Surface Subsidence Monitoring In Xi'an From 2015 To 2019 Based On Time Series InSAR Technology

Land subsidence is a kind of disaster,especially in urban areas,which is particularly harmful to the development of cities and the security of public resources.Therefore,it is very important to monitor land subsidence in cities,especially in large cities.Taking Xi'an city as an example,since the 1960 s,the rapid growth of population and large-scale urban construction have aggravated the surface load.The excessive exploitation of groundwater caused by the increasing demand for industrial and agricultural water is the main cause of land subsidence in the early stage.In recent years,subway construction and ground crack activities have aggravated the occurrence of ground subsidence.SBAS technology and PS-InSAR technology are commonly used InSAR treatment methods,which can be used for long-term surface subsidence monitoring.Therefore,this paper studied the subsidence monitoring of Xi'an city based on SBAS technology and time series InSAR technology.In this paper,the subsidence monitoring work of Xi'an city is mainly carried out in the following aspects:(1)SBAS technique research is used to collect the subsidence in xi'an from 2015 to 2019,calculate the four years of cumulative settlement figure,through to the interference of 59 of the SAR image processing,Xi'an is typical of the eight major are emphatically analyzed the subsidence regularity of subsidence area,in the four years xi 'an accumulated settlement of the biggest area in the Yuhuazhai,the largest settlement reached 518.28 mm.Moreover,the trend of deformation in the Yuhuazhai area changed from October 2018.Instead of subsidence,it started to rise,and then leveled off.This paper also found an ascending region,with a cumulative maximum of +183.23 mm and rising rate of +45.81mm/a in 4 years.(2)The method and means of PS-InSAR technology for simultaneous ground subsidence monitoring in Xi'an were studied,and 59 SAR images in the same period from July 2015 to July 2019 were used for interference processing.The results show that the settlement monitoring by PS-InSAR technology is basically consistent with that by SBAS technology,which verifies the consistency of settlement rules and development characteristics.(3)Using PS-InSAR technology and SBAS technology monitoring results,analysis the surface changes in the Yuhuazhai area.The study found that from September to October 2018,the surface of Yuhuazhai village gradually slowed down.According to the investigation of the municipal construction in Xi'an city,Xi'an city implemented the special project of emergency ground subsidence treatment and groundwater recharge in the Yuhuazhai area in 2018,which may be the main reason for the surface rise in the area from September to October 2018.