采用时序InSAR技术的广汉市地面沉降监测及影响因素分析

随着城市化进程的不断推进，建设施工活动和地下水开采等频繁人类活动对城市地表稳定性的影响程度逐步加深。基于2018年3月~2021年12月的Sentinel-1A数据，结合永久散射体干涉技术中利用振幅离差指数提取高相干点的方法，采用小基线集干涉技术，获得了广汉市的地面沉降速率和沉降时序，据此分析了广汉市沉降的特征及原因。结果表明，在研究时段内，广汉市接近90%的地区未出现严重沉降现象，小汉镇、金雁街道、三星堆镇和向阳镇出现小规模沉降，施工区及其周边沉降相对严重，最大沉降速率为-31 mm·年-1。此外，沉降主要出现在2018~2020年，建筑施工活动和降水是引起地面沉降的主要因素。

Land Subsidence Monitoring and Influencing Factors Analysis in Guanghan City Using Time-series InSAR Technology

As urbanization progresses, the influence of frequent human activities such as construction and groundwater exploitation on the stability of urban surface is gradually deepening. Based on Sentinel-1A data from March 2018 to December 2021, the land subsidence rate and time series of Guanghan were obtained by using the small baseline subset interferometry technology, which combined with the method of extracting high coherence points by the amplitude dispersion index in permanent scatterers interferometry technology, and the analysis of settlement characteristics and causes in Guanghan was conducted. The results show that during the research period, almost 90% of Guanghan do not suffer from severe subsidence, Xiaohan Town, Jinyan Street, Sanxingdui Town and Xiangyang Town experience small-scale settlement. In addition, the settlement in and around the construction area is relatively serious, with a maximum settlement rate of -31 mm·year-1. Furthermore, settlement mainly occurs between 2018 and 2020, and construction activities and precipitation are the main factors causing land subsidence.