Author(s): Luis Izquierdo Horna, Ramzy Kahhat Abedrabbo, Ian Vázquez Rowe
(Español) Municipal solid waste (MSW) generation forecasting has become an important tool for decision-making in urban environments, not only due to its essential role in effective waste management, but also because it provides an understanding of the complexity of the factors that govern it. Current research bases its forecast models (e.g., artificial neural networks, regression methods, three decision methods…) on predictive variables supported by pre-existing government information or, alternatively, on related studies with different site characteristics due to the lack of primary data from the specific sector. These assumptions and generalizations generate a different representation of the area of interest, raising the level of uncertainty of the results and reducing their level of reliability. The current review focuses on exploring the influence, relevance and opportunities for improvement when it comes to including or excluding sociocultural, environmental and/or economic variables in the solid waste forecasting process. Relevant information has been provided regarding the predictor variables considered to have better predictive power and, at the same time, limitations in data availability have been highlighted. Finally, it is concluded that the adoption of case study-specific predictor variables collected through primary data (e.g., questionnaires or surveys) would improve the predictive performance of the models providing a robust and effective tool for waste management. In addition, it is expected that the recommendations provided will be useful for future research related to MSW prediction and, thus, contribute to obtaining more representative results.
Open linkAuthor(s): (Español) Jorge Cristóbal, Ian Vázquez-Rowe, María Margallo, Diana Ita-Nagy, Kurt Ziegler-Rodriguez, Jara Laso, Israel Ruiz-Sálmon, Ramzy Kahhat, Rubén Áldaco
(Español) Waste management is a critical policy towards the reduction of environmental impacts to air, soil and water. Many Latin American countries, however, lack a correct waste management system in many cities and rural areas, leading to the accumulation of unmanaged waste in illegal or unregulated dumpsites. The case of Peru is of interest, as it hosts 5 of the 50 largest dumpsites in the world. An erratic waste management compromises climate actions for Peru to commit with the Paris Agreement, as no correct closure systems are established for these dumpsites. Therefore, the main objective of this study is to assess the contribution of the past and present biodegradable waste produced and disposed of in the most critical open dumpsters to the overall annual greenhouse gas (GHG) emissions of Peru using the IPCC model. Thereafter, the climate change mitigation potential of possible dumpsite closure strategies based on a selection of technologies, including economic feasibility, were estimated. Results show that cumulative GHG emissions in 2018 for the 24 crit- ical dumpsites evaluated added up to 704 kt CO2 eq. and a cumulative value of 4.4 Mt CO2 eq. in the period 2019–2028, representing over 40 % of solid waste emissions expected by 2030. Mitigation potentials for these emissions tanged from 91 to 970 kt CO2 eq. in the ten-year period depending on the mitigation strategies adopted. The costs of these strategies are also discussed and are expected to be of utility to complement Peru's waste management commitments in the frame of the Paris Agreement.
Download publication (1.43 MB)Author(s): Red Peruana Ciclo de Vida
Open linkAuthor(s): (Español) Alejandro Parodi, Gianfranco Villamonte-Cuneo, Ana Maria Loboguerrero, Deissy Martínez-Barón, Ian Vázquez-Rowe
(Español) Peru is promoting the adoption of agroforestry systems with the aim to halt the deforestation of tropical forests caused by smallholder farmers. However, deficient soil conservation practices and nutrient management are common among the targeted smallholders, hampering the success of this strategy. In this study, we explore the potential of valorizing municipal biowaste as compost to be used as soil amendment in coffee agroforestry systems and in silvopastoral systems. The analysis was concentrated in four Peruvian regions and the most populous city in each of them. For lands with coffee production, it was assumed that 90 kg N ha−1 (i.e., 50% of the N requirements) should come from compost, while for pastures, the requirement was 40 kg P ha−1. We found that composting could lead to large greenhouse gas (GHG) reductions compared with the current waste disposal methods (i.e., deep dumping and landfilling), as it only emits 5–10% of the GHG emissions produced with the other methods. Nonetheless, the area of agroforestry and silvopastoral systems that could be fertilized with compost obtained from the main city of each region is limited and insufficient. If all compost were to be used for the coffee agroforestry system, less than 3% of the coffee agroforestry area could be fertilized, while in the case of pastures, only 4% would be attained. Large amounts of compost could be obtained from Lima, the most populated city; however, its transportation to the agroforestry areas would increase compost GHG emissions by 15–60%. Although composting municipal food waste and loss may bring GHG benefits and should be promoted, its use as a fertilizer requires mixing with N-rich sources to improve its nutrient quality.
