DEFORMATION MONITORING OF GROUND FISSURE WITH SAR INTERFEROMETRY IN QINGXU,SHANXI PROVINCE

Recently,as investigated,the ground fissure in Qingxu of Shanxi province is one of the most active fissures in Fenwei Basin. It has caused serious damages to surface infrastructures such as roads and buildings.In order to monitor the deformation of the Qingxu fissure and to deduce its cause,this paper uses the differential SAR interferometry technique(D-InSAR).In order to mitigate the temporal decorrelation over the farm region, two scenes of Envisat ASAR data with only 70 days intervals in 2007 are selected and used to generated surface deformation results.Firstly, a subsidence of cone shape is detected as an ellipsoid with 2km long axis located in the south of Qingxu fissure. Then two profiles paralleling to the fissure and eight profiles normal to the fissure are taken to analyze the spatial characteristics of the fissure. It is found that the main deformation area is located in the south of the fissure. The maximum influence width is up to 100 m. Besides, it is found that the activity of ground fissure in different areas is greatly different. The maximum land subsidence difference crossing the ground fissure is up to 5 cm. Finally, the Jiaocheng fault is deduced to control the location of Qingxu fissure. The great land subsidence is the main sake for unusual activity of Qingxu fissure.