Differentiation of kinematics of the Dnister HPP-1 dam (based on the data of GNSS monitoring of spatial displacements)

Abstract

The purpose of study is to generalize the vertical displacements of the GNSS network of spatial monitoring of the Dnister HPP-1 dam for the differentiation of its kinematics as well as to evaluate the impact of short-term geodynamic processes in the region. Object of study. The object of the study is the monitoring of the Dniester HPP-1 dam according to the GNSS network data of the stationary system for monitoring the spatial displacement of structures (SSMSDS) of the Dniester HPP-1. The basis of the Dnister SSMSDS are two base GNSS stations additionally equipped with a robotic total station, which are installed on a strong foundation and located at a distance of several hundred meters from the dam. There are control points equipped with a GNSS receiver, antenna and an angle reflector with a 3600 viewing angle on the crest of the dam. The results of GNSS measurements are transmitted to the Leica GNSS Spider software, which processes and determines the coordinates of the base and control points. The GEOMOS software performs a joint estimation of GNSS results and linear-angular measurements. Methodology. To generalize the displacements of GNSS stations of Dnister HPP-1 the method of statistical analysis of time series is used. Authors examine the covariance interrelationships between all GNSS stations of the stationary system for monitoring the spatial displacement of structures (SSMSDS) of the Dnister HPP-1, which are placed on the dam based on the results of measurements from 1.07.2017 to 31.03.2021. For the selected periods of anomalous short-term displacements, the average values of covariance for each GNSS station are calculated. Results. During the period from 1.07.2017 to 31.03.2021 and according to the results of covariance interrelation for most GNSS stations, 3 epochs of anomalous altitude displacements are established (T = 2017.8 ± 0.1, T = 2019.0 ± 0.1, T = 2019.4 ± 0.1). Based on the covariance analysis, it was found that for periods of anomalous vertical displacements, the kinematics of the GNSS station MP01 differs significantly from the kinematics of GNSS stations MP02-MP05. The kinematics of GNSS-stations MP02-MP05 is constant, which indicates the anomalous movement of the unit on which the GNSS-station MP01 is installed in relation to the other blocks of the dam of the Dnister HPP-1. Scientific novelty and practical significance. Authors proposed the method for studying the geodynamics possesses of large industrial areas covered by a network of GNSS stations. Based on the GNSS measurements the periods of anomalous displacement are reveled and further search for spatial kinematic interrelationships between pair of GNSS stations is established. The developed methodology can be used to differentiate the kinematics of structural elements with installed GNSS stations such as engineering structures, industrial areas, geodynamic polygons.

Geodesy, Cartography and Aerial Photography

“…Dnister Hydro Power Complex is under continuous monitoring: GNSS observation network is differentiated [Savchyn and Vaskovets, 2018], the relationship between construction stages and seismicity of the region is determined [Savchyn and Pronyshyn, 2020], kinematics of HPP-No. 1 dam are differentiated [Tretyak et al, 2021b] and the interrelation of altitude displacements of the GNSS sites due to non-tidal atmospheric loads are identified [Tretyak et al, 2021a]. A complex approach to data processing in a common centre for the preservation and visualization of the results of the Dnipro, Dnister, Middle Dnipro, and Kaniv HPPs has also been implemented [Tretyak et al, 2017].…”