Unravelling the role of groundwater in the Water-Energy-Food NEXUS

Human societies and the whole planet are facing a number of challenges, due to climate and global changes, including freshwater scarcity and increase in demand for food and energy. Groundwater is a valuable resource supporting life, ecosystems, agriculture, and in general several human activities. Compared to surface water, groundwater has a longer temporal buffer, wider spatial distribution and more reliable water quality, making it a major source of freshwater in many areas of the world.

The concept of Water-Energy-Food (WEF) Nexus has been proposed to highlight the complex interactions between water, agricultural production and energy, in order to ensure an integrated planning and management for these main assets. In such a context, groundwater plays a key role in the WEF Nexus, but the interdependencies with the agricultural and the energy sectors and their synergistic impacts have been rarely evaluated.

This work aims at addressing this issue by means of a systematic review searching the Scopus database for scientific articles published up to December 2023. Our search resulted in a total of 392 papers, and after analyzing all of them, we identified 217 papers suitable for our current research objectives, and an additional 3 papers were included by snowballing.

Groundwater is the main source for irrigation in many parts of the world. Inefficient irrigation may be one cause of aquifer overexploitation, while increasing efficiency may be thought of as a way to save groundwater. However, there are several cases where technological improvements in turn, may call for larger irrigated areas, hence creating a loop. At the same time irrigated agriculture increases the use of fertilizers and pesticides, which in turn means larger energy consumption and CO₂ emissions for their production, transportation and distribution. Energy is needed in farming for groundwater pumping, and in some cases routing. Energy may be needed also for treating groundwater to drinking standards. Competition for groundwater may exist between the industrial (including energy production) sectors and the agricultural one. Solutions to reduce groundwater exploitation (i.e. reuse of treated wastewater or desalinated water) may in turn increase energy consumption and decrease environmental quality. Our work provides a matrix to highlight the most relevant interdependencies among the groundwater resource, energy and agricultural production in order to support sustainable planning and development.

 

Acknowledgement

This contribution is presented within the framework of the NEXUS-NESS project. The NEXUS-NESS received funding from the PRIMA Programme, an Art.185 initiative supported and funded under Horizon 2020, the European Union’s Framework Programme for Research and Innovation.