3D Geological Suitability Evaluation for Urban Underground Space Development Based on Combined Weighting and Improved TOPSIS

Urban underground space (UUS) utilization is essential for urban sustainable development, and UUS geological suitability evaluation (UGSE) is crucial for safe and rational UUS utilization and for minimizing development risk. This paper presents a three-dimensional (3D) UGSE framework based on integrated weighting and improved technique for order preference by similarity to an ideal solution (TOPSIS), which enhances the evaluation rationality and accuracy. Analytic network process (ANP) was applied to calculate the subjective weights of the evaluation index. Criteria importance through intercriteria correlation (CRITIC) model improved by the coefficient of variation was applied to calculate the objective weights. The combination weights were further calculated by the game theory (Nash equilibrium model), which can coordinate the conflict and determine the consistency and compromise between subjective and objective weights. Based on the combination weights, the grey correlation analysis (GRA) model was used to refine the TOPSIS model, and combined the Euclidean distance (with the grey correlation) to construct a more reasonable closeness index. This allows the improved TOPSIS model to retain the benefit of better objectivity, while taking advantage of the grey correlation theory with little information. We took the central area of Future Sci-Tech City in China as a case study, and conducted UGSE (based on the above model), together with 3D visualization and analysis. The results support that the combined weighting and improved TOPSIS models can well reflect the varying 3D geological suitability and make the evaluation more robust, which facilitate decision-making in UUS development.