基于短基线子集(SBAS)干涉技术的地表时序沉降估计

目前我国很多城市正在遭受地面沉降的地质灾害,长三角地区尤为严重,其持续时间长,规模大,带来的经济损失 巨大,无锡是长三角地区大规模地面沉降的典型代表城市之一。为此,本文利用 10 景 ALOS PALSAR 影像,基于短基线子 集(SBAS)干涉技术,评估了无锡市从 2007 年 1 月 12 日到 2011 年 3 月 10 日的地表时序形变。研究结果表明:惠山区沉降速率 较快;2007 年到 2009 年沉降空间格局发生了改变,2009 年到 2010 年监测结果出现异常陡降。实验证明利用短基线子集 (SBAS)干涉技术对大范围的长时间序列沉降监测可行且有效,其监测结果可以让决策者全面掌握地面沉降灾害的整体状 况,从而为地理国情监测以及防灾减灾提供重要的科学依据,同时也可以根据沉降规律追溯历史工程活动时间 。

Application of Small Baseline Subsets D-InSAR Technology to Estimate the Time Series of Land Subsidence

At present, the geological disasters of ground subsidence occur in many cities of China, which are particularly severe in the Yangtze River Delta region where subsidence has long duration, large-scale causing huge economic losses. Wuxi is one of the typical cities of the large-scale land subsidence in Yangtze River Delta. In this article, we use ten ALOS PALSAR images, the time series of land subsidence of Wuxi city from January 12, 2007 to March 10, 2011 is estimated using the small baseline subsets D-InSAR technology. The results show that obvious subsidence occurred in the Hui Shan area, and the settlement in other areas is relatively stable with the average settlement about 15 mm; The settlement spatial pattern changed during 2007-2009, but the settlement rate increased from 2009 to 2010. Experiments prove that the short baseline subset (SBAS) interference in long time series of large-scale subsidence monitoring is feasible and effective. The results of monitoring ground subsidence provide an important scientific basis for disaster prevention and mitigation, and enable policy makers to make the right decisions. In the meantime, we can also trace the history of engineering activities according to the subsidence.