Resumen
Recently, the popularity of anaerobic digestion (AD) has been increasing, and selecting a site for AD is a complex process for both individuals and decision-makers. This process requires the selected site to fulfill all regulation requirements, simultaneously reducing environmental, sociocultural, technical, political, economic, and public health costs. A geographic-information-system-based multi-criteria decision analysis (GIS-MCDA) is presented in this study to evaluate and examine the suitability of the study area in order to propose a suitable site for an AD facility in Oita City, Japan. Multi-criteria evaluation (MCE) was used to standardize the map layers into fuzzy membership functions. The proximity variables were classified into seven factors and three constraint groups, specifically, environmental, sociocultural, and technical/economic criteria. The proximity and criteria maps were combined using weighted linear combination (WLC) techniques, and the resulting suitability map was evaluated on a grading scale of 0–255 B. The analytical hierarchy process (AHP) ranking analysis indicated that an area of about 13.36 km2 from the entire study area is the most suitable and that the remaining two options are still suitable for the intended purpose, but the entire decision will be entrusted to the decision-makers’ judgment.