融合 PS、SBAS、DS InSAR 技术的昆明地面沉降研究

The Study on Land Subsidence in Kunming by Integrating PS,SBAS and DS InSAR

时序InSAR技术为城市地面沉降监测和防治提供了有效方法,然而PS-InSAR和SBASInSAR技术自身的缺陷限制了InSAR技术的监测精度,特别是复杂地形产生的低相干性引起的PS点稀疏问题。在PS和SBAS算法基础上,通过引入Stacking技术联合PS-InSAR进行相干目标点选取,提出融合PS、SBAS、DS-InSAR的技术,并对比提出的方法与常规PS+SBAS-InSAR的监测结果。研究结果表明:提出的方法与PS+SBAS-InSAR反演的昆明沉降速率结果存在较好的一致性,其中本实验提出的方法能增强观测区域点目标空间分布的密度,进而得到更多有效的地表形变信息。从整个研究区来看,昆明市城区地表整体存在-22~8 mm/a的沉降速率,严重沉降区集中在官渡区、西山区和五华区,并已经形成多个沉降漏斗。自1989年以来,小板桥和河尾村依然是最严重的两个沉降漏斗中心,而东北方向的蒋家营则是本次研究中发现的新沉降点。结合历史资料的验证分析表明:昆明地面沉降主要受地下水抽汲、建筑荷载与工程施工以及断陷盆地的构造运动的影响。

Time-series InSAR technology provides an effective method for monitoring and controlling land sub‑sidence in Kunming city.However,the defects of PS-InSAR and SBAS-InSAR technology limit the monitor‑ing accuracy,especially the low coherence of PS points caused by complex terrain.In this paper,we proposed InSAR technique combining PS,SBAS and DS to monitor the subsidence in Kunming urban area,and the re‑sults of the proposed method are compared with PS+SBAS-InSAR.The results show that the proposed meth‑od is in good agreement with the results of the Kunming subsidence rate inversion by PS+SBAS-InSAR,and the proposed method can enhance the spatial distribution density of the points in the observation area and obtain more effective surface deformation information.From the perspective of the whole study area,the subsidence rate of the urban surface of Kunming city is-22~8 mm/a,and the serious subsidence areas are concentrated in Guandu District,Xishan District and Wuhua District,and several subsidence funnels have been formed.Since 1989,Xiaobanqiao and Hewei Village are still the two most serious subsidence funnel centers,while Jiangjiay‑ing in the northeast is the new subsidence point found in this study.Combined with the analysis of historical da‑ta,it is shown that the ground subsidence in Kunming is mainly affected by groundwater pumping,building load,engineering construction and tectonic movement of faulted basin.