Beyond suitability maps: A GIS-MCDM decision-support framework for robust and demand-oriented siting of plasma...

Plasma gasification is a sustainable alternative to conventional waste management. However, facility siting is challenging due to multiple trade-offs and uncertainty, often leading to large suitability zones that are difficult to implement in practice. This study proposes a spatial GIS-MCDM decision-support framework for pre-implementation siting of plasma gasification facilities and applies it to Isfahan Province, Iran. The framework combines fuzzy expert-based weighting (Fuzzy-SWARA) with GIS-based spatial aggregation to evaluate multiple siting criteria. Uncertainty is addressed through global sensitivity analysis using fuzzy logic, bootstrap resampling, and Sobol indices to evaluate how site suitability responds to changes in criteria importance. Based on these analyses, a composite robustness index (RI) is developed by integrating suitability, range, and probability maps to identify locations that remain stable under uncertainty. Multi-stage decision analysis is then used to refine suitability results and select robust and demand-covering candidate sites. The results show that only 0.33% of the study area achieves high suitability (site suitability index [SSI] > 0.8); however, the framework identifies 1-3 stable sites that remain robust under uncertainty while maximizing waste generation index coverage. This approach achieves an efficient balance between waste transport distances, land use, and the number of required facilities. Compared with sanitary landfilling, plasma gasification requires 85-94% less land, easing site selection and reducing pressure on land resources. Overall, the proposed framework moves beyond descriptive suitability mapping and provides decision-ready, land-efficient guidance for waste-to-energy siting in uncertainty-prone regions.