Monitoring Of Beijing Plain SBAS-InSAR Technique Based On Subsidence

With the rapid development of economyin recentyears,led to sharply increase of groundwater withdrawal on urban area, making a series of ground subsidence problems,and seriously threating to urban infrastructure, rail transportation, construction of underground space. Making people’s production and life security risk, restricts the social economy and regional environment comprehensive, balanced and sustainable development. Beijing is the capital of China, as a great city with a population of more than20million, densely lived in the urban area.With advanced underground space traffic and municipal pipe network, and Beijing is also an important railway hub. Carry out the research about ground subsidence monitoring and preventtechnologyin Beijing plain area,will take great achievement and be significance to ensure the development of city construction and people’s usual life. Differential Interferometric Synthetic Aperture Radartechnology (D-InSAR) own the advantages:monitoring period is short, wide coverage, low cost in application,this technology has a wide range of applicationsin the field of land subsidence monitoring and research. This paper applieda new methodD-InSARthat namedSmall Baseline Subset, SBAS interferometry technology, acquiredthe time series cumulative land subsidence of the Beijing plain area, study andanalysethe monitoring results to get the information of subsidence time-space distributioncharacteristics, influence factors and potential hazards.The main research contents and results are as follow:(1) Introduce the background of land subsidence situation in Beijing and the developmentprocess of InSAR techniquein land subsidence monitoringanddemonstrate the international relevant researches in this area. Then elaborated the basic principle of InS AR, D-InSAR technique and data processing flow, and adopts the technology of the3D-InS AR track method, using three scenes ENVISAT ASAR images preliminary obtained the land subsidence informationof Beijing plain area, as a reference information for the next processing.(2) This study selected the northern of Beijing plains area main subsidence centers, using the method of Small Baseline Subset SBAS-InSAR resolution in20scene ENVISAT ASAR data and10high resolution terrasar-x scene processing, high precision of inversion obtained the scope of the study area in nearly four years time series of the cumulative settlement, monitoring results show that the settlement of northern plains three central area more than140mm/years the largest settlement, and subsidence area increasinglyexpands and gradually connection piece, in recent years, the prevention and control measures and no effective low to reduce the development trend of land subsidence. Will monitor the results and the leveling isoline of comparative monitoring results are verified, in the settlement range and degree are in conformity with the contour leveling results, show that the method of monitoring the accuracy and reliability.(3) According to time sequence cumulated subsidence monitoring results, combined with years of average rainfall, the investigation on active faults, the quaternary thickness of compressible stratum distribution, groundwater aquifer group head contour and other related information, for the time and space distribution characteristics of ground settlement influence factors, and makes a preliminary analysis. And for ground subsidence may be the potential hazards made simple introduction.Finally to summarize full text work and puts forward some problems to be solved in future research work.