Download publication (1.46 MB)Author(s): Úrsula Cárdenas Mamani, Ramzy Kahhat Abedrabbo y (Español) Jose Manuel Magallanes
(Español) Critical infrastructures (CIs) are key for the functionality of urban areas. Their failure due to natural disasters or manmade disruptive events could severely obstruct normal city activities, producing considerable social and economic impacts. Understanding CI performance and interdependence during these events is imperative. This study aims to comprehend the independent and interdependent response of three CIs in a South American megacity: Lima, Peru. Topological indicators were used to study three CIs: potable water distribution, electricity distribution and natural gas distribution; five disruption scenarios were modeled. Results show that, compared to the other CIs, the potable water system has the highest redundancy, while the electricity network has the best capacity to connect among all elements. The structure of the natural gas system makes it fragile and susceptible to failures, generating the lowest values across indicators. Regarding the interdependence analysis, certain elements (e.g., medium- and high-voltage substations, water treatment plant, pressure stations) with a high degree of connectivity influence the entire performance of the systems; the interdependent effect exposes some CIs to damage more than others. Earthquakes have a comparatively more negative impact on the CIs studied than manmade disruptive events. In order to reduce vulnerability factors in the three systems, an important mitigation action would be to reduce the centralization of the systems.
Open linkAuthor(s): (Español) Jara Lasso, Jorge Cristóbal, María Margallo, Rubén Aldaco, Ian Vázquez-Rowe
(Español) The combination of life cycle assessment (LCA) and data envelopment analysis (DEA) methodologies has been employed over the past years to assess the eco-efficiency of a wide spectrum of production systems. This chapter presents a critical review on current practices of the joint application of LCA + DEA, as well as point towards the methodological challenges and opportunities for the future. Considering the growth of the method in the past decade, it is plausible to assume that an increasing number of studies will continue to appear in the literature. The development of guidance or standardisation reports would constitute a step forward in terms of providing advice on how recurrent methodological issues (e.g. uncertainty, selection of impacts categories or DEA models, etc.) should be addressed in LCA + DEA.
Open linkAuthor(s): Matías Gutiérrez Medina, Ramzy Kahhat Abedrabbo
(Español) Urban areas accumulate important quantities of secondary resources that in the future could be part of what are called “Urban mines”. While this stock is growing as population in urban areas increases, different types of constraints could limit its growth, especially with regard to the building stock. Applying the concepts and methods of material stock analysis, this research proposes an approach that helps assess the limits to the growth of building stocks in areas with horizontal growth constraints. These limits are studied on the basis of established zoning, urban and building parameters, and are quantified for two neighboring districts in Metropolitan Lima, whose central location amid multiple districts limits their horizontal growth possibilities. Three scenarios are used to explore the limits, which determined that the ratio of current material stock to the theoretical maximum allowed, ranged between 26-30% and 41–50%. Results show that zoning is a limiting factor for the upward growth of cities, and that while generally there is potential to grow, some areas are closer to their limits than others. Though municipal zoning considerations may change in the future, increasing or decreasing the limit, the study provides an important approach for understanding the limits to the growth of urban stocks.
Open linkAuthor(s): Ramzy Kahhat Abedrabbo, Marco Gusukuma Higa y (Español) T.Reed Miller, Sara Ojeda-Benitez, Samantha E. Cruz-Sotelo, Jorge Jauregui-Sesma.
(Español) Mexicali, a Mexican city located near the US-Mexico border, has faced several challenges related to adopting an integrated e-waste management system. Thus, the main objective of this work is to propose a new system to be implemented in phases. The current system is evaluated using several methodological approaches including field studies, surveys, interviews, and quantitative modeling via material flow analysis. We suggest the need to properly integrate both the formal and informal sectors to achieve the optimal system that mitigates environmental impacts while preserving the positive social and economic traits of the current system. Thus, without supplanting the current reuse, refurbishment, repair and maintenance practices, a hybrid system is proposed, based on a centralized facility that primarily handles those parts or materials that create environmental impacts and health hazards if mishandled. Furthermore, a decentralized transition phase toward the new system is recommended.
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