基于PS-InSAR数据的北京市地面沉降影响因素及其交互作用探测

Detection of Influence Factors and Their Interaction of Land Subsidence in Beijing Based on PS-InSAR

地面沉降是在人类活动与自然因素共同作用下导致地面高程降低的一种局部工程地质现象。现有地面沉降影响因素研究主要关注单一影响因子的作用,大多忽略影响因素间交互作用,从而难以全面揭示地面沉降分布的影响机制。为此,基于北京市永久散射干涉测量(PS-InSAR)沉降数据和其他关联因子数据(如地下水位、可压缩层厚度等),利用地理探测器分析地面沉降影响因子及其交互作用机制。研究发现:①地下水位和可压缩层厚度是影响强度最大的两个因子;②因子间均为双因子增强关系,其中,地下水位和可压缩层厚度分别与其他因子存在交互作用,主要表现为非线性增强,少部分为互相增强。本研究为基于PSInSAR数据的地面沉降影响因素及交互作用定量分析提供了一种有效的思路,研究结论对于指导北京市地面沉降的科学防治具有重要意义,方法也可推广至其他城市地面沉降影响机制分析中。

Land subsidence is an engineering geological phenomenon resulting in the decrease of local ground elevation which is induced by the joint action of human activities and natural factors.Existing studies mainly focus on the role of single influence factor with the less consideration of the interaction among multiple factors.Consequently,it is difficult to fully reveal the influence mechanism of land subsidence distribution.Taking land subsidence in Beijing main urban area as a case study,based on PS-InSAR subsidence data and other factors such as groundwater level,thickness of compressible layer and so on,this paper aims to analyze the influence factors of land subsidence and their interaction by introducing the geographical detector model.The results show that:① The groundwater level and the thickness of compressible layer are the two most influence factors;② The interaction effect of two arbitrary factors is greater than the effect of one single factor,while the interaction of the groundwater level and the thickness of compressible layer with other factors performs mainly in the non-linear relationship with a small number of mutual enhancements.In summary,this study provides an effective quantitative analysis method for influence factors and interaction of urban land subsidence based on PS-InSAR technique,and this findings can contribute to the scientific control of land subsidence in Beijing or other cities.