THE POSSIBILITIES OF GEOPHYSICAL METHODS APPLIED FOR INVESTIGATING THE IMPACT OF MAN ON THE GEOLOGICAL MEDIUM*

Geophysical methods can be applied to investigate the harmful effect of man's activities on the environment: the study of specific electrical resistivities and natural electric fields of filtrational origin makes it possible to control the penetration of exogenic pollutants into soil as well as desalinization and secondary salinization of soils; electrometric and seismometric methods allow to observe the groundwater level near water reservoirs thus evaluating the harmful effect of backing up natural groundwater flow; contrasting properties of bedrocks and rocks in a landslide body permit application of seismic and electrical prospecting methods. Observation of the changes in specific electrical resistivities with time on the slopes of quarries is an effective method of assessing slope stability and predicting landslide hazard.

Mining activities, groundwater pumping, and oil extraction are the main causes of endogenic pollution of geological medium; surface and borehole geophysical methods make it possible to assess vertical and horizontal displacements of the interfaces between salty and fresh subterranean waters resulting from an extensive exploitation of water supply sources; activation of geodynamic processes associated with mining activities is determined from the data of ‘regime’ electrometric, seismometric, gravimetric, and inclinometric observations. Geophysical methods are applied widely for studying the intensification of physico‐geological processes under the impact of man. A specific object of electrometric investigations is degradation of permafrost and intensification of karst processes in soluble rocks.

The principal advantage of geophysical investigations lies in the possibility of creating high spatial and temporal density of observations permitting an extensive employment of statistical methods in the assessment of the impact of man on the geological medium.