Farmer study provides water use lessons

Photo / File

Research into Vietnamese farmers' groundwater usage could have benefits for their Australian counterparts, according to a study from Flinders University.

The heavily agricultural La Vi River Basin in Vietnam was the focus of the study, forming part of a five-year project funded by the Australian Centre for International Agricultural Research (ACIAR).

"Groundwater use for food and industrial production is increasing globally, putting pressure on groundwater resources and associated ecosystems," said Flinders University Professor Okke Batelaan.

"In many countries, particularly in developing regions as well as Australia's Murray-Darling Basin (MDB), this abstraction may be poorly organised and not regularly gauged for data."

Over-allocation of surface water for growing food crops is shifting agriculture and other industry to use groundwater - which was much more difficult to measure and monitor.

Using local farmer knowledge as "soft data" to estimate groundwater use in modelling was a helpful tool in mapping sustainable use of scarce resources, Flinders University experts said.

Environmental and water researchers from Flinders have described the technique in a new paper published online in the Journal of Hydrology: Regional Studies.

Vietnamese farmers are shifting to more water efficient watering methods as groundwater supplies run short. Photo / Dr Margaret Shanafield, Flinders University

The researchers, including John Allwright fellow Flinders PhD candidate Manh Hai Vu, interviewed local farmers about their land use, agricultural practices and water use.

The approach was very helpful in collecting base line information for future use – particularly when climate change or variable rainfall posed a threat to future water management, said Dr Margaret Shanafield, from the National Centre for Groundwater Research and Training based at Flinders University.

"Although often thought of as a wet, tropical climate, Vietnam's South central coast has long dry seasons, and hence suffers from surface water shortages, similar to many parts of Australia," said Shanafield.

The heavily agricultural La Vi River Basin in Vietnam was the focus of the ACIAR study. Photo / Flinders University

"Groundwater use provides a significant solution to local farmers for producing cash crops and improving livelihood."

The system could also be used in Australia in areas such as the northern part of the MDB where groundwater is largely unmonitored.

The study developed a cost-effective and computationally simple solutions for estimating groundwater abstraction in data-poor agricultural regions, researchers said.

- Mapping catchment-scale unmonitored groundwater abstractions: Approaches based on soft data (2020) by Vu MH Vu, M Shanafield, TT Nhat, D Partington, O Batelaan has been published in the Journal of Hydrology: Regional Studies