基于时序InSAR的常州市2015-2018年地面沉降监测

Ground subsidence monitoring during 2015-2018 in Changzhou based on time series InSAR method

地面沉降不仅会对城市公共基础设施造成安全隐患,也会对当地的经济、环境和可持续发展造成影响.常州市位于我国著名的苏锡常地面沉降带,也是长三角地区的重要城市之一.地面沉降监测一直是该地区掌握地面沉降状态、预防地面沉降灾害的重要举措.利用2015年5月至2018年5月期间的36景Sentinel-1A的IW(Interferometric Wide Swath)模式的SLC(Single Look Complex) SAR(Synthetic Aperture Radar)数据,基于时序InSAR(Interferometric Synthetic Aperture Radar)方法对常州市地面沉降进行了监测,获得了常州地区该时间段年均沉降速率和时序地表累计形变图,揭示了观测期间常州市各地区详细的地面沉降时空分布和变化特征.结果表明,在2015-2018年整个观测期间,常州地区地表形变呈现出"整体相对稳定,武进区局部沉降和抬升较为突出"的特征,与该地区历史沉降监测结果具有良好的一致性和延续性.这一监测结果有助于全面掌握常州地区最近的地面沉降状况,建立并完善长期、连续的地面沉降时空演化监测记录,为城市基础设施选址、规划以及建立预警预报机制等提供决策依据.

Ground subsidence can cause damage to urban infrastructure,and thread adverse impacts on local ecnomic,environment and sustainable development. Changzhou is located in"Su-Xi-Chang"land subsidence zone in China,and is one of the most developed cities in Yangzi delta zone. Ground subsidence monitoring has been an important measure to understand the situation of ground subsidence and mitigate its damage. In order to fully understand the spatial-temporal distribution and feature of ground subsidence in Changzhou,we adopted SBAS(Small Baseline Subset) InSAR(Interferometric Synthetic Aperture Radar) method to 36 SLC(Single Look Complex) SAR(Synthetic Aperture Radar) data acquired by Sentinel 1A in IW(Interferometric Wide Swath) mode from 2015-2018. The LOS(Line of Sight) linear deformation rate map was generated and time-series of ground deformation were derived. The results show that most of the research area remains comparatively stable during the observation period,except for some areas in Wujin district,where obviously ground subsidence and uplift were detected. Detailed spatial-temporal ground subsidence analysis was analyzed in different district of Changzhou city. This result shows coincident with previous monitoring results and helps to fully understand the spatial-temporal characteristics of ground subsidence in the research area. It also helps to establish continuous monitoring records and provides valuable information for site selection and planning for new urban constructions,establishing early warning systems and forecasting mechanism for urban gound subsidence hazards.