Monitoring large dams

Recording regional deformations using InSAR and GNSS on the Enguri Dam in the Caucasus Mountains, Georgia

The Geodetic Institute Karlsruhe is involved in the international research project DAMAST (Dams And Induced Seismicity Technologies For Risk Reduction - technologies for the safe and efficient operation of water reservoirs). The project is part of the funding measure Client II - International Partnerships for Sustainable Innovations in the framework program FONA³ (Research for Sustainable Development) of the Federal Ministry of Education and Research (BMBF).


The focus of the investigations in the DAMAST project is the 270 m high and 750 m long Enguri dam in the Caucasus Mountains in Georgia. The adjacent Enguri reservoir and the surrounding area are also the subject of the investigations. The security of the dam and thus the population is endangered by a variety of factors, such as earthquakes and landslides. In the course of the project work, safety-relevant parameters are to be recorded qualitatively and quantitatively.


The work at the Geodetic Institute focuses on regional deformation monitoring using the satellite-based measurement methods InSAR and GNSS. In the case of InSAR, radar data from the Terra-SAR-X, Sentinel-1 and ALOS-2 satellites serve as the data basis. This means that three different wavelengths can be evaluated in the X, C and L bands. A common process for processing radar data is Persistent Scatterer Interferometry (PSI), which gives good results for radar backscatter that is stable over time. Vegetation areas have insufficient stability in backscattering, especially for short wavelengths in the X and C bands, since the signals are already reflected close to the leaf crown. The study area mainly has forested areas, so that only a significant contribution to the regional deformation field can be expected by evaluating the L-band data. X and C band results, on the other hand, can provide spatially high-resolution information for locally exposed structures such as the dam itself. A research focus in the DAMAST project is the methodological development of alternative evaluation methods such as Partially Time Stable Scatterers and Distributed Scatterers. This enables regionally dense deformation fields with X and C band results.


Find out more about DAMAST on the project website.


GNSS test measurements at the Enguri Dam in Georgia