关键词: 北京典型区, 地面沉降, 时空演化, 地下水, 城市建设

Abstract:

Since land subsidence was firstly discovered in the 1950s in Beijing city, it has revealed a rapid developing trend. In the past few decades, land subsidence has been increasing in both its range and speed year by year and become one of the most serious disasters affecting the safety and development of Beijing ^[1]. In this paper, we choose four typical subsidence locations as the study area. The land subsidence information of the typical area in Beijing plain during 2004-2010 was used as the primary data source. This is acquired by Permanent Scatterers Synthetic Aperture Radar Interferometry (PS-InSAR) method, which has high accuracy and been widely used in deformation monitoring and land subsidence research. Meanwhile, the conventional monitoring data (1955-2010) was adopted as the supplement data. Then, we analyzed subsidence evolution characteristics from two aspects: spatial distribution and temporal evolution. Combing with the groundwater dynamic monitoring data, the land-use data from remote sensing and the using of GIS spatial analysis, we study the spatial and temporal respond and the important factors affecting land subsidence. The result shows that the seriously affected areas of ground subsidence in Beijing had expanded unceasingly, and the degree of unevenness has been gradually increasing. During the study period, the change of groundwater level had a high consistency with land subsidence in temporal and spatial distribution. In the process of urban development, engineering activities were considered another factor affecting the characteristics of spatial and temporal distribution of land subsidence. In this paper, our research indicated that the excessive exploitation of groundwater is the main influence factor for the subsidence in Beijing; and the rapid development of city leading to large-scale construction is also one of the factors that make the subsidence worse and more serious. The results have considerable referential importance and can provide a scientific basis for the prevention of land subsidence in Beijing.

Key words: Beijing typical area, land subsidence, spatial-temporal evolution, groundwater, urban development