Monitoring embankment dams from space using satellite radar interferometry: Case studies from RemoDams project

The monitoring procedures with different geotechnical/structural sensors and classical geodetic techniques including GNSS are the usual practices in most of the dams where these controls are established. Other geomatic techniques such as TLS, GB-SAR and multi-temporal InSAR (MT-InSAR), allow the determination of 3D displacements with the advantage of covering a large number of control points. In particular, MT-InSAR techniques enable the detection of displacements at a very low cost compared to other techniques, and without the need for field work or the installation of special equipment. In addition, they can provide a single source of information on the stability of the dam when monitoring programs are not carried out due to lack of funding, resources or other reasons. These techniques provide measurement uncertainties of the order of 1 mm/year, interpreting time series of interferometric phases of coherent reflectors present in the area, called Persistent Scatterers. In this work, we present the adaptation and application of MT-InSAR techniques to monitor embankment dams, obtaining vertical displacements, characterizing their consolidation rates, and allowing the identification of potential problems surrounding the reservoir that require further field investigation. This study is part of the ReMoDams project, a Spanish research initiative developed for monitoring dam structural stability from space using satellite radar interferometry.