利用时序InSAR技术反演塘沽地区沉降历史

Inversion of Subsidence Based on Temporal InSAR Method in Tanggu Area

以塘沽区为研究对象，对1992～1998年间的19景ERS-1／2影像，采用时序InSAR技术反演其由过量开采地下水引起的沉降历史。采用三次多项式模拟实际沉降模型，精确获取sAR成像时间点的下沉值，与反演值对比验证，结果表明，时序InSAR技术反演的历史累积沉降信息与水准数据一致，两者的平均沉降速率之差在5mm／a以内；研究区域以20～50mm／a的速率在整体下沉，西部地区下沉最为严重。

The temporal InSAR technique overcomes the temporal/spatial decorrelation with the slow decorrelating filtered phase （SDFP） pixels identified by phase stability. In this paper, the Tanggu area has been selected as study area, where the subsidence information due to groundwater overexploitation from May 1992 to December 1998 has been inversed by processing 19 ERS-1/2 acquisitions using the temporal InSAR method. The subsidence in time of the SAR imaging has been estimated accurately using cubic polynomial model. And the result derived from temporal InSAR was consistent with the level data which was regarded as GCPs with a little difference that less than 5 mm/a. Besides, the result also showed that the whole study area has suffered subsidence with a mean rate 20-50 mm/a during 1992 to 1998, and the subsidence is severity in the eastern.