Nexus of Food-Energy- Water Challenges Resource Management

The challenges of climate change, population growth, and water scarcity have highlighted the need to develop a better understanding of the interactions among food, energy, and water (FEW) systems. There is a FEW nexus in which energy, water and agriculture are intertwined aspects of resource security. Food production through the agricultural industry is critical for food security and depends on inputs of water and energy. Energy is required to supply and treat water for agriculture, municipal, and industrial uses, whereas water is used for human and industrial consumption, crop irrigation, and energy production. Thus, constraints in one area can significantly impact the others. 
 
In the past, each component of the FEW system has been managed and regulated independently, disregarding the existing linkages among these resources. The increasing demand for fresh water, energy, and food under the pressures of climate change and population growth have increased 
the need for integrated management that accounts for the complexity and dynamic interrelationships of the FEW nexus. Such an approach aims for cross-sector coordination instead of sector specific optima to avoid unintended side-effects and negative sectoral trade-offs.
 
Arizona’s current water use varies between seven and eight million-acre feet per year. Agriculture is by far the largest user of water in Arizona, accounting for about 70 percent of withdrawals. Arizona’s climate allows year-round agricultural production, self-supplying most of its demand for animal feed, livestock, and other food products and also supplying major regional cities, including Los Angeles, San Diego, El Paso, and Las Vegas. 
 
A study conducted by researchers of the School of Sustainable Engineering and the Built Environment at Arizona State University found that irrigation requirements, crop yield, and energy use are sensitive to temperature change. Thus, the entire FEW system is vulnerable to a warming climate. Farmers with low profit margins and crops that use the most water, like alfalfa and cotton, may be more affected by these changes. Farmers could cope with the impacts of climate change without significant investments by changing their crop choices, planting dates, and irrigation timing. A larger investment is required for technological adaptations, which will be important to improvements of energy and water efficiencies. The United States Department of Agriculture in its 2013 Farm and Irrigation Survey reported that only 471 Arizona farms use drip, trickle, and low flow micro sprinklers, while 1,640 farms use traditional sprinkler systems and 3,005 use gravity systems. These numbers show that there is still room for improvement in water efficiency through increased use of more efficient irrigation techniques. 
 
The FEW nexus is emerging as a topic of interdisciplinary research. In this regard, the National Science Foundation (NSF) has awarded several projects aiming to develop a better understanding of the FEW nexus. Researchers at Northern Arizona University have received funding from NSF to create the first detailed mapping of the FEW system of the United States. This project aims to integrate the multiple components of the FEW system, such as regional trade, river basins and aquifers, irrigation districts, crop belts, states, tribes, counties and cities, power grids, and climate gradients, to produce a more comprehensive understanding of their dynamics and interactions. 
A multidisciplinary group of researchers at Arizona State University is working on a project to engage stakeholders in the Phoenix Active Management Area to develop a bottom-up model of the FEW nexus. They are utilizing modeling tools for each component of the FEW nexus and developing a tool, called a knowledge interchange broker, to enable the models to talk to each other. The aim is to create a FEW model for stakeholder and policy engagement.
 
Understanding how the FEW system works as a whole would provide a foundation for future water and energy savings and would help policy and decision makers allocate and prioritize resources in an integrated manner across the food, energy, and water sectors.