundas Tableland and the Grampians.
Future Farming Systems, a section within the Department of Primary Industry, has recently committed $480,000 to installing bores and weirs to continuously measure groundwater levels and composition in these catchments.
Ms Perveen will measure flow rates at these locations and model the history of reserves by determining the age of the groundwater and recharge patterns.
She has come from Karachi, Pakistan, to do her PhD at La Trobe. The city of 15-20 million depends on groundwater supplies, she says.
‘Many residents have bores in their homes. A family of eight to ten people needs a lot of water,’ she says. Ms Perveen studied the seasonal variation and quality of groundwater in Karachi and found high levels of nitrate.
‘The quality is not good. Groundwater should be an issue in Karachi but it’s not,’ she says. Sewerage lines need to be repaired, but it is not a high priority for the current authorities.
The best thing about doing research here, she says, is the knowledge that her results will be used to ‘give benefit to the common man’.