采用2014年10月22日至2019年4月11日之间的26景Sentinel-1 升轨数据,基于PS InSAR技术对蓟运河断裂这一隐伏断裂进行形变监测试验。结果表明:(1)研究区受地面沉降干扰强烈地区在南部宁河一带,向北地面沉降逐步减弱,在蓟运河断裂北段以北一带基本无地面沉降现象。(2)研究区北部的视向线形变速率在蓟运河断裂北段一带在0mm·a-1左右,向北随远离断裂形变速率增大,表明研究区北部受近东西向燕山隆起控制,有向南掀斜运动的趋势。(3)蓟运河断裂北段活动方式为黏滑,其两盘的视线向相对形变速率差约为1.83 mm·a-1,蓟运河断裂南段两盘形变速率差小于2.96 mm·a,与2005—2012年的水准测量结果相近,表明蓟运河断裂2005年以来活动速率较为稳定。(4)在受到地面沉降影响下,隐伏断裂的InSAR形变场包含更多的非构造信息,无法获取断裂的具体形变速率。但断裂活动会导致断裂两盘含水层厚度不同,地下水超采造成的地面沉降幅度也不同,相应的其InSAR形变场在断裂两盘出现突变,对隐伏断裂的位置判定有一定意义。
Based on 26 scenes of Sentinel 1 ascending data from October 22, 2014, to April 11, 2019, the deformation monitoring test of the Jiyunhe fault, a buried fault, was carried out using the PS InSAR technology. Results show the following:(1)The Ninghe area in the south of the study area is strongly disturbed by land subsidence, which leads to gradual weakening toward the north and basically disappears in the north of the northern segment of the Jiyunhe fault.(2)The deformation rate of the northern part of the study area in the direction of the line of sight(LOS)is about 0 mm/a in the northern segment of the Jiyunhe fault and increases northward with the distance from the fault, indicating that the northern part of the study area controlled by the nearly EW trending Yanshan uplift has a trend of tilting toward the south.(3)The movement mode in the northern segment of Jiyunhe fault is stick slip. The difference in LOS relative deformation rate between the two sides is about 1.83 mm·a-1,while that between the two sides of the southern segment of the Jiyunhe fault is less than 2.96 mm·a-1,which is close to the leveling results from 2005 to 2012, indicating that since 2005, the Jiyunhe fault has been relatively stable.(4) Under the influence of land subsidence, the InSAR deformation field of buried fault contains a lot of non structural information, so the specific deformation rate of a fault cannot be obtained. However, the aquifers on the two sides of the fault have different thicknesses due to the fault activity. The land subsidence amplitude caused by groundwater overdraft is also different. Correspondingly, the InSAR deformation field changes abruptly on the two sides of the fault, which is of certain significance in determining the location of hidden faults.
张文朋,张春丽,高武平,闫成国.基于PS-InSAR的蓟运河断裂震间形变监测研究[J].地震工程学报,2023,(1):120-129. ZHANG Wenpeng, ZHANG Chunli, GAO Wuping, YAN Chengguo. Interseismic deformation monitoring of the Jiyunhe fault based on PS InSAR[J]. China Earthquake Engineering Journal,2023,(1):120-129.复制