Sam Buchanan tests the waters

Sam Buchanan is not an archetypal desk-bound PhD swot. Asked to outline research methodology for his PhD - "Hydrological Modelling in the Bourke Irrigation District" - he launches into a vivid description of swimming out into the middle of the Darling River to collect riverbed core soil samples in plastic tubes.

He would normally head out to Bourke about three times a year to collect samples, but if we get rain, he'll be out there straight away for weeks on end.

Thanks to a $24,000-a-year scholarship from the Australian Cotton Cooperative Research Centre, as well as money for research trips from the Australian Cotton industry, Sam is able to spend the next three years working full time on his PhD. He will use the time to try to develop a detailed understanding of groundwater movement under the influence of irrigated agriculture and to simulate how this influences river and aquifer dynamics.

In short, he wants to see if he can better understand whether water used to irrigate crops that has sunk into the soil - becoming groundwater - then moves into the Darling River, carrying salt and other additives with it. The subsurface of the Bourke area is extremely salty, and groundwater found there is about 85 per cent as salty as seawater, whereas the water in the Darling River is comparatively fresh.

He is looking at developing a model that measures salinity concentration in groundwater and tracks its movement.

His fascination with salinity issues comes from spending part of his childhood on his grandfather's farm on the Darling Downs. His uncle also farmed cotton at Emerald in Queensland.

For his undergraduate degree, Sam studied environmental science in our Department of Geography, and looked at salinity on golf courses in his honours year.

He eventually hopes to establish an international private consultancy business specialising in hydrology.