Ps-of Insar Subsidence Monitoring Of Typical Areas Of Ground In Beijing

Land subsidence is the loss of regional ground elevation which is caused by the natural or artificial compression and deformation of incompact stratum. It is a one kind of complex environmental and geological problems which has aroused universal concern from home and abroad. It is has the following characteristics:slow onset, long duration, wide extent of influence, complex genetic mechanisms, difficult to control, irreversible, etc. And it is often happened in big or medium-sized city. Therefore, the land subsidence greatly affected people's life and production and sustainable development of the society. The land subsidence in Beijing area first found in 1935. The formation of land subsidence center was quite a long process from shoot to appearance and from development to maturity. Now Beijing Plain has become one of the serious land subsidence regions in China, and its Potential Hazard has attaceted governments at different levels and all circles of society.The traditional means of monitoring land subsidence (Leveling, bedrock bench mark, GPS, etc.), with high precision, but low sampling rate and long period of measurement, have been unable to meet requirements of modern society. Interferometric Synthetic Aperture Radar is a potential technology for the measure of land subsidence, and it overcomes the defects of the traditional methods. Sometimes, D-InSAR is unable to obtain reliable information because of the temporal and spatial decorrelation and atmospheric delay in practical applications. Persistent scatterers interferometry technology can enhance temporal and spatial resolution of the land subsidence monitoring, reduce the temporal and spatial decorrelation and lessen the error that caused by atmospheric delay. Therefore, the persistent scatterers (PS) technology is a very powerful method for obtaining comprehensive land subsidence information.In my paper, I used 29 ASAR SLC images to derive detailed information of the time-varying land subsidence deformation fields over the Beijing Plain area with PS-InSAR techniques (Hooper,2004). The phase unwrapping is processed with the reference district located in the south mountain area. After removing the DEM error, atmosphere and orbit error, we finally obtained the time series deformation results for the study area. The new PS results are basically consistent with the result of the leveling. By contrast the results of PS-InSAR and the leveling. Furthermore, we analysis the trend and the evolution of the land subsidence in Beijing Plain, the preliminary analysis has evolved into the mechanism. This result is referable and useful for prevention and control of the land subsidence in Beijing area.