北京典型区地面沉降演化特征与成因分析

北京从20世纪50、60年代发现地面沉降以来,其一直呈快速发展的态势。在过去的几十年里,北京市地面沉降的范围和速度逐年增加。本文以北京市典型地面沉降区为研究区,选择永久散射体合成孔径雷达干涉测量技术所获取的2004-2010年间北京地面沉降信息作为主要数据源,补充水准测量数据（1955-2010年）,从空间分布和时序变化2个角度,分析北京市平原典型区地面沉降演化特征。结合地下水动态监测网数据、土地利用数据,采用GIS空间分析,研究各因素和地面沉降之间的时空响应关系。结果表明,北京地区地面沉降严重区域面积不断扩大,且局部不均匀程度逐渐增加。在研究期内,地下水水位变化在时间和空间上与地面沉降有较高的一致性,地下水超量开采是影响北京地区地面沉降的最主要因素,而城市发展过程中的工程活动也是影响地面沉降时空分布特征的因素之一。研究结果可为北京市地面沉降防控提供一定的科学依据。

Evolution and Genetic Analysis of Land Subsidence in Beijing Typical Area

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.