A study of the influence of water level fluctuations on the geodynamic situation in the natural and technical geosystem of the Dniester HPP and PSPP cascade

Abstract

Purpose. Statistical information for the period from 2016 to 2021 was used to analyze seismic activity. Objective. The aim of the study is to identify the relationship between changes in water level and local seismic activity in the region. Using HPP and Psing filtering, the hypocenters of earthquakes within a radius of 30 km from the seismic station with the NDNU index were selected, and using geographic information technology tools, the hypocenters of earthquakes were compared with the geological structure of the region. Methodology. Statistical information for the period from 2016 to 2021 was used to analyze seismic activity. Using filtering, the hypocenters of earthquakes within a radius of 30 km from the seismic station with the NDNU index were selected, and using geographic information technology tools, the hypocenters of earthquakes were compared with the geological structure of the region. Results. The studies revealed a correlation between seismic events and water level fluctuations in the reservoir. The paper also established the density of episodes concentrated in the reservoir operation area, as well as the magnitude and shallow depth, indicated the probability of activation of faults located in geological layers close to the ground surface. The stresses in the soils were assessed. Using the Coulomb-Mohr theory, the ultimate stresses leading to the destruction of structural ties were calculated approximately, and the optimal modes of operation of the reservoir were determined. Originality. The research in the article allows us to more accurately assess the effect of the stress gradient in the soils on the background seismicity in the reservoir operation area. Practical significance. The practical significance of this study is understanding the effect of the stress gradient on induction earthquakes. The described method, which is based on the principles of Coulomb's law and Mohr's theory, allows us to remotely study the behavior of the material under different loading conditions. This study and the development of a geomechanical model helps to better understand and predict earthquake behavior and determine safe loading zones. This has practical implications for the design and construction of structures, as well as for risk assessment and appropriate safety measures.

Reservoir-triggered seismicity: case study of the Dnister Hydro Power Complex (Ukraine)

“…Dnister PSPP is located outside the main zone of seismicity. Another research [Zyhar et al, 2023] confirms the relevance of studying the impact of water level fluctuations on the geodynamic situation in the Dnister Hydro Power Complex, as well as the importance of continuous monitoring and development of risk management measures. This study looks closer at the Dnister HPP-1 region, in particular by expanding the earthquake database.…”