Deformation Monitoring And Analysis Of Dams With Time Series InSAR Technology

As a water conservancy project,dam has a positive significance to the economic development of the society and the livelihood of the people by the capacities of water resources regulation,power generation,flood control and drought resistance.At present,the construction and operation of the dam is a mature subject all over the world.Since end of last century,along with the large-scale development of economic construction in China,there had came a large number of dam construction projects.Now,dams in China are not only in a large quantity,but also have the world’s leading quality,for example,the world’s largest concrete gravity dam,the Three Gorges Dam,and the world’s highest concrete arch dam,the Xiaowan dam,etc.The construction and application of these world-class dam projects represent the brilliant achievements of China in the field of dam construction.Because the operation of the dam is directly related to the safety of lives and tremendous property in the reservoir area and downstream,the larger the dam is,the more it needs to ensure its safety operation.The deformation monitoring for the state of the dam is necessary.At present,the dam deformation monitoring is mainly dependent on the traditional ground monitoring means which need a lot of manpower and material resources.Since its appearance in the last century,InSAR technology has been widely used in the field of surface deformation monitoring with its advantages of all-time,all-weather,wide range and high precision resolution.With the development in recent years,PS-InSAR has been able to achieve millimeter deformation monitoring,which makes it possible to use InSAR to monitor the deformation of the dam.Especially after the Sentinel-1A satellite had lifted,the higher spatial resolution and time resolution can be used to monitor the dam deformation more effectively.Based on the above ideas,this paper is mean to monitor the deformation of two typical dams,the Xiaowan dam and the Three Gorges dam,based on the InSAR technology:(1)Summarizing the research status of the development history and development trend of dam monitoring and InSAR technology,expounds the basic principle of InSAR technology and the main error sources of deformation monitoring;Introduces the basic features of Sentinel-1A data.(2)Using the ascending and descending orbit Sentinel-1A data to monitor the deformation of Xiaowan dam,and conversion the deformation information of the LOS director to the North-South director by the geometrical relationship;Estimate the water level of upstream by the SAR intensity image and DEM data;Analyze the relationship between the dam deformation and water level of the upstream.(3)Using Sentinel-1A data to monitor the deformation of the Three Gorges Dam,and analyze the relationship between the dam deformation and the water level of upstream,then give the different models of the dam deformation.This experiment would roughly determine the deformation magnitude and deformation trend of two dams,and combined the deformation with the information of variation of upstream water lever.In this paper,the feasibility of InSAR technology in the deformation monitoring of large engineering facilities such as dams and roads is verified to a certain extent.