Quantifying the Urban Food–Energy–Water Nexus: The Case of the Detroit Metropolitan Area

The efficient provision
of food, energy, and water (FEW) resources
to cities is challenging around the world. Because of the complex
interdependence of urban FEW systems, changing components of one system
may lead to ripple effects on other systems. However, the inputs,
intersectoral flows, stocks, and outputs of these FEW resources from
the perspective of an integrated urban FEW system have not been synthetically
characterized. Therefore, a standardized and specific accounting method
to describe this system is needed to sustainably manage these FEW
resources. Using the Detroit Metropolitan Area (DMA) as a case, this
study developed such an accounting method by using material and energy
flow analysis to quantify this urban FEW nexus. Our results help identify
key processes for improving FEW resource efficiencies of the DMA.
These include (1) optimizing the dietary habits of households to improve
phosphorus use efficiency, (2) improving effluent-disposal standards
for nitrogen removal to reduce nitrogen emission levels, (3) promoting
adequate fertilization, and (4) enhancing the maintenance of wastewater
collection pipelines. With respect to water use, better efficiency
of thermoelectric power plants can help reduce water withdrawals.
The method used in this study lays the ground for future urban FEW
analyses and modeling.