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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. [ABSTRACT FROM AUTHOR]

Now ground source heat pump is a more efficient way to develop and utilize shallow geothermal energy because it is clean and environmentally friendly and has a relatively low energy cost. In order to optimize the planning layout and geographical space development in the eastern new town of Anqing city, which can realize the transformation and upgrading of real space and urban sustainable development, the exploration for shallow geothermal energy will be carried out in this area, so as to find out the comprehensive thermophysical parameters of the shallow rock-soil body and the heat transfer capacity of the vertical heat exchanger, etc. This paper takes the CBD in the eastern new town of Anqing as an example to provide the basis for the feasibility construction of the ground source heat pump project in the study area and evaluate the economic and environmental benefits of the expected project. According to the simulation test data of 5 working conditions of 4 geothermal exploration holes in the study area, we can clearly know that the energy cost per square meter of the ground source heat pump is 11.8 yuan for a building of one hundred thousand square meters in which the heat removal power is expected to be 9481 kW in summer and 3070 kW in winter. And the annual emission of carbon dioxide, sulfur dioxide, nitrogen oxides, suspended dust, and other air pollutants to the atmosphere can be reduced by 1442.5 t, and the solid waste ash and slag can be reduced by 59.7 t. The annual environmental treatment cost will be saved by 166000 yuan. [ABSTRACT FROM AUTHOR]