湖州市东部平原区地面沉降易发性及风险评价

Susceptibility and Risk Assessment of Land Subsidence in the Eastern Plain of Huzhou City

摘要: 随着城市化水平的不断提高，地下水超采、工程建设等人类活动逐渐加剧，使得地面沉降现已成为我国城市主要的地质灾害之一。文章综合考虑软土层厚度、松散层厚度、含水层数量、含水层厚度、地下水开采强度、多年平均沉降速率等因素对湖州市东部平原区地面沉降易发程度进行分区，同时，结合地面累计沉降量、地面沉降速率、地面高程、城市人口密度、建设用地占比等评价指标，采用定性与定量相结合的方式进行地面沉降风险区划分。结果可知，湖州市东部平原区无地面沉降高易发区，有地面沉降中易发区2个、地面沉降低易发区1个、地面沉降不易发区1个；全域无地面沉降高风险区，中风险区主要集中在南浔区南浔镇北东部，面积34.28 km²，占地面沉降易发区面积的2.72%；低风险区主要集中在吴兴区基岩山区外全部区域、南浔区西侧大部、德清县全部，面积1223.91 km²，占地面沉降易发区面积的97.28%。研究结果对于指导湖州市国土空间科学规划，提高城市应急管理水平具有积极的现实意义。

Abstract: With the continuous improvement of urbanization level, human activities such as groundwater overexploitation and engineering construction have gradually intensified, making land subsi-dence one of the major geological disasters in China’s cities. This paper comprehensively consid-ers the thickness of soft soil layer, the thickness of loose layer, the number of aquifers, the thick-ness of aquifers, the intensity of groundwater exploitation, the average annual settlement rate and other factors to divide the land subsidence prone degree in the eastern plain area of Huzhou City. At the same time, combined with the cumulative ground subsidence, land subsidence rate, ground elevation, urban population density, construction land proportion and other evaluation indicators, the land subsidence risk area is divided by combining qualitative and quantitative methods. The results show that there is no high land subsidence prone area in the eastern plain area of Huzhou City, and there are 2 middle land subsidence prone areas, 1 difficult land subsidence prone area and 1 low land subsidence prone area. There is no high-risk area of land subsidence in the whole region, and the medium-risk area is mainly concentrated in the northeast of Nanxun Town, Nanxun District, with an area of 34.28 km², accounting for 2.72% of the area prone to land subsidence. The low-risk areas are mainly concentrated in all areas outside the bedrock mountainous area of Wuxing District, most of the west side of Nanxun District, and all of Deqing County, with an area of 1223.91 km², accounting for 97.28% of the area prone to land subsidence. The results of this paper have positive practical significance for guiding the scientific planning of land and space in Huzhou and improving the level of urban emergency management.