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ABSTRACT
The Bulgarian northern Black Sea coast is affected by many landslides. Several geodynamic networks have been built to study landslide processes in the northern Black Sea coast. Landslide research is important, as these phenomena can lead to great material damage. Their destructive impact on buildings, engineering structures and disturbances in the resilience of the earth's crust causes enormous economic, environmental, social and other damage, and often takes human lives.
A modern tool for monitoring landslides is the application of GNSS measurements, which has an advantage over conventional measurement methods. GNSS data from six continuously operating reference stations from National GNSS network for three years and a half period are processed and analyzed. Time series with coordinates and mean square errors (north, east and up) are obtained. Time series with the residuals from multi-year solution are obtained too. The time series show the very good quality of the solution (the values of nrms are between 0.60 and 0.80).
In this study long-term processing of data from continuously operating reference stations (CORS) is performed, to obtain the coordinates and velocities of the stations, because this also affects the local networks built for the study of landslides.
The velocities of the points from the National GNSS network in the northern Black Sea region are relatively small, less than 1 mm/year. To obtain the movements of the points from the local geodynamic networks, it is necessary to process their GNSS measurements together with the GNSS measurements from the continuously operating reference stations from National GNSS network but the velocities of the station must be taken in to account, as done in this study. This allows to determine whether the measured points are located in the landslide or outside it and thus to accurately determine landslide boundaries.
Keywords: GNSS, crustal movements, geodynamics, landslide monitoring
INTRODUCTION
According to the modern aspects of geodynamic research crustal movements, landslides and sea level changes are part of multifactor dynamic processes. The dependencies between them and other natural processes are considered as a complex system of interrelations that is difficult to describe and study. One of the main tasks of the current stage of research is to study in more detail the trends, patterns and dependencies in the development of these processes and...