Research On The Adaptability Evaluation Of Underground Space Development And Utilization In Nanning City

Since the 21 st century,with the rapid development of urbanization in my country,the number of large cities has increased sharply,and the population has gradually poured into large cities,resulting in rapid saturation of urban population density,urban traffic congestion,and extreme shortage of space resources,which have seriously restricted the sustainability of cities development of.Therefore,the development of underground space is conducive to alleviating the problem of insufficient urban space resources,and is an effective way to solve the problems of urban overpopulation and ground traffic congestion.At present,in the development of urban modernization,underground space has become an important reserve space resource for each city.However,the unreasonable development of underground space by mankind will lead to the waste of limited space resources and the occurrence of geological disasters.Therefore,it is necessary to scientifically establish an underground space suitability evaluation model to scientifically plan and guide the subsequent development of the city.The research area of this thesis is the central area of Nanning.The interior of the research area is highly urbanized and human engineering activities are strong.This paper selects five comprehensive indicators and fourteen single-factor indicators for this evaluation after investigating the basic geological background of the study area,karst development and distribution characteristics,analysis of geological environmental problems,and discussion of urban development status,and uses hierarchical analysis The method and the rough set theory method are combined to assign and calculate the weights.The fuzzy comprehensive evaluation method is used to evaluate the adaptability and partition of the study area,and the following conclusions are obtained:(1)The main constraints on underground projects in the study area are karst development,the distribution of special soils in the area,the impact of groundwater on the project,and the distribution of environmental disasters.The area where the sports center is located in the study area is strongly karst,the northwestern part of the sports center is weak to moderately developed,and the east and southeast are generally moderately developed;the swelling and shrinking soil in the study area has the greatest impact on the project.The upper stagnant water and karst water in the groundwater have the most serious impact on it.The main natural disasters in the study area are divided into geological disasters and flood disasters.(2)At present,in the selection of suitability evaluation methods,the subjective opinions of experts should be considered,but the subjectivity of people should not be overly dependent,which will lead to excessive weighting of some indicators.Therefore,this article weighs and analyzes the pros and cons of multiple evaluation methods,selects the subjective weighting expert-analytic hierarchy process and the rough set theory method,determines the weight after comprehensive analysis and calculation,and then obtains the evaluation result through the fuzzy comprehensive evaluation method.The results are relatively scientific,accurate and in line with reality.(3)From the analysis of the subjective weight value,the topography is more important than other indicators,with a weight value of 0.3218,followed by the current situation of the urban area.The objective weight value indicates that environmental geology is the most important,with a weight value of 0.2566.Taking into account that the hydrological engineering geology of the Nanning Basin is relatively good,most of the conditions can be solved by human control.In recent years,the risk of geological disasters and flooding has been greatly reduced through the construction of protection projects,so subjectively consider the topography and the current situation of the urban area It is more important to Nanning City at present,but from an objective point of view,the impact of environmental geology is also extremely important.(4)In this paper,each single factor index of the study area is converted into a grid map for calculation.The results are divided into four levels: excellent adaptation area,medium adaptation area,poor adaptation area,and extremely poor adaptation area.The evaluation result is excellent adaptation area It accounts for 43.9%,moderate adaptation areas account for 51.1%,and poor adaptation areas account for4.5%.