PS-InSAR技术与多光谱遥感建筑指数的载荷密度对地面沉降影响的研究

城市快速发展带来的载荷增加在一定程度上加剧着局部的地面沉降。选取覆盖北京平原区的TM多光谱遥感影像，反演基于指数的建筑用地指数，表征建筑用地(载荷)时空密度差异信息;进而基于永久散射体干涉测量监测技术和遥感建筑指数，结合GIS空间分析方法，从像元角度，分析典型区域载荷变化与地面沉降的相关性。结果表明：(1)载荷的密度与沉降的不均匀性存在正相关关系，尤其在高沉降速率地区体现的较为明显;(2)由于地质结构、土体结构的复杂性、滞后性等特点，使得在相对较短周期研究内，载荷的增加对地面沉降的影响并不十分凸显;(3)高密度建筑群使得局部地面荷载增加，各单体建筑的附加沉降互相叠加，对区域性地面沉降的贡献是不容忽视的问题。

The Impact of Load Density Differences on Land Subsidence Based on Build-Up Index and PS-InSAR Technology

The excessive mining for underground water is the main reason inducing the land subsidence in Beijing, while, increasing of load brought by the urban construction aggravate the local land subsidence in a certain degree. As an international metropolis, the problems of land subsidence that caused by urban construction are becoming increasingly highlights, so revealing the relationship between regional load increase and the response of land subsidence also becomes one of the key problems in the land subsidence research field. In order to analyze the relationship between the load changes in construction and the land subsidence quantitatively, the present study selected the TM remote sensing image covering Beijing plain and used Erdas Modeler tool to invert the index based on building site (IBI), acquired the spatial and temporal change information in research area further; Based on results monitored by PS-InSAR (permanent scatterer interferometry) and IBI index method, and combined with the GIS spatial analysis method in the view of pixels in different scales, this paper analyzes the correlation between typical area load change and land subsidence, The conclusions show that there is a positive correlation between the density of load and the homogeneity of subsidence, especially in area which has a high sedimentation rate. Owing to such characteristics as the complexity and hysteretic nature of soil and geological structure, it is not obvious that the land subsidence caused by the increase of load in a short period. But with the increasing of local land load made by high density buildings and additional settlement of each monomer building superposed with each other, regional land subsidence is still a question that cannot be ignored and needs long-term systematic research and discussion.