Multi-criteria site selection for solid waste disposal: Integration of centre of gravity and AHP-GIS analysis in Guayas, Ecuador

Marcela Aguiñaga-Vallejo¹Cecilia Paredes-Verduga²María Jácome-Cornejo¹Josué Briones-Bitar³Maria Jaya Montalvo^3,4,5Fernando Morante-Carballo^3,4,6,7Sebastián Suárez-Zamora⁴Maribel Aguilar^3,4,5Edgar Berrezueta Alvarado⁸Paúl Carrión-Mero^3,4*

• ¹Prefectura Ciudadana del Guayas, Guayaquil, Ecuador
• ²Escuela Superior Politecnica del Litoral, Guayaquil, Ecuador
• ³Facultad de Ingeniería y Ciencias de la Tierra, Escuela Superior Politécnica del Ecuador, Guayaquil, Ecuador
• ⁴Centro de Investigación y Proyectos Aplicados a las Ciencias de la Tierra, Escuela Superior Politécnica del Litoral, Guayaquil, Ecuador
• ⁵Facultad de Ingeniería en Mecánica y Ciencias de la Producción, Escuela Superior Politécnica del Litoral, Guayaquil, Ecuador
• ⁶Geo-Recursos y Aplicaciones GIGA, Escuela Superior Politécnica del Litoral, Guayaquil, Ecuador
• ⁷Facultad de Ciencias Naturales y Matemáticas, Escuela Superior Politécnica del Litoral, Guayaquil, Ecuador
• ⁸Department of Resources for Ecological Transition, Geological and Mining Institute of Spain, Guayaquil, Ecuador

The selection of optimal sites for solid waste disposal is a critical aspect of management, especially from an environmental and logistical perspective. In Guayas province (Ecuador), many solid waste disposal sites have been implemented without technical-environmental planning, exacerbated by financial constraints that hinder their effective management. Given this context, this study proposes integrating the concept of the Gravity Centre of Waste Production (GCWP) into the traditional criteria for selecting Final Disposal Sites (FDS) by combining Analytical Hierarchical Analysis (AHP) and geographic information systems, strengthening logistics management and the development of intermunicipal partnerships in the north of Guayas province. The study addressed a diagnostic stage, the evaluation of FDS selection criteria, and the identification of suitable areas through mapping. The municipalities present limitations for the adequate operation of FDS, most of which are open-air dumps. Therefore, three groups were proposed as possible partnerships between cantons. The AHP analysis showed that criteria related to water conservation were the highest-scoring, as opposed to land use and land cover. The selected sites are as close as possible to the GCWP for optimal waste disposal. The results were validated through the analysis of four different scenarios and the participation of authorities in charge of territorial management. The proposed methodological approach is a viable alternative for cantons, districts, or municipalities with budgetary constraints, as it seeks to be a helpful management tool for waste disposal within a framework of intermunicipal cooperation.