Abstract: Surface subsidence is one of the global geological hazards problems. Rapid subsidence of the ground can lead to surface collapse, which can damage underground pipelines as well as surface buildings and eventually cause huge economic losses and even casualties. This geological hazards problem is particularly acute in China, where underground projects and surface buildings are undergoing massive expansion. There are many methods to monitor the surface deformation, such as level measurement, GPS, InSAR technology and so on. However, usually these techniques can only quantitatively analyze the elevation change of the ground surface, but cannot find out the causative factors for the occurrence of disasters, and lack qualitative analysis of the spatial and temporal characteristics of the ground settlement. In this paper, the InSAR technology is combined with the hydrogeology characteristics of the area. It takes the Puning area in Guangdong as an example, to realize the whole process of surface subsidence monitoring from data acquisition and processing to the analysis of the causes. In this paper, this analysis method not only investigates the subsidence area in the Puning city area, but also provides a systematic analysis of the causes behind it, which provides a more scientific guidance for the subsequent prevention and control measures.

Key words: surface subsidence, InSAR technology, geological characteristics, Puning city