How to set up a dam monitoring system with PSInSAR and GPS
Dams are engineering structures with significant social and economic benefits as well as risks. A structural or operating failure of the dam poses a threat to nearby industrial sites, human settlements, and the environment. Usually, the consequence is an immense economic loss for the region. Therefore, it is of great importance to ensure dam health and functionality. The dead load of the dam body itself and the impounded water, among other things, can cause horizontal and vertical displacements of the dam body. If these displacements surpass a critical limit, the structural integrity of the dam is threatened. Therefore, the surface deformations need to be monitored. In this study, we discuss the different mechanisms, which lead to the deformation of a dam and how they can be monitored. First, an overview of the different construction types of dams currently in use is given. Whereby the focus is on embankment dams, since our main observation target, the Parapeiros-Peiros Dam, is an embankment dam. Second, the deformation processes an embankment dam may be subject to during its lifetime are described. Additionally, the conventionally used instruments and methods to measure these deformations, such as geodetic triangulation or optical leveling networks, are discussed. Based on the deformation processes known from the literature, we outlined what characteristics of an embankment dam need to be taken into account when setting up a deformation monitoring system. The monitoring system, we propose, works continuously and semi-automatically. The main task is to accurately map the surface deformations of the dam body and the surrounding area using SAR images and GPS positions of several control points. Afterward, changes in the behavior of the dam need to be identified and analyzed.