InSAR Monitoring And Analysis Of Longyao Ground Fissure Deformation In North China

Chinese cracks except in Liaoning,Jilin,Gansu,Ningxia,Hubei,Guangdong,Yunnan Province has a scattered distribution,mainly concentrated in the North China Plain over a hundred million square kilometers in the region,It is rare in its wide range,large quantity and long acting time..Because the ground fissure disaster has such characteristics as slow disaster,large disaster area,strong structural damage and strong stage of disaster,ground fissure disaster is one of the key geological disasters in china.The research has i mportant practical significance to the technology of high precision monitoring of cracks and crack formation mechanism,can provide technical support for the government departments of city construction,land use planning and optimization design,major construction projects of national security and save the engineering cost.The research area chosen in this paper is located in Xingtai County,Hebei City,Longyao province.The area has the largest land fissure-Longyao fissure in Hebei plain.As a result of the Longyao ground fissure,the local city construction,agricultural production,people's lives have brought great losses.Based on InSAR technology,large area ground subsidence and ground fissure monitoring are carried out in Longyao area.The main research contents and results are as follows:(1)The characteristics and specific parameters of Sta MPS are analyzed,and the methods of phase stability estimation,PS point selection and deformation estimation are discussed in detail.Firstly,the PS candidate point is determined by the amplitude deviation index,the threshold method and the phase stability estimation.Then the PS candidate points are analyzed and proposed,and the PS points are extracted.Then the DEM error,atmospheric delay and space view error are eliminated,and the final data processing results are obtained.Some suggestions on the selection of different parameters in data processing are also given.(2)Using the 16 scene Envisat data and the 15 scene ALOS data covering Hebei city of Xingtai,PS-In SAR technology was used to monitor the annual average deformation rate of the study area.Analysis and extraction time series feature point area in the research area,and the crack of profile analysis,combined with analysis of geological structure in Hebei fault,The results show that the ground fissures in Longyao are affected by the Longyao fracture zone and regional groundwater exploitation.(3)The high resolution Terra SAR data characteristics were introduced,and the use of TerraSAR data covering 8 scene County of Longyao-Renxian County,resolved to monitor the area by using PS-InSAR technology and SBAS technology,respectively in the area by the average strain rate and time series results.The ground fissures in Longyao wer e measured by field leveling.The results of leveling test of ground fissures in Longyao are compared,and the reliability of In SAR monitoring results is verified.