Abstract:Using PS-InSAR time series technology to process the Sentinel-1A image data from 2018-01 to 2019-12 in Changzhou city, we obtain the ground deformation information of Changzhou city. The results are consistent with leveling data in the same period; the difference between maximum value and average value of the two methods are 6.1 mm and 2.7 mm respectively, and the root mean square error(RMSE) is 1.7 mm. Analysis of the temporal and spatial evolution of land subsidence in Changzhou city shows that the uplift areas are mainly located in cities and towns, with an average cumulative uplift of about 7.3 mm; the subsidence area is mainly located in rural areas, with an average cumulative subsidence of about 7.6 mm; the ground subsidence in some areas such as the southern part of Wujin district is still severe, and the average cumulative subsidence exceeds 15 mm. Finally, we analyze the influence of the second pore confined water on land subsidence, and the correlation coefficient between the two is 0.55; analyzing the rebound situation of each layer of the layer-wise mark, the results show that most of the deep strata are in the rebound stage, and the shallow strata are currently the main layers of soil compression. This result shows that the second confined water has a certain impact on land subsidence and that the impact of soil compression in shallow strata on land subsidence is becoming more obvious.
LI Honghui,HOU Zhandong,LI Shujian. Analysis of Characteristics and Causes of Land Subsidence in Changzhou by Time Series InSAR[J]. jgg, 2022, 42(1): 54-58.