Geodynamic features of territories around Ukraine's Hydroelectric Power Plants based on GNSS CORS data

The study presents an assessment of the geodynamic characteristics of territories around Ukrainian hydroelectric power plants based on GNSS observations from countinious operating reference stations (CORS) of GeoTerrace and System.Net networks for the period 2019–2025. Daily solutions are computed using Bernese 5.2 software and subsequently transformed into the ETRF-2020 reference frame. The methodology includes the estimation of linear trends and annual horizontal velocities of GNSS stations in the north and east components. A filtering procedure was applied to exclude GNSS stations with insufficient observation duration, incomplete data series, suboptimal spatial configuration, as well as results affected by significant errors. The analysis encompasses GNSS networks located around Dnister Hydropower Complex, Dnipro Hydro Power Plant (HPP), and Kremenchuk HPP. For each of these sites, regional deformation vectors were determined, reflecting crustal compression or extension; motion of major lithospheric blocks; tectonic activity of rift zones; deep-seated faulting; and distributed stress fields. Dilatation distribution maps are constructed for each HPP territories, and the dilatation parameter at the dam location was estimated. Finally, the cumulative deformation of the dams induced by long-term geodynamic processes over their operational lifetimes was evaluated, showing deformation magnitudes at the millimetre level for all studied structures. The proposed methodology, based on permanent GNSS station networks, could be applied to other large engineering facilities in Ukraine and worldwide/