厦门市地面沉降影响分析与风险评价

Impact analysis and risk assessment of urban land subsidence in Xiamen City

城市的地面沉降一直以来都是沿海城市密切关注的问题。在沿海城市对高层建筑群诱发的地面沉降进行深入研究具有重要意义。获取地面沉降监测点的高程信息,分析了厦门市地面沉降情况与空间差异性。重点探讨建设用地、建筑容积率与土地利用转化信息这3种因素对厦门市地面沉降的影响,并对厦门岛地面沉降风险进行评估,可为厦门岛的高层建筑三维空间布局与优化研究提供先验知识。结果表明:(1)在2001—2015年厦门市整体的高程存在下降的趋势且较为缓慢,同时厦门市的城市建设规模不断变大且建设面积增速不断增大,与厦门市的城市地面的沉降发展趋势相同。(2)厦门市的高层建筑密度需达到一定程度才对地面沉降有影响,厦门岛的建筑容积率与地面沉降没有存在显著的相关性。(3)在不同土地利用转化建设用地对地面沉降的影响中:原水域用地沉降最为明显,建成时间越长,总沉降量越大;原耕地用地转化成高层建筑之后沉降有明显发生,也随着建成时间的延长有逐渐增加沉降量的态势;原园地、林地用地沉降只在少部分地区发生且与建成时间无明显差别。(4)厦门岛可用于城市建设区域中的53.34%是地面沉降中风险等级以上的。此外,本研究给出防御防治城市地面沉降风险的有效建议与措施。本研究结果可为厦门市城市化进程中的地面沉降监测、规划设计与决策等提供重要的数据支撑,为城市可持续发展提供科学的依据;也可为国内外其他城市的地面沉降监测分析和可持续发展研究提供理论依据和借鉴意义。

Urban land subsidence has always been a problem that coastal cities pay close attention to.It is of great significance to conduct in-depth research on land subsidence which was induced by high-rise buildings in the coastal cities.In this study,the elevation information of land subsidence monitoring sites were firstly obtained to analyze the spatial difference of land subsidence in Xiamen City.Secondly,the influence of construction land,floor area ratio and land use conversion information on land subsidence in Xiamen City was discussed emphatically.The land subsidence risks of Xiamen Island were evaluated,which can provide a priori knowledge for the research on three-dimensional layout and optimization of high-rise buildings in Xiamen Island.The results show that:(1)from 2001 to 2015,the overall elevation of Xiamen City presented a downward trend and was slow.Meanwhile,the urban construction scale continued to increase and the construction area increased in Xiamen City,which were the same as the development trend of urban land subsidence in Xiamen City.(2)The density of high-rise buildings needs to reach a certain degree to have an impact on the land subsidence in Xiamen City.There is no significant correlation between floor plot ratio and land subsidence in Xiamen Island.(3)Among the impacts of land subsidence due to different land transformed construction land,the original water area total land subsidence is the most obvious.The longer the completion time,the greater the amount of subsidence.After the original cultivated land conversion into high-rise buildings,the settlement obviously occurred.With the extension of the construction time,the settlement increases gradually.The settlement of the original garden and forest land only occurs in a small number of areas and there is no significant difference from the completion time.(4)Xiamen Island can be used in urban construction areas where 53.34%of it is above the risk level of land subsidence.In addition,the effective suggestions and measures are also given to prevent the risk of urban land subsidence in this study.The results of this study can provide important data support for land subsidence monitoring,planning,design and decision-making in the urbanization process of Xiamen City,and provide a scientific basis for the sustainable development of the cities.The results can also provide theoretical basis and reference significance for the land subsidence monitoring analysis and sustainable development research for other cities at home and abroad.