Urban metabolism refers to the flows of energy, materials, water, and waste that circulate within the city, enabling its functioning. This approach understands the city as a dynamic system similar to a living organism, facilitating the analysis of its efficiency, sustainability, and relationship with the natural environment.
Kennedy, C., Cuddihy, J., & Engel-Yan, J. (2007). The changing metabolism of cities. Journal of Industrial Ecology, 11(2), 43–59.