Suitable site selection for transfer stations in a solid waste management system using analytical hierarchy process as a multi-criteria decision analysis: a case study in Azuay-Ecuador

To guarantee a dignified life in low-incoming countries where socio-environmental negative implications derived from the municipal solid waste (MSW) by its excessive generation, lack of governance, and financial resources, sustainable and integrated solutions are required. From this perspective, well-located transfer stations (TSs) are conceived as an alternative to improve MSW management quality in municipalities that generate little MSW and have long transportation distances. Consequently, this research aims to find optimum areas to locate TSs in the province of Azuay-Ecuador as a commonwealth proposal. It applies a multi-criteria decision analysis based on geographic information systems with the analytical hierarchical process technique: a heuristic and scalable method that simultaneously evaluates subjective and non-monetized inputs. The authors faced it from a holistic perspective in a three-level hierarchical structure; starting from categories: technical, environmental, economic, and social; then criteria: rivers, protected areas, populated areas, land use, educational centers, health centers, tourist sites, basic services, roads, gravity centers, geology, power grid, and slopes; and finally, sub-criteria defined by criteria´s measurable attributes. This research provides local decision-makers with middle-scale tools and a first diagnosis to focus later efforts in local studios over potential sites. The results showed that 79.12% of the study area was restrictive to place a TS. The remaining territory suitability index values between 13 and 89% were found, with possible TSs at Paute, Sigsig, and Nabón to serve nine from fifteen cantons.