The integration of solar photovoltaic (PV) systems in urban environments promises great potential for sustainable energy applications. However, the unique characteristics of cities, the varieties of weather that occur at the place, and technology inefficiency make performance evaluation difficult. This paper sought to address the pressing need for a robust performance evaluation framework for urban solar PV systems by developing a disc spherical fuzzy aggregation framework. It develops basic algebraic aggregation operations in the framework of the disc spherical fuzzy set (D-SFSs), proving their completeness and describing their essential characteristics. These new operators conceived to operate on D-SFSs furnish theoretical robustness and provide the foundation for decisions made. A shining novel disc spherical fuzzy method is developed namely combinative distance-based assessment (CODAS) in D-SFS. A case study regarding the application of this model in the assessment of performance by urban solar PV systems is being conducted, thus proving the application aspect. Results come out positive in interpreting the decision-making dilemma and differences among several experts. This would, therefore, encourage various sectors to expand the use of D-SFSs in decision support systems and similar areas by showing how useful they can be in actual situations.

Flooding is one of the most widespread and damaging natural hazards worldwide, causing significant economic losses, environmental degradation, and risks to human life, particularly in vulnerable watersheds. The multi-criteria decision-making dilemma of managing flood risks in prone watersheds is associated with conflicting economic, social, and environmental objectives. To assess and rank the flood risk management options, this research suggests a single model that should be developed using a mix of the fuzzy analytic hierarchy process and ELECTRE III approaches. The fuzzy analytic hierarchy process is used to capture the uncertainty and subjectivity of the pairwise comparison of decision-makers. Alternative management strategies are ranked using the ELECTRE III technique. The suggested approach is applied to an empirically vulnerable watershed, demonstrating its viability. The suggested fuzzy framework aids decision-makers in selecting the best course of action even before a flood occurs. Watershed managers can use the findings as a scientifically validated tool for resource allocation in flood risk reduction, as they provide a clear and sound hierarchy of strategies that include both structural and non-structural measures.