Urban material flow analysis: An approach for Bogotá, Colombia
The urbanisation process has exceeded the traditional pace of human settlement and is moving towards the formation of large urban regions in response to an increasing demand for services and environmental goods, combined with increasing production of waste and emissions. Therefore, it is fundamental to determine resource flows into cities, especially in developing countries, as well as the transformations that occur and the outputs that are produced, such as products, services and wastes. In this study, we apply urban material flow analysis, which determines the flows of inputs (water, energy, food and others) and outputs (wastewater, air pollution, wastes and others) to the city of Bogotá, Colombia to determine the relationship between demand for resources and the environmental impact of outputs. Quantitative and qualitative data for Bogotá are used to assess and compare the material and energy flow trends for this city. The results indicate that in this city, inputs and outputs are directly and linearly related. Consumption of energy and construction materials has increased, whereas food and water consumption have remained steady. Levels of recycling and sewage treatment are low, and emissions such as particulate matter have decreased. The findings from this study can be used to formulate and apply policies and strategies to improve the sustainability of resources, decrease the reliance on physical resources, increase the efficiency of resource and energy use in urban areas, and enhance sustainable production and consumption in cities.