Intergrading Geological Resource Potential in Landfill Siting: A GIS-SMCE Approach in a Volcanic Landscape of Probolinggo, Indonesia

The selection of suitable landfill sites is a critical challenge in rapidly urbanizing regions, where improper siting may cause long-term environmental degradation, public health risks, and land-use conflicts. This study integrates geological resource potential into a GIS-based Spatial Multi-Criteria Evaluation (SMCE) framework for landfill site selection in Lumbang District, Probolinggo Regency, East Java, Indonesia. The methodological approach combines the Indonesian National Standard for landfill siting (SNI 03-3241-1994) with the Analytical Hierarchy Process (AHP) to determine parameter weights, ensuring both regulatory compliance and scientific transparency. Four key parameters—lithology, groundwater depth, slope gradient, and rainfall intensity—were evaluated, supported by exclusion criteria such as proximity to settlements, rivers, and geological hazards. The final suitability index was calculated using a Weighted Linear Combination (WLC), producing a comprehensive landfill feasibility map. Results indicate that volcanic breccia formations with medium to deep groundwater conditions and gentle slopes (0–20%) offer the highest suitability, with Boto Village identified as the most feasible location. Importantly, the integration of geological resource potential as an exclusion criterion differentiates this study from previous approaches, preventing future conflicts over mineral and groundwater use. Despite limitations in DEM resolution, rainfall data, and resource inventories, the model demonstrates the necessity of incorporating environmental geology into landfill planning. The findings provide a robust decision-support tool for local authorities, offering policy recommendations to update the national landfill siting standard and strengthen sustainable waste management strategies in volcanic landscapes.