Diagnosis for the measurement of the circular urban metabolism in the informal city of Latin America and the Caribbean. Three case studies in Lima.

Cities in the 21st century will concentrate almost 70% of the population. The ecological vision of the city implies a systemic vision of the urban phenomenon (city as an organism). The study of the metabolism of cities focuses on analyzing the various flows (energy, materials, water or information) that the city exchanges with its surroundings. The study of these flows provides relevant information for planning cities, since it performs a detailed follow-up for each flow, identifying impacts at the beginning and at the end of use. However, the study of urban metabolism is a relatively new phenomenon and has been little explored in informal contexts despite representing a central aspect to achieve sustainable cities, especially in Latin America and the Caribbean, where economic resources are usually scarce but community dynamics proliferate, and can contribute to circular flows that generate social, economic and environmental benefits.

The urban metabolism of the informal city in the countries of Latin America and the Caribbean has been little studied and the methods of analysis and study variables are generated in developed countries. In addition, there are various methods to measure urban metabolism in cities and it is not known which of these are applicable to the informal city context, which usually has limited information. It is unknown what aspects should be evaluated within the vision of urban metabolism of the informal city and what public data is relevant for the evaluation of circularity in the informal city. In the case of Peru, the existing data is dispersed in various organizations, and the evaluation is very difficult to carry out. On the other hand, the informal city has limited resources where a linear operating model predominates and resource flows are not used optimally, but in parallel, it presents urban dynamics and community networks with a potential that must be considered for the generation of economic resources based on existing flows. Finally, current public policies and the development of the informal city do not contemplate circularity indicators. An analysis of the flows of energy, water, food supply, power generation and waste management could be incorporated for better planning.