基于PS-InSAR上海地区地表沉降监测与分析

PS-InSAR-based monitoring and analysis of surface subsidence in Shanghai

城市地表沉降对人类生活影响越来越严重,有效监测地表沉降的方法研究显得尤为重要。为监测上海市的地表沉降状况,使用永久散射体干涉测量(permanent scatterer-interferometric synthetic aperture Radar,PS-InSAR)技术对2019—2020年24景覆盖上海地区的Sentinel-1A数据进行处理,然后使用SRTM1数字高程模型进行残差相位修正,提取了2 a的地表沉降结果。通过对监测结果的沉降速率和沉降累计量进行分析,表明上海市城区主要为不均匀地表沉降,主城区分布多个沉降漏斗,与历史沉降数据对比,个别沉降漏斗与上海市地表历史沉降漏斗数据相对应。通过随机选取地面特征点的地表沉降时序数据,可知地表沉降的形变量在各时间单位上基本一致,其变化趋势有较高的一致性,验证了PS-InSAR监测方法的可靠性。研究结果可为上海市地质灾害防治提供数据支撑和决策依据。

Urban surface subsidence has increasingly severe impacts on human life,making it particularly important to study the methods for effectively monitoring surface subsidence.To monitor the surface subsidence in Shanghai,this study processed 24 scenes of 2019—2020 Sentinel-1A data covering the city using the PS-InSAR technique.After treatment using the permanent scatterer interferometry technique,the residual phase correction was performed using SRTM1 DEM,and the surface subsidence results of the two years were extracted.The analysis of the subsidence rate and cumulative subsidence amplitude in the monitoring results shows that the urban area mainly shows uneven surface subsidence with multiple subsidence funnels,some of which correspond to the historical subsidence data.As shown by time-series surface subsidence data of seldomly selected ground characteristic points,the surface subsidence at these points basically had the same deformation amplitude at different times and highly consistent changing trends,verifying the reliability of the PS-InSAR monitoring method.The results of this study will provide data and decision-making bases for geologic disaster prevention and control in Shanghai.