UNSW global water institute irrigation (4)

In profile: Valeria Almeida Lima, PhD Candidate

Growing up in Brazil’s semiarid region, drought was a constant presence in Valeria Almeida Lima’s life. Being exposed to the devastating impacts of drought on communities meant that Valeria was always fascinated by water and how the essential resource is managed.  

Valeria with bean plants fed by membrane-based irrigation system

During her degree in Agricultural and Environmental Engineering at Brazil’s Federal University of the Semiarid Region, Valeria focused on wastewater recycling for irrigation, and her interest in agriculture continued as she began her PhD at UNSW’s UNESCO Centre for Membrane Science and Technology.

In agriculture, it is well known that the use of irrigation water with a high concentration of salts and of total dissolved solids can degrade both plant growth and soil quality. However, high-quality freshwater is not always accessible, and this issue will only escalate as time goes on.

“The world faces an unbalanced scenario of increased population growth and food production with limited water quality,” said Valeria.

“Given this trend of increased demand, which for some localities exceeds the availability, the agricultural sector has been forced to consider using additional sources of water which are lower in quality, such as brackish water or wastewater.”

While conventional desalination processes can effectively remove salts from brackish water, these processes are both complex and costly, making them out of reach for many communities. Furthermore, they are usually unsuitable for irrigation at a larger scale.

Through her research, Valeria is currently investigating the use of semi-permeable membranes to form a subsurface irrigation system, which would desalinate water before it reaches crops.

Not only would this approach allow brackish water to be utilised for irrigation, it would also contribute to efforts to improve precision of irrigation and improve water usage efficiency. 

“In the subsurface irrigation system, semi-permeable membranes are used to form irrigation pipes from which water can be consumed naturally by soil and plant roots, according to their changing water needs. This means that plants will only consume the required amount of water when they need it, eliminating water loss caused by inaccurate estimations of crop water requirements,” said Valeria.

Valeria’s ground-breaking research is being supervised by Associate Professor Pierre Le Clech and Professor Greg Leslie, and she credits the ongoing support extended to her throughout the PhD process.

I have always felt supported by my supervisors to achieve professional excellence

Valeria Almeida Lima, PhD Candidate

“Out of the many Australian Universities that I sent applications to, UNSW professors were the most helpful with my PhD application. They were prompt to respond to my queries and devoted to finding research that best fit my interests and previous experience.”

“I have always felt supported by my supervisors to achieve professional excellence, and I appreciate the many opportunities provided to expand my network by interacting with other professionals and companies at local and international conferences.”

Following her PhD, which is also supported by the CAPES Foundation (Ministry of Education, Brazil), Valeria hopes to investigate further research on irrigation technologies and ultimately build a career with an agricultural organisation providing technical assistance to farmers.